The name OSB stands for oriented strand board. In Russian, it sounds like a plate made of oriented chips. They are increasingly used in the construction industry, due to the excellent technical and environmental performance of the material. 90% of the composition is waste from the woodworking industry. The different orientation of the location of the chips in the layers increases the strength, this expands the range of applications of OSB boards. Can this material be laid on the floor?
Technical indicators of plates
For the manufacture of OSB, chips with a length of 60 to 90 mm are used. Their arrangement in the layers is different: if in one the components are parallel to the long side, then in the second they are perpendicular. This is due to the increased strength relative to chipboard and plywood. At the same time, the bending strength is relatively high.
The issue starts with three-layer, and ends with eight-layer elements. Formaldehyde, phenol or polyurethane resins are used as binders. The components pressed under the influence of pressure and elevated temperature are impregnated with waterproof resins and wax. This provides low hygroscopicity, which has expanded the list of works where OSB is used. Therefore, to the question of whether it is possible to lay OSB on the floor, manufacturers answer positively.
The process of creation ensures the evenness of the surface without flaws. Due to the pressure inside, shells and voids do not form, which determines the high quality of workmanship. Sanded panels are used for finishing.
Long chips are a kind of reinforcement. They allow the finished product to withstand high loads.
OSB Security
A large percentage of the composition is a tree. Often, spruce is used for manufacturing, less often pine. Such a composition in itself is harmless. For binders, formaldehydes are used in an amount of 8 to 30 mg per 100 g. masses. In this dosage, they do not pose a danger to the human body. Because the osb slab is laid under the roof, the premises are finished with it. The question immediately disappears whether it is possible to lay this material on the floor. Floors are arranged from it on a concrete screed and on logs. Moreover, in the case of a laminated coating, additional waterproofing is not needed.
According to the flammability class, OSBs are flammable (B3) and highly flammable (G4). When burning, toxic substances and a lot of smoke are released. But when performing work, builders take this feature into account. The surface is lined with a non-combustible coating or a layer that prevents combustion.
Choosing a floor slab
Before buying, you should refer to the following points:
- It is better to purchase products from Canadian or European companies. They use more environmentally friendly components and the quality of their products is higher;
- Products must be certified and meet the E1 environmental safety standard;
- For flooring, it is better to purchase panels of the 3rd category. They are good value for money. For the floor along the lags, it is better to play it safe and purchase type 4 panels. They will cost more, but the floor will be more reliable;
- Models intended for facing and roofing work are not suitable for the floor;
- The choice of coating depends on the purpose of the premises and the composition provided for by the project.
If the installation is carried out on a concrete base, a thickness of 1 cm is enough. If the floor is provided on the bars, it is better to choose a 2-centimeter thickness.
To calculate the amount of material, you need to select the type of product by dimensions. After that, the area of \u200b\u200bthe room and the area of \u200b\u200bone stacked unit are calculated. For clarity, you can expand the elements in the drawing or in a special program. So you can get the number of whole products and chopped.
Cutting is done with an electric saw. When working with a jigsaw, the edges become rough and uneven, which affects the quality of the installation.
OSB will smooth out irregularities and differences in the concrete base. In case of obvious defects, two tiers are laid. For this type of flooring, sheets with a thickness of 8 or 6 mm are used. Laying is carried out with overlapping seams.
It is necessary to lay the elements with gaps for the possibility of expansion from absorbing moisture. This is especially true of not completely dried concrete. The thickness of the gap is from 3 to 5 mm. It is created between the elements and between the wall and the flooring. Fixing to concrete occurs with rubber glue. Before gluing, the concrete surface is treated with a primer to increase the setting. Additionally, the sheets are fixed with driven dowels.
A concrete screed can be laid on top of the OSB. To do this, it is necessary to use products with a waterproof coating. The surface must be rough for better adhesion.
OSB installation will ensure the installation of any finish:
- laminate;
- linoleum;
- carpet;
- tiles, etc.
The characteristics of the plates will increase the sound insulation performance of the base and reduce the thermal conductivity.
From the panels a finishing or draft floor is created. The device process of the first is as follows:
- Logs are arranged in increments equal to the parameters of the OSB sheet;
- A plate is laid on the bars. The joint is on a wooden beam with a gap between the plates;
- The flooring is fixed with self-tapping screws. Fastener pitch 30 cm;
- The second layer is laid with dressing of seams. Fastening takes place with spiral nails. Glue is used for better fixation.
The sequence of work in the draft field:
- Logs are hemmed from below OSB;
- The side of the flooring facing the ground, when installing the base of the first floor, is treated with bituminous waterproofing;
- Insulation is placed in the space between the supporting elements;
- On top of the insulation is waterproofing.
Requirements for slabs when laying different floor finishes
The material is used as an independent fine finish and as a base for various types of flooring. Each installation case has its own characteristics:
- laminate installation. The main thing here is the evenness of the surface. For softer laying, it is desirable to lay a substrate on OSB;
- installation of carpet, linoleum. In this case, the minimum definition of joints is important. Thin sheets are used. Knocks are sealed with sealant;
- osb under the tile. A thickness is selected that can withstand such a load. The product is carefully fixed on the logs, the step of which is less than with other finishes;
- osb plate without coating. Is it possible to lay material on the floor in this form? Yes, but it is necessary to protect the surface with several layers of varnish. The surface of the product in this case must be polished.
OSB can be used in the installation of the floor of almost any design. Their high strength, low moisture absorption and durability will create a reliable and warm base.
OSB or OSB (oriented strand board) is a relatively new building material that has become a successful alternative to plywood and chipboard. The role of OSB in frame construction is great, with the insulation of standard houses. Especially often, with the help of OSB, floor surfaces are formed and leveled. Today we will talk about how to do this correctly.
Types of OSB boards and their characteristics
OSB - boards consisting of several layers of wood chips pressed and glued with waterproof resins. Its gluing is carried out in 3 layers. In the outer layers, the chips are laid along the length of the panel, and inside - perpendicularly. This arrangement gives the OSB strength, allows you to firmly hold the fasteners.
The following types of OSB are used in construction:
- OSB-2 - panels with low moisture resistance. They are used only for interior work in dry rooms.
- OSB-3 is a versatile material. Withstands high humidity both indoors and outdoors. A large margin of safety allows it to be widely used in construction.
- OSB-4 - the most durable and moisture resistant plates. They are used to form load-bearing structures in conditions of high humidity.
For the construction and leveling of floors, OSB-3 sheets are usually used, which perfectly withstand the load from furniture, equipment, and the movement of people.
When leveling small floor defects, it is enough to use OSB boards with a thickness of 10 mm. Surfaces with significant bumps and potholes will require a material of 10-15 mm. If it is necessary to create a floor on logs, then the thickness of the OSB boards used should be at least 15-25 mm.
Wood-based boards, such as plywood and OSB, are widely used for subflooring under the finish coat. Let's compare these two materials in the following article: .
OSB boards are used as an even and solid base for various modern coatings - parquet, tile, linoleum, laminate, carpet. The main functions of oriented strand board are:
- Creating a floor surface. OSB is a popular material for creating a subfloor on logs. In this case, the flooring of the slabs can be carried out both on the upper side of the log and on the lower side.
- Surface leveling. Installing OSB on a wooden or concrete floor will help create a completely flat surface suitable for laying a finishing coat.
- Floor insulation. OSB board is 90% natural wood chips with high thermal insulation properties. Accordingly, the OSB floor does not allow heat to escape and keeps it indoors.
- Noise isolation. The multi-layer dense structure of the OSB reliably absorbs any kind of noise.
Consider several popular technologies for laying OSB on different bases.
Installation of OSB boards on a concrete floor (cement screed)
Let's start with the simplest situation - leveling the concrete base with OSB slabs. Work is carried out according to this scheme.
Debris is swept from the concrete base, dust is removed with a vacuum cleaner. The surface must be absolutely clean to ensure adhesion of the mounting adhesive. The base is covered with a primer. This also contributes to better adhesion of the adhesive to the base. In addition, the primer creates a dense film on the surface, which does not allow the screed to “dust” during operation.
OSB is laid out on the surface, if necessary, trimming is performed with an electric jigsaw or a circular saw. On the wrong side of the OSB, a rubber-based parquet adhesive is applied, using a notched trowel for uniform application. Glue the sheets to the concrete base.
Additionally, OSB is fixed with driven dowels. For guaranteed retention, the dowels are hammered around the perimeter every 20-30 cm. If the floor is even, the installation is carried out in a dry living room, then it is enough to fix the dowels at the corners of each slab (subject to the mandatory use of high-quality glue!).
When laying between the plates, expansion joints with a thickness of 3 mm are left. Along the perimeter of the room, between the OSB and the wall, the seam should be 12 mm. These gaps are necessary to compensate for temperature and humidity expansions (bulges) of the OSB during operation.
At the last stage of work, the OSB base is cleaned of dust and debris. The seams between the wall and the slabs are filled with mounting foam. Its drying time is 3-4 hours. Excess dry foam that protrudes beyond the surface is cut off with a sharp knife.
Installation of OSB boards on boardwalk
Laying OSB on an old wooden floor helps to level the surface and prepare it for the installation of a top coat. Installation is carried out in this way:
- To begin with, with the help of a level or a rule, the localization of irregularities (bulges, depressions) of the boardwalk is determined.
- Boards that “walk” or rise too high above the general level are attracted to the joists with dowels, sinking them into the material. In some cases, to eliminate the creaking and unsteadiness of the boards, the floor has to be sorted out with the replacement (repair) of the lag.
- They clean the influxes of paint from the flooring, bloating and protrusions are washed with a grinder or emery cloth.
- OSB boards are laid out on the floor, with the seams of each next row shifted. Cross-shaped joints should not be! Dilatation gaps are provided (between the plates - 3 mm, along the perimeter of the walls - 12 mm).
- Holes are drilled in the plates. Their diameter should match the diameter of the wood screws that were selected to fix the OSB to the floor. Holes are drilled along the perimeter of the plates every 20-30 cm, countersinking is performed under the caps of the self-tapping screws.
- Self-tapping wood screws attract the OSB to the floor. The recommended length of self-tapping screws is at least 45 mm.
- If you want to make the floor more durable, mount the second layer of OSB. The seams of the overlying and underlying layers should be laid with an offset of 20-30 cm.
- Deformation gaps near the walls are filled with mounting foam, which is cut off after drying.
This completes the process.
Laying OSB on logs on a concrete base
In the presence of a concrete base (for example, floor slabs), the installation of a log and sheathing them with OSB sheets allows you to create a flat floor without the use of wet leveling screeds. And also to fit insulating, moisture and noise insulating materials into the structure.
Consider the technology of creating an OSB floor on logs on an existing concrete base. Logs (wooden bars) are fixed to the concrete floor with dowels or anchors.
The wider the distance between the lags, the thicker the OSB boards used. If the pitch is 40 mm, then the minimum OSB thickness is 15-18 mm, if the pitch is 50 cm - the thickness is 18-22 mm, if 60 cm - 22 mm or more.
Thanks to the lags, space is created between the OSB and the concrete floor. It can be put to good use by laying insulating material. For example, the floors of the first floors are often cold, so a heat insulator can be laid between the joists: mineral wool, polystyrene foam, XPS, etc. If there is a wet basement under the ceiling, the floor structure is supplemented with vapor barrier films or membranes.
OSB boards are laid across the log. The seams between adjacent plates (in width) should go strictly in the middle of the log. During installation, it is recommended to leave expansion gaps (3 mm - between the plates, 12 mm - between the OSB and the wall)
The sheets are fixed to the lags with self-tapping screws or nails (spiral, ring). Step of fasteners: along the perimeter of the sheets - 15 mm, on intermediate (additional) supports - 30 mm. Nails (or self-tapping screws) fixing the plates along the perimeter are placed at a distance of at least 1 cm from the edge (so that the OSB does not crack). Fasteners are selected so that their length is 2.5 times greater than the thickness of the plates used.
How to fasten OSB boards on logs in an ordinary city apartment, see the video:
Creating a subfloor from OSB on logs
Laying OSB on wooden joists is the easiest way to get a durable and reliable subfloor. This technology is especially appropriate with the existing columnar, pile, pile-screw foundation. Work order:
- Logs are mounted on the foundation. The step of the lag should correspond to the thickness of the OSB boards used (the larger the step, the greater the thickness).
- Perform a rough floor roll. To do this, retaining bars are nailed along the lag, OSB boards are laid and fixed on them. The surface facing the ground is covered with waterproofing preparations, for example, bituminous mastic.
- A layer of vapor barrier is laid on top of the OSB.
- Thermal insulation material is laid, for example, foam plastic, mineral wool boards, ecowool, etc.
- Close the insulation with another layer of OSB. Fastening is carried out in the same way as when laying OSB on logs on an existing concrete base (the technology is described in the previous paragraph).
At this point, the work process is considered completed.
OSB processing for different finishes
A strong, hard and even surface makes OSB a universal base for all modern floor finishes. How to cover the floor from OSB? Here are some popular solutions:
- Lacquer or paint. In this case, OSB boards will act as finishing floors, which will only require decorative finishing with paints and varnishes. OSB sheets do not require any additional preparation, it is enough to clean them of dust and apply 2-3 layers of varnish (paint).
- Roll materials - linoleum and carpet. When laying rolled materials, it is necessary to ensure that the joints between OSB boards are flush with the rest of the surface. It is desirable to remove all irregularities with sanding paper. Expansion gaps - fill with elastic sealant.
- Tile(ceramic, vinyl, quartz vinyl, rubber, etc.). In order for the tile to be held on the base of the OSB, it is necessary to ensure its immobility. For this, lags are placed more often than required by the thickness of the sheets. The step between the fastening elements is also reduced. The tiles are glued onto the OSB using a special adhesive suitable for the wood surface and the tile used.
- Laminate- topcoat, which is fixed in a "floating" way, without rigid fastening of the lamellas. This coating is quite rigid, so it is not necessary to prepare OSB for it. Minor irregularities that may be at the joints of the plates are leveled by the substrate.
What exactly to choose - it's up to you.
Using OSB makes it possible to inexpensively and quickly level an existing wood or concrete floor. And if necessary, create it from scratch on the logs. The OSB surface will not require expensive finishing, additional leveling, coating with moisture-resistant compounds. This is an excellent choice for those who want to create a quality floor with minimal effort.
If you decide to replace the old wooden floor and use modern building materials (laminate, parquet, linoleum and others), first of all, you need to get rid of the bumps and cracks of the worn coating. One effective way to solve this problem is to lay OSB on a wooden floor. The ease of use of this material, its quality and relatively low cost have made the plates a popular product in construction.
What is OSB?
OSB (or OSB) - oriented strand board, made by combining wood chips and polymer resins, has several layers (from 3 to 4). The orientation of wood shavings is alternately longitudinal and transverse. This made it possible to improve the physical and mechanical properties of the product in comparison with competitors. You can see the main stages of OSB production in this video:
Reasons for using OSB. Main advantages
- High moisture resistance. The characteristics of this product make it unaffected by the influence of the atmosphere. Even when tested, under conditions of immersion of the material in water for a day, the swelling was 18–26%, while no destruction was detected, and the strength of the plate was preserved;
- Ease of use. Since the product is light in weight, no additional use of lifting mechanisms is required for installation. Absolutely everyone can perform laying work;
- Strength and durability. OSB boards have special properties that can withstand even extreme conditions. In addition, due to the multi-layered product, the material holds any type of fasteners (nail, self-tapping screw, dowel, etc.);
- Low cost. The product has an optimal price-quality ratio;
- Wide range of applications. Plates are used for cladding exterior and interior walls, roof foundations, leveling flooring, and more;
- Environmental friendliness. A quality stove from a reliable manufacturer is 96% natural materials.
How to install OSB on a wooden floor?
To understand this technology, first of all, you need to inspect the old floor. Depending on whether you want to leave the existing coating or dismantle it depends on the procedure.
Installing OSB on existing wood flooring
If your old floor does not creak, does not contain deep and wide holes, there is no fungus and mold, you can safely lay wood-based panels on the existing flooring. However, it is necessary to prepare the floor for further work. It is required to putty cracks and flaws, cut off protruding parts, check the work done using the building level. Only after that you can start laying the slabs.
Attention! In the presence of the listed defects of the existing floor, it is not recommended to lay OSB boards until the defects are eliminated, since the creak from the installation of the new structure will not disappear. Fungus and mold will continue the process of wood decay and decay. In such cases, it is required to dismantle the old coating, leaving the logs, and put a thicker slab.
Having prepared the floor, we begin to lay OSB. We start the process from the most even corner of the room. To ensure a clear fit of the material, you can cut the wood board on one or more sides. Cutting structures should be carried out sequentially, carefully measuring the area of \u200b\u200bthe room and the distance at which it is required to cut grooves and holes for communications, corners, etc.
It must be taken into account that volumetric changes may occur in the material during operation. To prevent the formation of waviness, when mounting the structure, it is shown to leave expansion gaps in the following size:
- gaps between plates 2–3 mm;
- distance from walls 15 mm.
OSB should be fixed with self-tapping screws and nails at a distance of 35–60 cm from each other. The coating will turn out to be of better quality if the material is fixed not only along the perimeter, but also along the diagonal of the product.
Why OSB?
Due to their unique physical and mechanical properties and relatively low cost, OSB boards are becoming more and more common in the construction industry every year. Numerous positive reviews from satisfied builders and customers also contribute to the promotion of this product.
The base for the floors can be made of oriented strand board - OSB. Such boards consist of several layers of large wood chips glued together with resins, and in each layer the chips are oriented perpendicular to the previous one. As a result, high strength of the material is achieved.
Due to the different compositions, processing methods, number of layers, thickness of the chips, quite a variety of OSBs are obtained. It is important to correctly select the right type of OSB for certain conditions for creating floors, and also correctly lay the slabs on the existing base. In turn, the installation method will depend on the surface or installation structure of the floor ...
OSB classification where they are used
There are several types of OSB in terms of resistance to moisture and strength at the same time.
- OSP-2 - are used only inside buildings and only in dry rooms.
- OSP-3 - can be used in wet rooms and outside.
- OSP-4 - they are distinguished by increased strength, they are used for load-bearing structures, as well as in conditions of constant high humidity.
Most often, OSB-3 boards are used in construction. They are also better suited for creating a floor.
The thickness and brand of OSB is indicated in the design documentation.
When building at home, the following rules are usually used.
OSB-2 are used only where there are no variable loads, for wall cladding, interior partitions, furniture ....
OSB-3 boards are used for flooring.
- At the same time, OSB-3 and OSB-4 slabs with a thickness of 10 mm can be laid on even bases.
- If there are potholes larger than 5 cm, then slabs with a thickness of 15–20 mm can be used as a floor base.
- The floor on the logs is created from OSB with a thickness of 15 - 30 mm, depending on the span.
A base made of oriented strand boards can be covered with any floor covering - laminate, parquet, board, linoleum, carpet, PVC boards, as well as ceramic tiles, if the floor construction is sufficiently rigid and does not vibrate.
When deciding on the use of OSB (OSB), it is necessary to pay attention to the environmental friendliness of this batch. In Western countries, OSB is produced with a very low emission of harmful formaldehydes. Due to the release of vapors hazardous to humans, it is now not recommended to use the well-known chipboard and some types of OSB in residential premises.
Due to the danger of formaldehyde emission, the OSB base must be completely and very securely steam-insulated from the living space. Vapor barriers must be designed for such purposes.
How to level a concrete base with OSB
It is not a rare situation when there is a bumpy concrete base, but you need to get a flat surface. Laying the OSB will not be difficult on your own.
If the plates are fastened with a tenon-groove, then it is possible to create a one-piece coating that does not need to be attached to the base. Separately laid slabs do not need to be fixed to the base if the floor covering is not a rigid single structure and is not attached to the subfloor. For example, under laminate, chipboards do not need to be fixed to the base, but under piece parquet, it is better to fix them.
Leveling a concrete base or a cement-sand screed using OSB particle boards is carried out in the following order. The surface is cleaned of dust and primed. Particle boards are prepared, cut to size, immediately for the entire base or for a significant part of the area. The plates are laid out, their position is verified.
Expansion joints 3 mm thick are left between the plates. There is a shift in the seams in the rows. Expansion joints 1-1.5 cm wide are left from the walls to the OSB, into which the foam can be inserted.
Fixing OSB boards to the old floor
An old bumpy plank base can also be leveled with OSB. There are no special differences in work from a concrete base, only fastening will be done with self-tapping screws with a pitch of 30 - 40 cm. For this, holes are drilled in the OSB boards, and reaming is done under the screw heads.
It is important to properly prepare old wood floors for tiling. Separately-bumpy boards need to be pulled to the logs with screws. Try to wedge loose and fastening floorboards from the side of the underground or pull them together with inclined self-tapping screws .... Irregularities, sagging of old paint, can also be removed by grinding or shaving boards.
Laying on lags
The distance between the lags is linked to the thickness of the OSB. It is recommended to make floors with a margin of safety for vibration and deflection. The following are just the minimum chipboard thicknesses depending on the span between the joists:
- 400 mm - 18 mm
- 500 mm - 22 mm
- 600 mm - 25 mm
Usually, the span between the lags is chosen at 600 mm - according to the standard width of the insulation, while the distance between the centers of the lag can be 75 cm with their own width of 15 cm. The floors will be strong if OSB 27 - 30 mm thick is used in this case. 
The most common size of OSB sheets is 1250 x 2500 (mm).
The seams between the plates should be exactly in the center of the lag, while a gap of 3 mm is left between the sheets. Fixing step - 150 - 200 mm, the screw should not be closer than 1 cm to the edge of the plate. Holes are drilled under the screws, countersinking so that the hats are recessed.
The logs themselves can be based on a strip, column foundation, or a combination of them. Also, wooden logs can be laid on a solid concrete floor and attached to it with anchors. The position of the lag is adjusted according to the level.
The use of heaters
The use of logs allows you to place a heater between them, while the following must be ensured.
From the underground (concrete base), the insulation layer is protected by a vapor barrier membrane. A ventilation gap of at least 2 cm high must be left above the insulation. (The reverse placement is also possible - from below the insulation is left open, laid on a solid wooden flooring between the logs, and from above it is closed with a vapor barrier membrane, which is attached to the sidewalls of the log).
The appropriate foam thickness for the temperate climate zone, if the ventilated underground is insulated, is 12 cm, and if mineral wool is used, this value will already be 15 cm. Above open passages, these values \u200b\u200bincrease by 15%.
Oriented strand board OSB can also be laid without a lag on a layer of extruded polystyrene foam, which in turn is laid on a leveled concrete base or on a wooden deck. But at the same time, only OSB fastened with a tenon-groove can be used, since the flooring will not be attached to the base. The evenness of the laying will depend only on the evenness of the base.
It is also possible to lay OSB boards fastened together on top of a bulk layer of expanded clay. But this material should only be placed on a vapor barrier, as it perfectly accumulates moisture. The usual thickness of the expanded clay layer is 30 - 35 cm.
As you can see, leveling floors with OSB and creating OSB bases is not difficult.
To work with them, you need at least a jigsaw, but for large volumes it is better to get a circular saw.
