Do-it-yourself hip roof. Construction of a hip roof: from the frame to the roofing

The hip roof is characterized by a large number of advantageous moments, among which are attractive geometry, uniform heating and protection of the structure from precipitation. Even strong gusts of wind do not affect such a structure, since it does not have gables. If we compare it with a gable roof, it can be noted that the probability of deformation of the hip roof is much less. It is possible to list the advantages of such a roof for a very long time, but we must not forget that the hip roof truss system is a rather complex structure. This fact can be a significant reason when choosing the type of roof. Despite this, private developers very often build a hip structure, due to its similarity to a hipped frame.

Some features of the hip roof

When comparing a hip and gable roof, you can immediately notice that there are no vertical gable walls in the hip roof device. They are replaced by triangular slopes located at the ends. Due to this, the visual and real volume of the roof is significantly reduced. From the economic point of view, the benefit of this is a moot point, since when cutting large sheets of roofing material into hips, there is an increase in costs.

Like any structure, the hip roof is conditionally divided into simple geometric shapes. The simplest option has symmetrical slopes: two in the form of a trapezoid and two in the form of a triangle. That is, the whole structure consists of four slopes, which served as the basis for the parallel name - a four-sided roof.

The side section of the hip roof resembles a conventional gable roof in the shape of a triangle. When visually inspected in profile, you can see a trapezoid, which is conditionally divided into a rectangle with unfolded triangles adjoining on the sides. The shape of the trapezoid is determined directly by the developer and depends on the ratio of the length of the ridge to the length of the cornice overhang. The part of the structure, which has the shape of a rectangle, is built on the basis of roofing standards for the construction of hanging and layered truss systems.

The hips that replace the gables must be installed with a certain slope, since the design provides for their connection with the inclined sides of the trapezium. It is the device of the hips that is the most difficult stage in the arrangement of the hip truss system. For those who decide to do the work by analogy with the usual pitched method, we can say that nothing will come of it. The thing is that the length of the ridge run does not correspond to the length of the slope, therefore, the rafter legs of the hips in the upper part, as well as the triangular parts of the large slopes adjacent to them, remain without support.

As a support, the design provides for the installation of special rafter legs that connect the ridge beam and the corners of the structure. A look at the hip roof from above allows you to notice that the sloping elements are diagonals, for this reason their second name is diagonal. In addition, the design of the hip roof implies that the diagonal will become a support for rafters of different lengths, which are installed at right angles to the overhang. These different-sized elements are called spawners.

Thus, the main elements of the hip truss system are:

• Ordinary hip roof rafters, the lower part of which rests on floor beams or Mauerlat. Depending on the type of support, the rafters can be hanging or layered.
• Diagonal rafter legs, necessary to connect the corners of the roof and the edge of the ridge beam. Such elements can be used both for the convex corners of the hip structure, and for the arrangement of the concave corners of the valleys.
• Sprockets - elements that create the plane of the hip and parts of the trapezoidal slopes that are adjacent to the diagonal rafters.

Description of diagonal rafters

Given the location of the diagonal rafters, it can be determined that their length will be greater than the same parameter of ordinary rafters. In addition, being a support for the spooks, they take on a rather large load. All this leads to the conclusion that the diagonal rafter legs should become reinforced. Most often, boards designed for ordinary rafters, but paired with each other, are used for this.

Paired braids allow you to solve three problems at the same time:

• Increasing the load without the risk of deformation of the truss system.
• Obtaining a solid diagonal element (building rafters leads to a weakening of individual sections).
• Reducing the cost of installing a truss system (two boards will cost much less than a solid beam).

The significant length of the diagonal rafters requires the installation of additional supports, the number of which is determined by the length of the diagonal.

Supports for diagonal elements

The design of the hip rafter system, regardless of size, requires the presence of supports that reinforce the diagonal rafter legs. With a sloping length of more than 9 meters, the installation of at least two supports is required. Spans of shorter length can be supported by one support located in the upper part.

The diagonal rafter legs can be supported by:

• Vertical posts installed directly on the ceiling. If the ceiling is reinforced concrete, then a piece of waterproofing material must be placed under the rack.
• The struts, which rest against the bed with their lower part and are located at an angle of 45 degrees, and the magnitude of the angle of inclination does not play a special role.
• Sprengels, which are made in the form of the letter "T" inverted. This element is used when the diagonal needs two or more supports (read also: ""). When installing, it is important to ensure that the base of the sprengel is perpendicular to the slope. In most cases, such supports are placed closer to the corner of the roof, that is, at the bottom of the rafters.

Additional supports are best made from twin boards and installed in places where the greatest load is expected.

The design of the reference points of the slopes of the rafters

The upper part of the slanting rafter leg rests against the ridge beam. The design features of the hip roof allow you to do this in several ways:

• If the roof structure has one ridge run, then the slope rests on the ridge console.
• If the rafter system has two ridge runs and ordinary rafters made of boards, then the slopes should rest on the truss, the base of which lies on the ridge runs.
• If the design provides for the presence of two runs, and the rafters are made of timber, then a surf is used instead of a sprengel. This element is made from cutting boards with a thickness of more than 5 cm and connects ordinary rafters to each other not far from the ridge.

Depending on the method of planting, the upper part of the braid is cut. You can fasten the diagonals with nails, while reinforcement with a twist of wire or a metal clamp is allowed.

In the lower part, the diagonal rafters of the hip roof supported by the Mauerlat are fastened with metal brackets or corners directly to the Mauerlat or to a specially installed corner beam.

The device of the conjurers

By means of the spears, hips and triangular parts of large slopes are formed. In the upper part, the element rests on a diagonal rafter, at the bottom - on a Mauerlat or floor beams.

The guards are installed in two ways:

• With the help of a notch. In the diagonal rafters, nests are cut down at a distance of 20 cm from each other, while it should be remembered that the cutting of the sprigs of adjacent slopes should not be performed opposite each other.
• Installation of cranial bars, which will act as supports for the sprigs. To do this, take the bars 5 * 5 cm and chop them on the lower part of the braid. This option is considered more efficient, since cutting can weaken the strength and stability of the slat. In addition, the use of this method allows you to place the sprigs opposite each other.

The fastening of the sprigs in the lower part is carried out by analogy with the installation of ordinary rafter legs.

Installation of a simple hip rafter system

The easiest way to build a hip roof is to buy a finished truss system and install it. But building a hip truss system with your own hands will bring more pleasure and allow you to create a structure that matches the entire structure. To make sure of your own strength, you can practice on small buildings, for example, build a hipped roof over a gazebo or summer kitchen.

The creation of the simplest hip roof takes place in several stages.

Stage 1. Creation of a roof model and drafting.

The construction of any structure is preceded by the design stage. This helps to determine the shape of the structure and acquire the right amount of material. A simple hip roof does not require a complex drawing, it is enough to draw by hand an approximate diagram of the hip roof rafters.

To draw up the simplest hip roof project, it is enough to follow the steps described in the following instructions:

• The parameters of the structure are determined, according to which an approximate drawing of the roof is drawn up in profile and full face. In order for the drawing to correspond to real parameters, it is necessary to select a scale, most often 1:25 is chosen. This means that the size should actually be divided by 25.
• The roof contour drawing helps to choose the optimal roof height, and in several versions. The most suitable pattern measures the angle of inclination of the slopes.
• Further in the figure, the points of installation of the layered rafter legs are marked, while each side must be divided into equal sections. The pitch of the hip roof rafters should be optimal so as not to increase the consumption of building material, but also not to reinforce the structure with an additional counter-lattice.
• The next step is to determine the length of the skate. It should be remembered that this part of the structure must connect a whole number of roof trusses. On both sides of the long side, you need to set aside the same segments.
• Based on the figure, the required amount of material is calculated.

The number of fasteners is determined by the number of rafter legs, taking into account all nodal fasteners. For each rafter, you need to purchase two corners. Boards are best bought with a small margin so that you can eliminate random errors in construction. If the structure is being erected on a concrete or brick box, then care should be taken to purchase a beam from which the Mauerlat for the hip roof will be constructed.

Stage 2. Installation of the main part.

Installation of the hip truss system begins with the installation of the ridge part:

• Directly in the middle of the walls, to which the hips will adjoin, one board is nailed. A construction cord is pulled between them, which must pass strictly along the central axis.
• Two rafters are applied from one of the ends of the structure, their intersection should pass under the cord. The cut line of the upper heel of the rafter leg is marked, taking into account the ridge run about 5 cm thick. The necessary part of the element is cut down so that the envelope roof is of the required shape.
• According to the workpiece made, the rest of the rafters are sawn. It should be remembered that when erecting a hip roof with hanging rafters, the length of the cornice overhang is taken into account.
• Farms are assembled from two rafter legs and fastened to one nail.
• A ridge beam is installed through all the farms and rafters are nailed to it.
• In the lower part, the layered rafters are attached to the Mauerlat, the hanging rafters of the hip roof are attached to the floor beams. In both cases, fastening is performed using metal corners.
• Previously nailed auxiliary boards can be removed, as they are no longer needed.

Stage 3. Construction of hip slopes.

The rafters of the hip part are attached by analogy with ordinary rafter legs: the top is fixed with nails, the bottom - by means of corners to the Mauerlat or the upper log.

The installation is carried out as follows:

• Expose the first diagonal rafter and put a mark at the place of the saw cut. In this case, the lower part of the element should be located in the corner of the roof.
• Saw off the element along the intended line and fix it: top - with nails, bottom - with corners.
• The remaining diagonal rafters are installed in a similar way.
• To fill the hip slope, the sprigs are tried on and installed individually.
• After that, they proceed to the installation of the sprigs of the main slopes.

After installing all the elements of the truss system, the following is done: using a wire twist, every second rafter is tied to a log of the second row or to wooden plugs that were previously laid in the walls. In addition, stranded wire can be embedded in masonry or between blocks during wall construction. It should be remembered that from the top to the location of the twist should be at least three rows of bricks or two rows of blocks.

The finished truss system is closed with a crate. If the coating is soft, then the crate should be solid boards, plywood or OSB boards. Rigid roofing materials can be laid on a crate made of a bar nailed with a certain step.

Construction of a complex hip roof

The frame of a complex hip roof is being built in a similar sequence, but with minor modifications. For example, diagonal rafters should be fixed in a more durable way, with the installation of additional supports. The ridge part is installed after the installation of the support frame, which includes the bed at the bottom and the ridge run at the top.

It is much more difficult to build a hip roof truss system than a conventional gable roof structure. However, a hipped roof looks more attractive both over a house and over a light building.

Having tested your strength in the construction of a hip roof over a gazebo or other household building, you can achieve a good result in the independent construction of a four-pitched roof over a residential building.

Making a hip 4-pitched roof is more difficult than the usual classic gable roof, however, such a roof looks much more interesting not only on the house, but also on any building, gazebo. In addition, protection from precipitation and winds in such a roof structure is higher than usual. So if you have at least a little experience in the construction of truss systems, then you can easily figure out how to do it, and we will help with this with our advice.

For a hip roof, there are 2 main options for constructing a truss system. This is with the support of the rafters on the Mauerlat and on the beam. A lot of controversy goes on each of the methods. Let's say right away that the method recommended by our portal "Construction and Repair" with support on a beam is simpler and easier. Why exactly it is more popular, and has more advantages, we will analyze below.

Features of attaching rafters to beams

Rafter systems come in 2 basic types: layered and hanging. More about each of them review Types of truss systems for a gable roof. For hip roofs, the truss systems are similar, although they have additional elements.

Fastening rafters to beams is most often used for the construction of light mansard-type roofs.

Making a roof frame supported by beams is the easiest way to build a roof. Most often it is used in wooden houses made of timber / logs or if there is a monolithic concrete beam at the top of the wall, since such walls will evenly distribute the load from the roof due to the material.

In brick houses, etc. hip roof with rafters resting on floor beams will give an uneven point load on the walls, and very quickly the walls will begin to collapse, crack and crumble.

But it is easy to get out of this situation: it is necessary to lay the Mauerlat, and on top of it to fix the floor beams. The walls will not collapse, since the mauerlat will distribute the pressure of the roof.

In addition, it is irrational to embed the rafters into the Mauerlat, as this will reduce its strength.

Methods for attaching rafters to beams

You can attach the rafters to the beams in different ways. The main requirement is that the fastening is strong, and the elements do not slip off.

Method 1. Grooves with spikes. With this method, the corresponding grooves and a spike in the middle are cut in each element, which prevents the rafters from moving to the sides.

Method 2. Metal mount. It could be a bolt and a nut. On the underside of the beam, a triangular cut is made under the place where the rafters are attached. A rafter with a beam is drilled so that the hole goes into the cutout made. And a bolt with a nut is threaded through it.

It should be noted that the first method is most often used, since the metal fastening reduces the stability of the truss system. Therefore, preference is given to joints with a spike/tooth/stop.

Hip roof with rafters resting on floor beams it will be more stable if you use fasteners not with 1 tooth, but with two. Such fasteners are especially necessary if the roof has a gentle slope angle, is subject to increased climatic loads. This type of fastener improves the adhesion of elements, increases the contact area, as well as the strength of the entire assembly. For steep roofs, fastening with 1 spike is sufficient.

Tip: all slots and sockets to keep the beam from being weakened should be cut to 1/3-1/4 of the beam depth. And so that there is no chip, the tie-in is made 25 or more centimeters from the edge.

But do not think that the grooves themselves will hold the rafters, you will still need additional metal fasteners. It can be nails, clamps, pads.

You can study other types of roofs in our review What are roofs according to a constructive solution.

We have already talked about the hip roof in one of the previous articles on the site. There was described the design of the roof with the support of the rafters on the Mauerlat. After the publication of the article, I received many requests to show how to make a hip roof with rafters resting on floor beams, and also to answer the question of whether it is possible to make a hip roof with different slope angles.

Thus, I wanted to “kill two birds with one stone” with one example. Now we will consider the construction of a hip roof with rafters resting on floor beams and with different slope angles.

So, let's say we have a box of a house made of heat blocks (polyblocks) 8.4x10.8 meters.

STEP 1: Install the Mauerlat (see Fig. 1):

Picture 1

STEP 2: We install long floor beams with a section of 100x200 cm in increments of 0.6 meters (see Fig. 2). I will not dwell on the calculation of beams anymore.

Figure 2

The very first we put beams that run strictly in the middle of the house. We will navigate along them by installing a ridge beam. Then we put the rest with a certain step. For example, we have a step of 0.6 meters, but we see that 0.9 meters are left to the wall, and one more beam could fit, but it does not. We leave such a span especially for "removals". Its width should not be made less than 80-100 cm.

STEP 3: Installing takeaway. Their step is determined when calculating the rafters, about which a little later (see Fig. 3):

Figure 3

For now, we only put the extension corresponding to the length of the skate, which will be equal to 5 meters. The length of the ridge is greater than the difference between the length and width of the house, which is 2.4 meters. What does this lead to? This leads to the fact that the corner rafter will not be located at an angle of 45 ° in plan (in the top view), and the angle of inclination of the slopes and hips will be different. For slopes, the slope will be more gentle.

It is enough to fix the removal on the Mauerlat with nails. We attach them to a long floor beam, for example, like this (Fig. 4):

Figure 4

There is no need to make any cuts in this knot. Any washed down will weaken the floor beam. Here we use two LK-type metal truss fasteners on the sides and one large nail (250 mm) driven through the beam into the end of the stem. We hammer the nail with the very last one, when the stem is already fastened to the Mauerlat.

STEP 4: We install the ridge beam (see Fig. 5):

Figure 5

All elements of this design, except for the struts, are made of timber 100x150 mm. Struts from a board 50x150 mm. The angle between them and the overlap is at least 45°. We see that under the extreme racks there are bars resting immediately on five floor beams. We do this to distribute the load. Also, to reduce the load on the floor beams and transfer part of it to the load-bearing partition, struts were installed.

We determine the installation height of the ridge beam and its length for our house ourselves, making a preliminary sketch on paper.

STEP 5: We manufacture and install rafters.

First of all, we make a template for the rafters of the slopes. To do this, we take a board of the desired section that is suitable in length, apply it, as shown in Figure 6, and make markings using a small level (blue lines):

Figure 6

The height of the bar, which we put on the takeaway for marking the lower gash, is equal to the depth of the upper gash. We made it 5 cm.

According to the template obtained, we make all the rafters of the slopes, based on the ridge beam, and fix them (see Fig. 7):

Figure 7

In such structures, where the rafters do not rest on long floor beams, but on short extensions, we always put small supports under the rafters above the Mauerlat, forming, as it were, a small triangle and unloading the attachment point to the beam (see Fig. 8):

Figure 8

It is not necessary to bring these supports further inside the roof, and even more so to put them at the junction of the removal with the beam. Most of the load from the roof is transmitted through them (this can be seen in the calculation program) and the floor beam may simply not withstand.

Now a little about the calculations. When choosing a section of rafters for a given roof, we calculate only one rafter - this is the rafter of the slope. It is the longest here and its angle of inclination is less than the angle of inclination of the hip rafters (explanation - we call a roof slope in the form of a trapezoid a slope, a hip - a roof slope in the form of a triangle). Example results in Figure 9:

Figure 9

Yes, I forgot to say. Who has already downloaded this calculation program from my website before December 1, 2013. There is no ʺSling.3ʺ tab. To download the updated version of the program, go to the article again at the link:

This article has also been slightly corrected due to feedback from some readers, for which special thanks to them.

STEP 6: We add the takeaway and fasten the wind boards (see Fig. 10). We add enough offsets so that there is room for attaching the corner offset. Wind boards at the corners are just stitched together, controlling their straightness. Check visually for sagging corners. If so, put temporary props under them directly from the ground. After installing the corner offsets, these supports are removed.

Figure 10

STEP 7: We mark and set the corner offset.

To begin with, we need to pull the cord along the top of the floor beams, as shown in Fig. 11

Figure 11

Now we take a beam of suitable length (the cross section is the same as for all extensions) and put it on top of the corner so that the lace is in the middle of it. From below on this bar with a pencil we mark the lines of cuts. (see fig. 12):

Figure 12

We remove the lace and install the timber sawn off along the marked lines (see Fig. 13):

Figure 13

We attach the corner offset to the Mauerlat with the help of two roofing corners. We fasten it to the floor beam with a 135 ° corner and a large nail (250-300 mm). Corner 135 °, if necessary, bend with a hammer.

Thus, we put all four corner offsets.

STEP 8: We manufacture and install corner rafters.

At the hip roof, which I described earlier, the angles of inclination of the slopes and hips were the same. Here, these angles are different and therefore the corner rafter will have its own characteristics. We also make it from two boards of the same section as the rafters. But we sew these boards together not quite usually. One will be slightly lower than the other (about 1 cm, depending on the difference in the angles of the slopes and hips).

So, first of all, we pull 3 laces on each side of the roof. Two along the corner rafters, one along the middle hip rafter (see Fig. 14):

We measure the angle between the lace and the angular offset - the bottom washed down. Let's call it "α" (see Fig. 15):

Figure 15

We also mark the point "B"

We calculate the angle of the upper gash β = 90°- α

In our example, α = 22° and β = 68°.

Now we take a small piece of board with a rafter section and saw down one end on it at an angle β. We apply the resulting blank to the ridge, combining one edge with the lace, as shown in Fig. 16:

Figure 16

On the workpiece, a line was drawn parallel to the side plane of the adjacent slope rafter. On it, we will make another gash and get a template for the upper gash of our corner rafter.

Also, when we apply the workpiece, it is necessary to mark point “A” on the rafter of the slope (see Fig. 17):

Figure 17

Now we make the first half of the corner rafter. To do this, take a board of suitable length. If one board is not enough, we sew two boards. You can temporarily sew it by trimming an inch about a meter long into self-tapping screws. We make the upper washed down according to the template. We measure the distance between points "A" and "B". We transfer it to the rafters and make the lower washed down at an angle "α".

We install the resulting rafter and fix it (see Fig. 18):

Figure 18

Most likely, due to its length, the first half of the corner rafter will sag. It is necessary to put a temporary stand under it approximately in the middle. It is not shown in my drawings.

Now we make the second half of the corner rafter. To do this, we measure the size between the points "C" and "D" (see Fig. 19):

Figure 19

We take a board of suitable length, make the top cut at an angle β, measure the distance "C-D", make the bottom cut at an angle α. We install the second half of the corner rafter and sew it with the first nails (100 mm). We drive the nails into a run-up after about 40-50 cm. The result is shown in Fig. 20:

Figure 20

The upper end of the second half of the corner rafter must be cut down again. We do this with a chainsaw right in place (Fig. 21):

Figure 21

In the same way, we make and install the three remaining corner rafters.

STEP 9: We install racks under the corner rafters. First of all, it is imperative to put a rack resting against the junction of the corner offset with the floor beam (see Fig. 22):

Figure 22

If the length of the span covered by the corner rafter (its horizontal projection) is more than 7.5 meters, we put more racks at a distance of about ¼ of the span from the top point of the corner rafter. If the span is more than 9 meters, add racks in the middle of the corner rafters. In our example, this span is 5.2 meters.

STEP 10: We install two central rafters of the hips. At the beginning of the 8th step, we already pulled the laces to measure them.

We make the rafters in this way - we measure the angle of the lower gash "γ" with a small one, we calculate the angle of the upper gash "δ":

We measure the distance between the points "K-L" and make a rafter along it. We cut the ends at the corners we have determined. After that, the upper end must be sawed again (sharpened) taking into account the angle "φ", which is also measured using a bevel (see Fig. 23):

Figure 23

STEP 11: Adding takeaway to the corners. We make the most extreme extensions that do not reach the Mauerlat lightweight, from a board 50x200 mm (see Fig. 24):

Figure 24

STEP 12: We install the guards. How to make sprigs, I described in detail in the first article about the hip roof. Here the principle is absolutely the same, so I will not repeat myself (see Fig. 25):

Figure 25

We fasten the sprigs to the corner rafter using a 135 ° metal corner, bending it if necessary.

After installing all the sprigs, it remains for us to hem the cornices from below and make a crate. We have already talked about this many times.

Construction of X-shaped (octagonal) roofs.

Construction of a T-shaped roof of the house.

Installation of an L-shaped roof with gables of various widths.

L-shaped roof of the house with equal gables.

Do-it-yourself hipped roof of the house.

Look, this way you can “slow down” your electric meter by 2 times! … Completely LEGAL! You need to take it to the one closest to the counter ...

If you have now come close to the issue of choosing the design of the rafter system, the first thing you need to decide is how exactly you will transfer the load from the roof to the house. For example, in the classical scheme of the rafter system, the rafters evenly rest with their ends on the walls or Mauerlat, around the entire perimeter or on both sides, depending on what shape the slopes are. But often today the rafters are attached directly to the attic floor beams, and not to the Mauerlat, and this technology has its own valuable advantages.

And how to properly install the roof rafters on the floor beams, what technical solutions exist and how to make such attachment points - we will now tell.

When is it advantageous to lean rafters on beams?

Of course, building a roof with a Mauerlat is more understandable and logical, because. this method has been practiced for a very long time and has been studied, but you need to study the support of rafters on beams, and you will not find so much useful information as provided by our site anywhere.

But when is such a rafter system needed and why such difficulties, you ask? See, the approach is indispensable when:

• the construction site has rather fragile walls and it is difficult to lay a Mauerlat on them;
• the roof is being rebuilt on the old house, and the bed is already old;
• the rafter system is quite complicated and it needs intermediate supports, but there are none inside the house;
• for someone who builds a house, this method in itself seems more acceptable.

And it’s hard to imagine a real mansard roof without rafter support directly on the beams outside the walls:

Convinced? Believe me, this technology has as many advantages as the classical one.

How to create a reliable foundation for rafters?

The first step you need to take is to build a solid foundation for these rafters. For example, if the floor beams do not have any support (at least in the form of an intermediate wall of the house), then the roof trusses on it should be organized only according to the hanging principle. If there is a support, the rafters can be safely supported directly on the beam without any auxiliary elements.

In simple terms, if the beam in the attic floor is installed securely and has its own supports, then rafters can also be installed on it, and if all this is not there, then it makes sense to firmly connect the rafters with the beams themselves and hang them as a single system. Otherwise, before building the roof, you need to support the beams from the inside of the room, for which there are three different construction methods:

• The most simple the classic support consists of a puff, one sub-beam and struts. The puff is suspended in the middle. Such suspension systems are used today most often for large spans.
• Double the support consists of a puff, hangers, two struts and a crossbar, which serves as a spacer between the boards.
• There is even triple a strut, which is a separate three suspension systems, or one double suspension system and one simple. This is already a complex truss system.

Here's what these systems look like:

Ideally, if you can also calculate such beams for deflection and tension, how much they are ready to hold the entire roof on themselves. There are special online calculators and formulas for this, although it will also be enough for your own peace of mind to invite an experienced carpenter.

Methods for connecting rafters with beams

So you have two main paths:

1. Install the floor beams first, mounting them into the walls, thereby creating a layered truss system.
2. Assemble the roof trusses on the ground and raise them to the roof ready, while the lower tightening of the trusses will simultaneously serve as a support-beam for the future attic floor.

Each of these methods has its pros and cons, but different methods of fastening are used - for trusses, metal or wooden plates are usually fastened, and for assembly on the roof, chipping and cutting into a spike.

Hanging rafters: puff and beam in one role

If we are talking about a small construction site, like a garage, a bathhouse or a change house, then it is enough just to make truss trusses on the ground, and only then raise them to the walls of the building, fixing them on special Mauerlat pins. Here, floor beams are an integral part of the trusses themselves, and this is the very case when the puff in the truss also serves as a support for the attic floor.

And here is how it is implemented in practice:

But about the options when the rafters are based on the floor beams, and do not create a single system with them, we will now examine in more detail.

Rafter rafters: support on beams at several points

Here is a modern master class in the construction of a classic attic roof, in which the rafters rest on the floor beams directly on the roof, and do not build trusses on the ground:

Here, the floor beams are no longer part of a single truss truss, but an independent element on which the entire truss system relies. Moreover, the support occurs not only on the sides of the beam, but also along its entire length.

How to install rafter legs on floor beams?

As soon as the floor beams are ready for the installation of rafters on them, proceed to the manufacture of the rest of the structure and the connection of the rafters to the beams.

To connect the rafter leg to the beam, its end is cut off at the right angle, or a more complex cut into spikes is made. Let's look at both of these options.

Joining a rafter to a beam without cutting

You can do without cutting, if you then use fasteners - this is a normal solution. So, to make a simple cut on the rafters, make a template:

• Step 1. Take a building square and attach it to the board.
• Step 2. Mark the cut at the top of the rafter.
• Step 3 Using a wood protractor, draw a parallel line to the first saw across the rafter. This line will help you determine the line from the weight on the edge of the building.

Here's what it looks like in practice:

It is much easier to make such rafters than for cutting. The main thing is to correctly determine the angle of inclination of the roof and the correct place for the future cut:

As a result, in life, such a design looks like this at a gable roof:

Types of cutting the rafter leg into the floor beam

The mounting configuration itself is more dependent on the angle of inclination of the slope. For example, for steep pitched roofs where there is little snow load, you can use a single tooth fastener. With the single tooth method, additional spikes are often made to help the rafters not move under loads. And under such a spike, you will already need a nest in the beam.

But, for sure, you know that any such places can weaken the beam, and therefore their depth should be no more than 1/4 of the thickness of the beam and no closer than 20 cm from the edge of the beam (so that a chip does not form).

But if you have a roof with a slope of less than 35 degrees, then it makes sense to use a double tooth, because such an attachment allows you to achieve high knot strength. As in the previous version, you can add two spikes.

With this method, each tooth can be either the same depth or different. For example, you can cut the first tooth only 1/3 of the thickness of the support beam, and the second already half:

The bottom line is that two rafter legs in a structure supported by beams are fixed with a puff. But, if the ends of these legs slide, then the integrity of the puff will be quickly broken. To prevent such a slip, it is necessary to insert, or rather, cut the rafter leg into the puff itself with the help of a tooth - with or without a spike.

In the process of cutting the rafters to the end of the puff, you need to move the tooth as far as possible. If you need to strengthen the fastening of such rafters, then use a double tooth. Another point: the teeth themselves can be of different sizes.

And finally, it is desirable to fasten the end of the rafter legs with twisted wire so that the wind cannot tear off such a roof. It is better to take a galvanized wire as a wire, and fasten it with one end to the rafter leg, and with the other end into a crutch, which is previously laid in the wall masonry at a distance of 30-35 cm from the top edge.

Here is a good example of a neat rafter cut for tightening, which at the same time serves as a floor beam already in a hipped roof:

Metal fasteners for such a node are still necessary, because the notch itself cannot hold the rafter legs under load.

Types of fasteners for nodal connections with a beam

Let's look at how to connect the rafters to the floor beam:

One of the most reliable is a bolted connection, which uses a set of bolts, nuts and washers. So, do everything step by step:

• Step 1. At the protruding end of the beam on its back, make a triangular cut so that its hypotenuse is at an angle the same as the angle of the rafters.
• Step 2. At the same angle, file down the lower part of the rafter leg.
• Step 3 Install the rafters with a cut directly on the beam and fix with nails.
• Step 4. Now shoot a through hole for the bolt.
• Step 5. Put on the bolt and fix the assembly with the nut.

Another quite acceptable option is to fix the rafter and the beam with special metal fasteners:

And here is an example of making wooden fasteners for the same node:

If possible, fix such rafters on beams with forged wire on a special anchor that is mounted in the wall.

Additional design "chair" for supporting rafters on beams

Sometimes the installation of rafters on floor beams is a rather complicated undertaking, in which the beams themselves serve as a 100% support for the entire roof, and it is important to do all this as competently as possible.

In order for the rafter itself to turn out to be sufficiently strong and reliable in practice, the so-called “chair” is used as supporting elements. These are the truss details that connect all the elements together, and in the context it really looks like four legs of a stool:

In fact, the “chair” is the struts that support the run to its entire height. Those. such a "chair" usually contains vertical posts, inclined posts and short struts. With its lower end of the rack, the chair cuts into the lower belt of the truss system or lies perpendicularly, or immediately into the floor beams. There are also different types of such chairs, depending on whether they rest on beams or directly on the rafters.

Here is a good example from this series:

And this is already an example of an unusual design of the truss system, in which the rafters themselves rest on the floor beams along and across, and the structure of the so-called support chairs is clearly visible:

Combined system: alternate supporting rafters

Today, such a variant of the roof is also practiced, which consists of several especially strong trusses located at a distance of 3-5 meters from each other, and the gap between them is filled with construction pairs.

In simple terms, several powerful main trusses are installed on the roof, two or three, and they hold the entire run on themselves. And already in the space between the main trusses, ordinary rafters rely on such runs, according to a simpler scheme.

Those. here, not all rafters rest on the floor beams, but only some, and the rest rely on the Mauerlat. Thus, the entire load is wonderfully distributed! And the concept of such a system is simple: the main trusses are made according to the scheme of hanging rafters, and the secondary rafter legs are made according to the principle of layered ones, while relying only on the bed:

In fact, the whole secret of such a combined system is that layered rafters are laid directly on the triangular hinged arches. In such a cunning way, bending stresses completely disappear from the hanging rafters, and only tensile stresses remain. And this suggests that here it is possible to significantly reduce the cross section of the truss elements. In other words, save money!

As you probably guessed, in your case, the way the rafters are supported on the floor beams will depend on what object you are building: a garage, a bathhouse, a country house or a whole country complex. In any case, all these methods have been tested, are actively used today in practice and deserve attention no less than the more familiar use of the classic Mauerlat.

1. Supporting rafters - on floor beams or on Mauerlat

   Please help me understand.
   
   How right?

2. Registration: 28.01.11 Messages: 196 Acknowledgments: 163
   

   The weight of the roof, roofs + snow loads must be transferred to the mauerlat, which in turn evenly distributes them and transfers the above loads to the load-bearing walls.

3. Registration: 06.12.09 Messages: 80 Acknowledgments: 7
   

   With this I completely agree. It turns out that the builders “make their work easier” by making the beams come out and fixing the truss system to them?

4. Registration: 06.12.09 Messages: 80 Acknowledgments: 7
   

   Although this method was noticed, it was mainly on hip and hipped roofs and mainly on one-story houses, where the wind component is lower

5. Registration: 09.06.12 Messages: 1.114 Acknowledgments: 3.262
   

   But all the effort is on the edge of the beam. The roof is large, it seems to me that the beams will break over time.

   At the same time, it will be easier to assemble the rafters and hem the cornices.
   There will be no thrust on the walls (as when relying on maurlat)
   Savings on several rows of walls, you can not use the Mauerlat (attach the beams to the armored belt).

   My personal opinion

6. Registration: 06.12.09 Messages: 80 Acknowledgments: 7
   

   I thought about this option. The fastening of the beam goes to the armored belt through the galvanized corners - there are nails on the dowel. Throw up? Mauerlat even clings to immured studs.

7. 
   

   Download the book A. A. Saveliev. - Rafter systems. Somewhere on the forum like.
   And also on this site -. I myself build on the basis of these sources. The main thing you need to understand is the principle of each node and whether it is needed or not on your roof.

8. Registration: 02.07.13 Messages: 325 Acknowledgments: 198
   

   And here are all sorts of squeezes from SNIPs, etc. for nodes.

9. Registration: 02.07.13 Messages: 325 Acknowledgments: 198
   

   Please help me understand.
   A one-story house made of aerated concrete 12x12 is planned. Ceilings - wooden beams. Reading books and watching videos does not give a clear answer yet. The roof is planned to be hipped. Along the perimeter on the armored belt, as I understand it, maurlat. And then I saw two options. The first is the support of the rafters on the Mauerlat, the floor beams are also placed on the Mauerlat and do not go outside the house. At the same time, the rafter hangs down and a cornice knot is made. It takes longer to make a cornice knot, but at the same time, the load goes to the armored belt, which is the rule at a glance.
   The second option - floor beams are placed on the Mauerlat and stick out of the walls by a meter, the rafter is attached to the end of the beam. Thus, the rafter does not twist below the level of the armored belt and it is easier to make the filing. But all the effort is on the edge of the beam. The roof is large, it seems to me that the beams will break over time.
   How right?

   in my opinion, for houses made of aerated concrete, only a non-thrust structure should be at the roofs

10. Registration: 06.12.09 Messages: 80 Acknowledgments: 7
11. 
    

    Another question about the racks - how to place them on the corner rafters of the hip roof?

    As well as under the rafters, truss trusses may need to be added.

    In general, racks are placed above the supports (vertically) or very close to them.

12. Registration: 06.12.09 Messages: 80 Acknowledgments: 7
    

    Well, in principle, I understood, I looked at the links. He answered many questions for himself. Previously, there was an opinion that such an arrangement of a rafter-beam was only for verandas (by the way, they write so in textbooks) and for not very important sheds. But the stands will help in principle. If only the ceiling from a strong wind did not walk. Crack, etc. - this is unpleasant

13. Registration: 13.05.12 Messages: 755 Acknowledgments: 437
    

    Do I understand correctly that leaning on beams is possible only for hanging rafters?

14. Registration: 26.07.08 Messages: 16.114 Acknowledgments: 4.832
    

    Not necessarily, there are combinations - one slope one ... another another

15. Registration: 12.08.09 Messages: 640 Acknowledgments: 260
    

    It will not break with supports in the area of ​​​​armo-belt, the vertical load will just pass on it, a tensile load will remain at the ends of the beams

    These small supports do not solve anything and practically do not transmit anything anywhere.

    If the rafters are hanging, then the vertical load is small compared to the spread. The spacer perceives floor beams - such a triangular truss type.
    If the rafters are layered, then it is better not to support them on the cantilevered removal of the beam without calculation

Hip roofs offer an impressive list of compelling benefits. Among them are a spectacular shape, uniformity of heating and reliable protection of the house from precipitation. Due to the absence of gables, hip structures are not afraid of significant wind loads. Compared to gable options, there is much less reason to fear deformations.

The list of pluses can be continued, but their flow is slowed down by a very weighty circumstance: the hip roof truss system does not please with the simplicity of the device. However, complexity will not stop an independent builder if he is familiar with the nuances of building a hipped frame.

Hip roofs differ from their gable counterparts in that there are no vertical walls of gables in their design. The place of the pediments was taken by triangular slopes located at the ends, significantly reducing the real and visual volume of the roof.

The economic effect of volume reduction is a moot point. When cutting large-sheet material into hip slopes, costs, on the contrary, increase. For example, laying a profiled sheet or will force you to fork out for the purchase of a coating one and a half times more than for the arrangement of a standard pitched structure.

The purchase of piece material will reduce the construction budget, because you won’t have to spend money on sheathing the ends of the roof.

By analogy with any of the building structures, the hip roof can be divided into simple geometric shapes. In the simplest version, without conjugations and valleys, she has two pairs of symmetrical slopes: two triangles and two trapezoids. On this basis, the hip roof received the parallel name "four-pitched".

Viewed from the front, its section resembles an ordinary triangular gable roof. In profile, the structure has a trapezoidal configuration, which can also be divided into a rectangle with two mirror-image triangles on the sides.

The shape of the trapezoid depends on the architectural preferences of the owner. It is determined by the ratio of the length of the cornice overhang to the length of the ridge. The part of the structure, bounded by a rectangle, is constructed in accordance with hanging or layered technological roofing standards.

The hips that replaced the gables are set at a certain angle to the horizon, because. they are obliged to adjoin the inclined sides of the trapezoid. It is in their device that the main snag of the hip truss system lies, because it will not work with the usual pitched method. After all, the ridge run does not completely cover the slope. Therefore, the rafter legs of the hips and the triangular parts of the large slopes associated with them literally have nothing to lean on with their upper heels.

The support for them will be special sloping rafter legs connecting the ridge run with the corners of the structure. If you look at the hip rafter structure from above, then the rafters will look like diagonals.

The installation direction was the reason for obtaining the second technological name - "diagonal". Naturally, rafter legs of different sizes in length will rely on the diagonals, because. they are installed perpendicular to the roof overhangs. They have their own name - narozhniki.

Summing up the information, we get that the following will be involved in the construction of the truss frame for the hip roof:

• Ordinary rafter legs, resting on the lower part on the Mauerlat or on the floor beams. Depending on the type of support, they can be hanging or layered.
• Diagonal rafters connecting the corners of the roof and the edges of the ridge run. Note that they are used not only in the arrangement of the convex corners of the hip roofs, but also in the construction of the concave corners of the valleys.
• Narozhniki, forming the planes of the hips and parts of large slopes adjacent to the rafters.

The installation of hanging and layered rafter legs is carried out according to the rules according to which it is being built. We will deal with their diagonal counterparts and with rafter half-legs-spiders.

Diagonal rafter legs

Taking into account the diagonal arrangement, it is easy to guess that the length of the slopes is greater than the length of ordinary rafter legs. In addition, they serve as supports for the sparrows. In view of what the rafters are loaded one and a half times more than ordinary analogues. Therefore, it is customary to make them paired from two boards with a section equal to the same size of material for ordinary rafter legs.

Pairing of slanted rafters simultaneously solves three technical problems:

• Allows you to safely increase the load due to the double cross-section of the bearing element.
• Provides the opportunity to obtain a diagonal structural element of any length without sections weakened by building.
• Eliminates the need for purposeful purchase of rafter timber.

Due to their length, diagonal rafters need additional supports, the number of which depends on the length of the rafter leg.

Supports for diagonal rafters

Regardless of the scale of construction, any scheme of the hip roof truss system includes supports to reinforce the diagonal rafter legs. If the design size of the swath is more than 9m, i.e. it covers a span equivalent in meters, its stability is provided by two additional supports. For smaller spans, one support located in the upper zone of the span is sufficient.

As a support for the diagonal rafters can be used:

• Rack installed vertically directly on the ceiling. A piece of waterproofing is laid between it and the ceiling if the rack is to rest against a reinforced concrete slab.
• Strut. It is installed, as it should be for braced rafters, at an angle, the size of which is allowed to vary from 45º to 53º. The magnitude of the slope does not play a special role. It is important that the brace itself supports the rafter in the most loaded area. The lower heel of the strut rests on the bed.
• Sprengel. It is a T-shaped short beam of timber, turned upside down. It is used in the construction of large spans that require two or more reinforcing supports. The sprengel is installed so that its base is perpendicular to the rafter. It is located at the bottom of a large span closer to the corner of the roof. Instead of a sprengel, a regular short stance can be used.

They make additional supports again from a double board or bar, installed at the most loaded points.

A video review will acquaint you with the nuances of the support device for the hip roof frame:

The nuances of supporting slanting rafters

The upper heel of the diagonal rafter rests on the ridge run in various ways. The choice of method depends on the design features of the truss system:

• In truss structures with one run along the central axis of the roof, the diagonal rafter legs rest directly on the run consoles.
• In truss systems with two runs and plank rafter legs, the diagonal rafters rest on a truss, which in turn rests on both runs.
• In truss frames with two runs and rafters made of timber, in addition to the sprengel, a surf is used - a short plank that stitches ordinary rafter legs in the ridge area. The thickness of the reinforcing shorty is from 5 cm or more.

The heel of the diagonal rafters for landing on one of the listed upper stops is hemmed in fact. Fastening is done with nails. If necessary, fixation can be strengthened with wire twists or metal clamps.

The lower heels of the braids can rest against the corner of the Mauerlat or a specially installed corner beam. You can just lean on them. Diagonal rafter legs are fastened with metal brackets, nailing over a wooden lining or corners.

Narozhniki and methods of their device

The spears form hips and triangular parts of large slopes. The top of the half-leg rests on the rafter, the lower heel on the mauerlat, mortise beam or wooden floor beam.

Installation of sprockets can be carried out:

• By cutting. In the braids, nests are chosen so that the half-legs of adjacent slopes are not located opposite each other. It is recommended that the distance between the cuts be at least 20 cm. Therefore, in the installation step, the spawners are allowed to move so as not to cut down the nests at one point.
• By installing cranial bars serving as supports for the semi-legs. Bars 50 × 50mm are built up along the lower edges on both sides of the diagonal rafter. Their presence allows you to abandon the cuts, significantly weakening the bearing element.

The second option is easier to work with and is preferable due to the increased rigidity of the structure. In addition, it absolutely does not oblige to change the installation step of the half-rafters: they can be located opposite each other. The sprigs are attached to the Mauerlat or beams in the same way that they used to install ordinary rafters.

Elementary hip truss system

The easiest way to crown a suburban property with a four-slope structure is to buy and install ready-made roof trusses. However, it is much more interesting, more useful, cheaper to do the installation of a hip roof and a truss system suitable for it with your own hands.

Especially if it is planned to build it over a small outbuilding, gazebo or summer kitchen. On simple structures, it is even worth practicing before applying efforts to more responsible objects.

Note that in the example below there is no overlap, the attic is not fenced and there is no insulation. Snow practically does not linger on the slopes, i.e. the rafter legs are subject to the minimum load by their standard standards. The principle of scatter between the spawners has not been preserved.

All nodal connections are made with a nail trap and metal corners. The contractor will need a 5 × 25 cm board for the manufacture of rafter legs and a run, as well as moisture-resistant plywood for the construction of a continuous crate, because the building is planned to be covered with bituminous tiles.

Stage 1: Modeling and design

Regardless of the architectural complexity of the building structure, it needs a project. It will help determine the optimal form and save you from buying unnecessary materials. For a simple hip roof with a standard truss system, super-complex drawings are not required, but at least a simple sketch is necessary.

Instruction for simplified design:

• We measure the width / height / length of the building. According to the data, we draw the profile and full face of the building on a sheet of paper on a scale, for example, 1:50. This means that all dimensions will need to be divided by 50. That is. the wall of the house with dimensions of 5 × 2.5 m on a home-made drawing will be shown as a rectangle with sides of 10 × 5 cm. If it comes out too small, you can choose a larger scale - 1:40, 1:25, etc. It is advisable to duplicate the finished sketch a couple of times in stock.
• We choose the optimal height of the roof and the angle of its steepness. To do this, on one of the duplicates of the sketch, draw several options for the outline of the roof. We determine the most successful and measure the angle of inclination of future slopes with a protractor.
• We mark on the duplicate of the sketch the installation points of the layered rafters, this is a step. We need to divide both walls into equal segments. It is not necessary that the installation step under the hip and pentagonal slope be the same. In the example, the distance between the rafter legs on both walls of the building is 20 inches, which is 50.8 cm. In fact, the installation step can vary from 0.4 to 2.1 m. However, we note that too often installed rafters will significantly increase the consumption of material, and too rarely will force the structure to be reinforced with an additional counter-lattice.
• Decide on the length of the skate. Let's draw it on a duplicate of the template, given that the ridge beam must connect a whole number of pairs of rafters. Set aside equal distances from both edges of the long walls.
• We transfer all the results to the main sheet and calculate how much material is needed. We consider the length of the rafters on the outer sides, taking into account the length of the cornice overhangs of 40-50 cm. Plywood consumption is calculated by the number of solid panels per each plane of a hipped roof.

By the number of rafters, we calculate the number of fasteners. We need nails in literally all nodal fasteners. There should be a pair of corners for each rafter leg. Do not forget to buy a board with a small margin in case of flaws in your own work.

To install a hip roof on brick and foam concrete walls, you will need a bar for the construction of a Mauerlat. It is not needed if the installation of the truss system is carried out on wooden walls.

Stage 2: Construction of the main part of the hip roof

First of all, we will build auxiliary scaffolding on the basis that a full-length home master should be placed between the plane of a home-made stand such as a high bench and a ridge run.

The start of the installation of the truss system for the future hip roof is the installation of the ridge part of the structure:

• We nail to the walls of the building connected with the hips along an auxiliary board, one edge of which should coincide with the central axis. Between the boards we stretch the lace, repeating the central axis.
• We try on a pair of rafters to the end of the building. They should intersect directly under the lace. In fact, we outline the lines of saw cuts of the upper heels, not forgetting that there will be a run 5 cm thick between the rafter legs.
• According to the templates obtained, we prepare layered rafters.
• We install the rafter legs in pairs according to the marks of the main part of the system. Temporarily fasten with one nail.
• We install the ridge run between the upper heels, which previously freely leaned against each other.
• We nail the rafters to the run.
• We attach the bottom of the rafters to the Mauerlat or the upper crown of the house with metal corners.

We dismantle the auxiliary boards, we will no longer need them.

Stage 3: Construction of hip slopes

We fasten the hip part of the rafter system in the same way: the lower heels are cornered to the Mauerlat or to the upper crown, the upper ones are fixed with nails. We work in the following sequence:

• We try on the first slope rafter to the slope, we mark the cut line in fact. The bottom of the rafter must pass exactly through the corner marking point.
• Saw off the marked excess. We nail the diagonal leg to the ridge console, fix the bottom with corners.
• We do the same with the other three braids.
• We fill the hip ramp with sprigs, having previously tried on each detail to the right place and sawed off the excess.
• We install pentagonal ramps.

At the end of the work, the rafters through one are screwed with wire twists to the wooden plugs laid in the walls or to the second crown, so that the structure is not torn off by a strong gust of wind.

There is a way to lay twists of annealed wire into the masonry during the construction process for the subsequent fixation of the truss system. On top of the wire twist there should be three more rows of brickwork or two rows of foam blocks.

A crate is laid on the finished rafter system. In the case of a soft roof, as in the above case, the crate is made solid from inches, plywood or similar plates as a coating. Between the plates or boards leave a gap of 3 mm. For hard materials, the crate is constructed from a bar with the step recommended by the instruction.

Construction of complex hip roofs

The principle of the construction of hip roof frames with a more complex architecture is slightly different from the above example. The sequence of work is exactly the same. True, the layered rafter legs are still more reasonable and more reliable to fix with the help of cuttings.

It is highly desirable to use supports for diagonal rafters. And before mounting the ridge part, support frames are installed with a bed at the bottom and a ridge run at the top. Another change in the angle of inclination of the slopes when supported by a notch should be taken into account at the design stage.

How to build a more complex truss system for an interesting hip roof, see the video:

The hip-type truss system is more complicated than the frame of a conventional gable roof, but you can deal with its device. A four-slope design is preferable in many cases; it looks more interesting both above houses, and above gazebos and other household buildings. The described version of the construction will help to master the basics in the construction of hip structures, and with a successful result, the continuation will certainly follow.

The hip roof belongs to four-pitched structures, the truss system of this type of roof forms four slopes, two of which are connected in the form of a trapezium with their upper faces on a ridge run, and the side slopes form triangles. These triangular slopes are called the hip.

The design of the hip roof has several advantages:

• Convenience for creating an attic floor;
• Profitability (in terms of the consumption of building materials);
• Interesting appearance.

At the same time, the arrangement of this type of roof is fraught with a number of difficulties and requires special calculations when planning the rafter system.

In this article

Features of the truss system

The hip roof truss system involves a number of distinctive elements that determine its distinctive design. Knowledge of these features is necessary for carrying out calculations of the truss system and its construction.

Types of hip roof rafters

The rafters in the design of the hip roof are divided into several types:

• Corner rafters. With one edge they stand on the Mauerlat, with the other they should lean on one of the ends of the ridge beam.
• In a symmetrical hip roof, there are 4 corner rafters that form a hip. Corner rafters are the longest and therefore often need to be strengthened and supported;
• The central rafters are mounted on the Mauerlat and the edge of the ridge run. The scheme of this roof involves 4 such elements, a pair for each trapezoidal roof slope;
• The central hip rafter legs divide the roof hips into two equal parts. The device of the hip roof truss system implies the presence of 2 similar elements.
• Intermediate rafter legs are similar to the central ones and are mounted to the same support points. Their number varies depending on the size of the roof and the length of the ridge. If the roof is small, they may be absent.
• Shortened rafter legs take their place in the corners of the roof. Relying on the mauerlat and corner rafters, they are smaller in size compared to other rafters in size, which becomes smaller towards the corner.

System amplification elements

The hip roof is a complex roofing structure, its truss system needs special reinforcement. The elements responsible for the strength of the roofing object are divided into several types:

• Long corner rafters require special reinforcement. Their strengthening is possible with a sprengel - a corner beam, which represents an inverted letter "T" and the lower part is installed on the Mauerlat, and the upper part rests on the corner rafter. Diagonal rafter legs can be supported by struts supported by floor beams or a central beam;
• Puffs hold pairs of rafters together. They can additionally carry the function of floor beams or be placed closer to the ridge and be the basis for the formation of the attic ceiling;
• Racks strengthen the ridge beam. The lower support of the racks can be a bed if there is a main wall in the center of the building for laying it, or they can be installed on floor beams;
• With a length of intermediate rafters of more than 4 m, they are also reinforced with diagonal posts at an angle of 45-60 ° with the support of the rafters on the floor beams;
• When building a roof in a region with a strong wind load, it is advisable to use a wind support, which is stuffed to the rafters from the side of the greatest wind blow.

Calculation of the truss system

The installation of the hip truss system should begin with calculations of the design parameters and the drawing. The main goal of this event is to select the right materials that can bear the weight of all materials, the load of wind and precipitation. The main quantities that you need to know to build a hip roof are the angle of the slopes and the height of the roof ridge.

Calculation of the angle of inclination of the slopes and the height of the ridge

The angle of inclination of the roof truss system can be in the range of 20-60 °. However, an angle less than 35° will not allow creating a room with a sufficient ceiling height under the roof. Therefore, a roof slope of 20-35 ° is suitable for outbuildings.

Roofs of residential buildings should be arranged at an angle of 40-60 °. The choice of a specific value depends on the weather conditions of the region. In snowy winters, it is better to choose a sharper design - the snow from its slopes will be better off. With large wind loads, it is better to make the roof more gentle to avoid turning it over.

The greater the angle of inclination of the roof, the more complex its scheme and the greater the consumption of materials for its construction.

The calculation of the angle of inclination and the height of the ridge, which are directly dependent on each other, is possible in two ways:

• If the angle of inclination is selected in advance: the height of the ridge is calculated as the value of the tangent of the angle multiplied by half the width of the roof;
• Given the height of the ridge beam: the angle of inclination is equal to the height of the ridge multiplied by 2 and divided by the width of the building.

Rafter length

The dimensions of all types of rafters are calculated using the Pythagorean theorem: the square of the hypotenuse is equal to the sum of the squares of the legs. It remains to figure out which values ​​​​of the elements of the truss system in each case will be the legs, and which ones will be the hypotenuse.

• The central rafters act as a hypotenuse in a triangle with legs equal to the height of the ridge beam and half the width of the roof. Intermediate rafters located on a trapezoidal slope have the same length;
• The size of the central hip rafters depends on the location of the ridge. As a rule, the ridge is equidistant from all three walls;
• To find the length of the corner rafter legs, it is necessary to choose a triangle in which this element is the hypotenuse, and the legs are the central hip rafter leg and half the size of the roof;
• To calculate the length of shortened rafters, you need to know the pitch of the rafters.

Calculation of the pitch of the truss system

The distance between the rafters depends on the width of the house and the plans for the roof space.

The longer the rafter legs, the shorter the step.

When planning a warm room, the step of the system will depend on the selected insulation, as it comes in certain sizes:

• Mineral wool implies a distance of 58 cm;
• Expanded polystyrene requires a step of 60 cm;
• Polyurethane foam can be used with any stride.

The choice of pitch is also influenced by the presence of skylights: the distance between the rafters should be 5-6 cm more than the width of the window opening.

Choice of section of rafters

Depending on the data obtained, the material for the rafters is selected. In any case, it is preferable to choose boards and beams from coniferous trees, with a moisture content of not more than 22%, without knots and cracks. All wooden elements of the future roof must be treated with a special antiseptic to protect the wood from rot and pests.

The cross section of the rafters depends on the distance between them and the length of the spans. We give general information calculated for a step of 90 cm:

• The length of the rafter leg is less than 3 m - section 50 * 150 mm;
• Less than 4 m - 50 * 200 mm;
• Less than 5 m - 75 * 175 mm;
• Less than 6 m - 75 * 200 mm.

As the step increases, these values ​​will increase. All reinforcing elements are always taken with a larger section. Corner rafters are made double, as they carry a much greater load than the rest.

Roof area

When creating a roof scheme, it also requires taking into account the area of ​​\u200b\u200bthe roof and the weight of the roofing material. The area of ​​the hip structure is made up of the areas of its simple figures (triangle and trapezium). To calculate the area of ​​the latter, it is more convenient to break it into its component parts (a square or a rectangle and triangles adjoining it).

The calculation of the areas of figures occurs according to simple geometric formulas: the area of ​​\u200b\u200bthe triangle as half the base multiplied by the height of the figure, the area of ​​\u200b\u200bthe rectangle as the product of its two sides. Since the dimensions of all elements of the system have already been found, this step will not cause any difficulties.

The area data will allow you to buy the required amount of roofing material (do not forget to add 15% to the resulting number for the stock) and the weight of the roof. The sections of the elements of the truss structure will also depend on the latter value.

roof sketch

Before proceeding with the installation of the roof structure, we recommend that you sketch it to scale. This sketch will be a kind of layout and instructions for creating a hip roof:

• We draw a house in two projections (full face and profile) observing all proportions on a scale;
• We mark the height of the ridge and the selected angle of the slopes on the full-face projection;
• We determine the length of the ridge run on the projection of the house in profile;
• On the diagrams, we apply the step of the rafters, draw all the rafter legs;
• We supplement the sketch with the necessary marks for the reinforcing elements of the system.

This sketch will not only help visualize the future roof, but will also become a kind of instruction for its construction. In addition, this drawing will help determine the required amount of building materials.

Complex hip roof

Schemes of complex hip structures, providing for the presence of additional elements such as skylights or bay windows, do not differ much from the one presented above. The basic calculations and the procedure for the formation of the truss structure remain the same.

If there are dormer windows in the hip roof, it is important to take into account the pitch of the truss system and subtract the area of ​​the windows from the total area. When creating a roof with a bay window, that is, a roof over an extension, a tower to a house, a hip structure is docked with some other one: gable, tent, etc. To do this, the necessary additions are made to the rafter system in the form of additional supports for this extension.

Any complex multi-component roof is designed and installed as a combination of simple elements, and this case is no exception. All additional elements of connections to the hip roof must be calculated separately and included in the general plan.

The design of the hip roof in its design is based on rather complex calculations. The success in its construction and operational characteristics depend on their accuracy. Therefore, it is so important not to neglect the creation of diagrams and drawings when referring to this type of roof.

This version of the roof has four slopes. Two of its long inclined surfaces are trapezoidal in shape, and the other two, smaller ones, are in the shape of a triangle - they are called hips. They are located along the gables of the building and connect the ridge with the cornice. Trapezoidal planes have a large area and a slope, also located from the upper horizontal edge to the eaves.

The hip roof has several different designs:

1. Traditional with two trapezoid-shaped slopes and two hips, it is called the "Dutch" roof.
2. Tent - has the same size slopes of a triangular shape. Ideal for square buildings.
3. Semi-hip - hips cover only the upper part of the butt no more than to the middle. Suitable for the construction of houses with an attic, it is called the "Scandinavian" roof.
4. Half-hip - the hips do not have a triangular shape, but are the shape of small trapeziums. Such a roof gives a large attic room, it is also called the "Danish" roof.

Like any other type, the hip type of roof has a frame and a truss system - the whole structure rests on them.

The device of the truss system

The rafter system is the main component of the entire roof structure.

Unlike a gable roof, the device for the supporting structure of a hip-type roof is more complex.

Regardless of whether the building is rectangular or square, the shape of the slopes will not change.

Considering the device of the hip roof rafter system, it can be determined that it consists of several elements:

1. Mauerlat - the basis for the rafters, the link between the bearing walls and the truss system.
2. Skew or diagonal supports - have the greatest length and carry the greatest load.
3. Central rafters - serve to connect the ridge with the Mauerlat on the sides of the slopes, converge at the corners of the ridge from 3 sides.
4. Intermediate rafters - connect the ridge and the eaves.
5. Struts - create not only rigidity, but also provide confrontation with wind loads from the gables of the building, located at different angles to the rafter legs.
6. Narozhniki - the shortest rafters.
7. Sprengel or sprengel trusses - enhance the bearing capacity of the roof structure. They are a beam of timber, located at the corner of the connecting external walls.
8. Racks - give the legs of the supports additional stability, they are installed at the junction of two rafters and a ridge beam.
9. Corner rafter (rib) - located at a smaller angle than the intermediate elements of the system.
10. Short rafter legs - fixed on the corner support board.
11. Skate.
12. Tightening - performs the function of a floor beam.
13. Wind beam - mounted with an inclination on the windy side of the roof.
14. Runs - the distance between the connection of the supports to the ridge.

Installation of rafters

After the type of roof is determined, all the necessary building materials are purchased, you can directly proceed to the construction of the frame.

Before starting the construction of the supporting structure, it is necessary to draw up its project and drawing.

So, the device of the support system consists of several stages:

1. Before starting construction, a wooden beam should be laid along the perimeter of the outer wall - Mauerlat. For its laying, it is necessary to equip a reinforced belt made of reinforced concrete structures that enhance the bearing capacity of the walls. It should be noted that the Mauerlat is securely fixed, preventing the slightest displacement.
2. If the walls are made of stone or brick, a formwork is erected on top of them, into which the reinforcement frame is mounted using galvanized threaded studs, with a caliber of at least 10 mm. The upper part of the studs should protrude 4-5 cm from the base for the supports (Mauerlat).
3. After the frame is installed, the cement mortar is poured.
4. Then, as the concrete hardens, its surface is covered with bitumen and covered with a layer of roofing material or other waterproofing materials.
5. Bars with drilled holes are put on the protruding part of the studs. Fix the structure with nuts.
6. Mauerlat is made from a wooden bar of needles 10 * 15 or 15 * 15 cm dried and impregnated with anti-corrosion and anti-flammable agents. The moisture content of the tree should not exceed 20%.
7. The next step is to install the central beam on the Mauerlat, which is parallel to the ridge. Racks are attached to it. These racks serve as support for a specific part of the support system.

Starting work, it is necessary to check and double-check everything in stages. This is the only way to protect yourself from mistakes and ultimately achieve the most durable design.

Types of hip roof rafters

Hip-type roof supports are divided into two types:

1. Hanging - the beams are located on the beam of the ceiling of the two external walls without additional support.
2. Layered - along the upper edge of the inner walls there is a horizontal beam, to which vertical supports are attached. The basis for the end part of the timber are the outer walls.

The layered type of supports is suitable for buildings with an intermediate supporting wall or columns.

This supporting structure has more base points, so it can be made much easier.

If the building has two load-bearing walls, a screed is installed to support the rafter legs and distribute the load across all vertical supports.

For a hip type of roof, a layered system is considered the most suitable, which gives greater strength and facilitates the construction of the roof.

This modification is used in the construction of an attic or mansard roof.

How to calculate the hip roof rafter system

The calculation of the supporting structure is the main stage in the design of the roof. The slightest miscalculation in the calculations can cause deformation or destruction of the roof.

After studying the roof structure, it is necessary to calculate the angle of inclination of the rafter system. The higher it is, the more the roof is exposed to winds, but it is cleared of snow and ice on its own.

The angle of inclination of the slopes can be 5-60 degrees, it depends on the load of wind and snow.

After determining the angle of inclination, calculations should begin to determine the main loads to which the roof is subject. These include the weight of the roof itself and natural phenomena - wind and precipitation.

The total value of the weight of the supporting structure, lathing, coating and insulation is divided by the area of ​​​​all inclined planes. The resulting value shows the load per 1 m2 of the roof. For a residential building, it must withstand a load of 45-50 kg / m2. This figure is the same for any area.

Sedimentary loads vary depending on the area and amount to 80-150 kg/m2. This value can be found using the "Building Norms and Rules".

The load value must be multiplied by the correction factor:

1. By 1.0 when the tilt angle does not exceed 25 degrees;
2. By 0.7 if the angle value is 25-60 degrees.

If the roof is subject to regular heavy snowfalls, the installation of double supports or continuous battens is recommended.

The determination of the wind load involves the use of the wind pressure coefficient.

The load indicator (wind and snow) is multiplied by an index equal to the value of the rafter pitch. The pitch of the rafters is determined in meters.

The final stage is the calculation of the quantity and criteria of materials.

After calculating all the loads per 1 m2 and on the area of ​​​​the entire roof, the cross section of the supports is determined (the smallest values):

1. Mauerlat - 10 * 10 cm.
2. Puffs and runs - 5 * 15 cm.
3. Filly, struts, crossbars - 10 * 10, 15 * 15 cm.

The number of beams on which the crate is attached and additional elements is calculated by the length of the roof. For example, the length of the roof is 12 m, the step between the rafters is 1 m. Based on this, you will need 24 building legs, 12 on each side.

When carrying out calculations for large-scale projects, it is recommended to use special computer programs for design.

All obtained indicators must be applied to the drawing.

Knots

Accurately calculated knots make it possible to achieve strength and an attractive appearance of the roof.

The connection of elements of roof structures is made according to certain requirements.

The main nodes of the supporting structure:

• ridge knot - a pair of supports is fastened with nails or bolts, and reinforced with bolted beams;
• beam support unit on the Mauerlat - reinforced with metal corners, building brackets, nails or bolts;
• the rafter connection node with a puff, which is located in the middle of the rafter - is carried out using nails or bolts;
• the combination of the brace, rack and support is carried out using die-cutting and reinforced with building brackets.

truss system

The quality of the roof directly depends on the frame and the basis for the roofing. The supporting structure of the roof serves as the foundation and determines its service life.

Rafter system of the mansard hip roof

This support system is resistant to strong wind loads due to the absence of a roof facade wall.

The roof of this form makes it possible to build large plumb lines that protect the walls and foundation of the house from rain, snow and ice.

The constituent elements of the mansard roof rafter system:

1. Mauerlat.
2. Skate and side runs.
3. Support beams.
4. Overhead and hanging rafters.
5. Struts.
6. Support racks.
7. Diagonal rafters.

A distinctive feature of the mansard hip roof is the use of layered and hanging rafters in its design. The upper slope is made from hanging rafters, based on racks or side girder.

To avoid bending, they are equipped with puffs. When installing the lower slope, layered rafters are used with a base on the Mauerlat, and a horizontal beam connecting the rafter system in its middle part.

The lower sloping surfaces have an angle of inclination of about 60 degrees, and the upper ones - at least 30 degrees.

Strengthening the truss system

To ensure the strength and durability of the hip roof, it is not enough to make a truss system, it must also be strengthened.

The most common amplification methods are:

1. Installation of truss bars on the corners of the roof with a stand supporting the diagonal support. If the truss is located far from the corner, it is best to attach a truss truss to it.
2. Installation of racks connected from above with a bar to the ceiling (reinforced concrete) or tightening. They perform the functions of props and ensure an even distribution of the load on the house.
3. The use of double beams instead of a single beam with an excessive length of diagonal rafters.
4. The use of wooden boards 40 * 40 or 50 * 50 mm for the construction of the crate.