How To Cut Osb Slab
How to paint OSB indoors, be it a residential building or a summer house in the country? In principle, any formulations will help you paint. You just need to take into account that each material has its own characteristics when used. Consider several options for which paint is better to use:
- OSB boards are made from resins and polymers, so solvent-borne paints will be the best solution. There is no doubt that the adhesion of paints will maintain the maximum level, because the composition will penetrate into the panel.
- Oil paints are a widespread traditional solution. High-quality coating is provided by high viscosity, low absorption. As a result, a reliable layer is formed, protected from any negative factors.
- You can use alkyd enamels, take compounds for wooden bases. The materials penetrate deep enough into the base, but the coating is still durable. Alkyd mixture eliminates the need for varnishing, which means that finishing becomes cheaper.
- OSB is combined with dyes of the water-dispersed group. But, in this case, there is a high probability that the plate will swell after painting under the influence of moisture. This moment is taken into account even at the planning stage.
On: methods of decorative painting of OSB panels.
What are the advantages of painting?
The use of correctly selected paints and varnishes will give the owners of a house sheathed with OSB boards the following advantages:
- Less effort and time when compared with traditional wall decoration;
- The ability to mask the texture if it is created by large enough chips;
- Protection against moisture. The surface does not suffer from deformation, because water does not penetrate inside.
OSB painting for interior decoration is used only for interior decoration, because outside the slabs will experience a serious impact from the environment. The foundation will require more serious protection. This should be remembered by everyone who is interested in how to paint OSB slabs inside houses.
The choice of paint for OSB boards and painting technology
OSB boards are one of the types of wood-based materials that are in demand among builders and finishers. Such slabs are most often used for wall cladding indoors, small buildings in the form of summer houses, as well as for flooring. Since this material itself does not have a presentable appearance, painting the OSB boards indoors is often almost the only option for completing the finishing work. This technology has its own nuances. And before painting the OSB plate inside the house, you need to understand in detail the painting process, find out which paint is best suited for this purpose.
What types are OSB plates?
Oriented strand board (OSB) is a composite type material with chips in the base. It is glued with polymers, adhesives, resins and other similar substances. In the manufacture, waste is taken after processing aspen, but some slabs can be created from other bases. These products are classified into several varieties according to their chemical composition:
- OSB-1. Suitable for decoration where the humidity level is kept to a minimum. There are practically no moisture-proof components in the composition.
- OSB-2. For normal moisture levels.
- OSB-3. Finish option where there is a high probability of large amounts of moisture entering the surface.
- OSB-4. The variety with maximum durability. Best protected from liquids. Such plates are even recommended for use when working with load-bearing surfaces.
Proper preparation greatly affects how high-quality the final staining result will be. The more thorough the preparation, the higher the adhesion of the material and substrate to other surfaces. Then the decorative layer will last much longer.
There are several important rules:
- Painting can be done prior to panel mounting, if applicable. But this option negatively affects the appearance of the structure. Therefore, more often they still process the cladding, the installation of which has already been completed.
- Grinding is carried out carefully on the surface of the slabs. Standard sandpaper works great. This will not only allow masking the very structure of the slab, but get rid of the layer of protection, which often prevents the penetration of the primer into the depths.
Pre-processing is performed in the following sequence:
- We use a putty in order to level the surface of any parts and places where self-tapping screws are attached. Adhesive-oil base. The best choice.
- Inter-slab seams are sealed with a glue-oil mixture. But the boundaries often become visible, remain a little noticeable. Advice from experienced craftsmen. Do not waste time trying to disguise the material, but simply hide the seams themselves with decorative elements.
- When the putty is dry, it must be sanded until the surface is perfectly flat. How can you cover the OSB is a separate question.
The priming process is as follows. Here’s what you can use:
- The easiest option is a water-based varnish for wood surfaces. Acrylic or acrylic-polyurethane compounds are diluted using a 1:10 ratio. Then they are applied to the boards until the impregnation is uniform.
- Alkyd varnish is one of the available alternatives. But for dilution, not water is used, but white spirit or other similar means. Then the painted object will look better.
- A good alternative is the so-called adhesive primers. Such compositions help to create high-quality surface protection from paint.
How to paint OSB? The instruction looks standard for those who have had at least one-time experience with coloring formulations:
- Take a brush of a suitable width to paint the entire perimeter of the primed surface or an individual board. The layer thickness increases at the edges. The paint will still absorb and the protection is improved. You can also use a roller, so the distribution of the composition will be more even.
- The first, base paint layer is made in a small thickness. The main thing is that when laying the paint, the direction is one. When using water-dispersed formulations, it is important that all paint is distributed equally over different places on the surface. It is impossible to completely get rid of the swelling of the OSB-plate. Therefore, it is important that this process remains at least uniform.
- The panels must be thoroughly dried. Inside the room there should be no sudden temperature changes, drafts.
- The second layer is applied at least 8 hours after the completion of the previous stages. The strokes must be applied perpendicular to the previous layers.
- The operation can be repeated until the surface looks appropriate. Buildings are covered with compounds using slightly different technologies.
Painting OSB plates at home is not as difficult as it seems at first glance. Indoors, the material is influenced by a minimum number of environmental factors. Therefore, the outer layer must meet not such serious requirements. But even in such situations, the selection of material becomes of paramount importance, as well as adherence to the work methodology. Therefore, it is important to study the recommendations provided by professionals. It is good if there is an opportunity to study in advance as many tips as possible together with the training, especially if the work is done by a novice master.
How to fix walls to a frame using lathing
When solid slabs are attached to the frame from the inside of the wall, ensuring good rigidity of the wall structure, then a crate can be made from the outside between the frame and the OSB plate. The lathing forms air cavities for ventilation of the insulation and reduces deformation loads from the frame on the OSB board.
Insulation is placed between the frame posts. On top of the racks and insulation, a wind and waterproof membrane is attached, which easily permits moisture. Next, the crate is attached and OSB slabs on it.
Installation of OSB boards on a wooden frame with crate.
With this design, the slabs can be left without finishing, you can paint them, plaster or fix almost any facade material on them.
When fixing OSB boards without using a crate, the maximum rigidity of the wall structure is achieved. In this case, it is recommended to fasten the wind and waterproof membrane behind the OSB plate, then mount the crate to create a ventilation gap and front material on it, such as siding, boards or decorative panels. OSB boards are attached to the wooden frame with nails at least 2.5 times the thickness of the OSB sheet.
The advantage of using nails over self-tapping screws when fixing OSB from the outside of the house is justified by the fact that nails better tolerate deformation of OSB sheets under atmospheric influences.
Fastening OSB boards to a metal frame
Fastening is carried out in the same way as with a wooden frame. When fixing the plates directly to the metal frame, self-tapping screws for metal are used with a length of 10-15 mm more than the thickness of the OSB sheet.
Which side to fix OSB sheets
All sides of OSB sheets do not differ in composition. But there are differences in the surfaces. Often one side is smooth and the other rough. In this case, when installing slabs on walls from the outside of the building, it is better to fix the sheets with the smooth side out. With this orientation, rainwater will not accumulate in such quantities in the unevenness of the slab. Water accelerates the destruction of the slab. Protection of sheets from water penetration into them helps to increase their durability.
When installing slabs on the roof under the roof, in turn, OSB sheets are recommended to be placed with the rough side up so that it is not slippery to walk on them during roofing work.
When installing OSB boards in places protected from moisture, the choice of their orientation does not have a significant effect on subsequent operation.
General rules for mounting OSB plates to the wall
Regardless of the chosen method of fixing OSB sheets, there are general rules, the observance of which will ensure maximum strength, reliability and durability of the sheathing structure.
- Self-tapping screws should be screwed in at a distance of 10-15 cm from each other and at least 1 cm from the edge of the plate.
- A gap of 10 mm is required between the bottom plate and the foundation to prevent water accumulation.
- Plates cannot be joined close to each other, a gap of 2-3 mm is required between them so that the plate can expand freely from moisture changes.
- All door and window openings are cut with a jigsaw or circular saw, but if you need perfectly smooth joints and cuts, then you can come to the furniture shop with ready-made dimensions and OSB sheets, where for a small fee they will saw your sheets on a panel saw exactly and exactly to size.
Fastening OSB slabs to the wall over insulation using lathing
The fixing of the slab to the wall is carried out using a lathing, which is made from a wooden bar, or a metal profile. The technologies for mounting OSB boards on a wall with wooden lathing and metal profile lathing do not fundamentally differ. When choosing a bar, it is advisable to choose a dry, planed bar of 40-50 mm, then it will not turn out and will not lead after drying, which will positively affect the evenness of the entire wall.
To attach the bar and profile to the wall, special metal plates (suspensions) are used. Before fixing the suspensions, it is necessary to draw vertical stripes on the wall, the distance between which should be half the width of the sheet, which, subsequently, will ensure the joint of the slabs right in the middle of the bar or profile and will make it possible to fix the OSB slab in the center along its entire length. After the mowing lines are drawn, hangers are attached along them with a step of 30-40 cm.
The metal hanger is used to fasten the battens. Suspensions are attached to the marked lines. Suspensions allow you to fix the crate over the insulation.
After that, the insulation is laid and covered with a membrane that protects the insulation from moisture, after which the crate is mounted.
It should be noted that vapor barrier is not needed outside the building, since it prevents moist air from entering the insulation from the inside of the room, and from the outside of the building, excess moisture should freely go outside.
Wall with lathing. Insulation is laid between the crate and the wall.
After fixing the lathing, you can proceed with the installation of OSB boards. For wall cladding, a 9 to 12 mm thick slab is most often used. If a facade is not mounted on top of the slab, then the slab must be moisture resistant. OSB boards are fastened to the lathing made of wooden beams with nails at least 2.5 times longer than the thickness of the OSB sheet. To the crate from a metal profile. On self-tapping screws for metal 10-15 mm longer than the thickness of the OSB sheet.
With this installation, the crate weighs over the insulation, and does not create cold bridges in the insulation between the wall and OSB boards. Thanks to this solution, the maximum efficiency of the insulation is achieved. In addition, there is an air gap between the battens of the crate, through which moisture is removed from the insulation, which also increases its characteristics. For more information on ventilated facade technology, see the article: ventilated facades, types of ventilated facades.
Protecting the wall from mice, birds and insects
In most cases, installation of OSB sheets outside the house is provided with a ventilation gap. Air moves along it, which enters from the bottom of the wall from the surrounding space and comes out from above back into the atmosphere. Deaf sealing of ventilation gaps on either side is not permissible. Otherwise, instead of a monosazor, a closed air cavity is obtained.
Wasps, mice, small birds can enter the ventilation gap and build nests there, thereby disrupting the characteristics of the wall. Therefore, it is recommended to provide protection at the stage of its construction or repair.
There are several options for protecting the wall from rodents, birds and insects, consider them.
- Protection with metal mesh and fine-mesh sheet metal. It is better to use stainless steel that will not corrode. The mesh or strips of metal are attached from the bottom and top of the wall behind OSB sheets so that they do not affect the appearance of the house.
- Painting grid. Differs from the previous version in low price and less durability.
- Perforated facade material at the bottom and top of the wall. For example, in the case of siding, these are perforated soffits.
Grilles or nets are mounted at the inlet and outlet of ventilation gaps.
After installing the OSB sheets, you can proceed to the sealing and further finishing. You can find out how to properly seal the gaps, what sealing material and in what cases to choose in a separate article: correct sealing of OSB joints.
OSB boards vary in thickness. It can be 6, 8, 10, 12, 15, 18, 20, 22, 25 mm. The tensile strength of slabs is inversely proportional to their thickness.
- 2440×1220 (Kronospan);
- 2500×1250 (Kronospan, Egger, Krono);
- 2800×1250 (Kronospan).
For OSB boards
The price for OSB depends on the thickness and area of the slab, brand, additional processing. For OSB-3, it varies in the following range:
|Thickness in mm.||Minimum price per sheet||Maximum price per sheet|
|6||237.00 UAH||259.2 UAH|
|8||204.40 UAH||UAH 281.00|
|ten||221.50 UAH||UAH 284.00|
|12||265.40 UAH||343.00 UAH|
|15||340.00 UAH||425.00 UAH|
|18||410.00 UAH||527.05 UAH|
|22||643.70 UAH||643.70 UAH|
Disadvantages of OSB
With its numerous advantages, the oriented strand board is not without some disadvantages. In particular, not all manufacturers use safe polymer binders and comply with environmental regulations. Resins containing formaldehyde and other toxic substances are often used in production, and the emission level may exceed the maximum permissible. Therefore, it is better to buy products from well-known brands that have passed certification. Unlike solid wood, OSB has low vapor permeability, so the enclosing structures do not breathe from it.
What is the thickness of OSB slabs for the floor on the logs
OSB boards serve as a reliable base for flooring. They can be laid on a solid base (concrete or old plank floor) to level, strengthen and insulate it. Often, OSB installation is also carried out on lags. If slabs that are too thin are placed on supports that are far apart from each other, they will sag under load. The larger the step between the lags, the thicker the OSB is required. OSB-3 is suitable for the floor, these boards combine high strength with moisture resistance.
Step between lags, cm
OBS-3 thickness, mm
Important! The table shows averaged data; to obtain more accurate, engineering calculations are required, taking into account a number of additional factors.
Is it possible to attach tiles to the OSB plate
OBS is used as a perfectly flat base for various topcoats. When laying ceramic tiles on OSB plates, you need to take into account the following points:
- OSB is a material with high absorbency, because of this, the consumption of glue increases and the adhesion of the wood board and ceramic tiles deteriorates;
- Oriented strand boards are resilient, flexible enough material, and tiles are very rigid.
To increase the rigidity of the base for the floor covering, it is necessary to reduce the step between the logs (if OSB is mounted on them) to 20-30 cm and use a slab with a thickness of at least 15 mm. When facing walls, you can adhere to the standard scheme (the step between the frame elements is 40-60 cm, the OSB thickness is 12 mm).
There are several ways to improve adhesion (adhesion).
- Prepare the board itself and use wood glue.
- Fasten the reinforcing mesh to the OSB.
- Intermediate cladding with moisture-resistant plasterboard.
The latter option is the most costly and leads to a slight increase in the thickness of the structure, but the tile will be reliably glued. For fixing it, you can use compositions based on gypsum, cement. And the drywall itself is attached to the OSB with self-tapping screws. In the first two cases, you first need to increase the roughness of the slab by treating it with coarse sandpaper. Then, in 2 doses with an interval of at least an hour, the plate is covered with a polymer primer or PVA glue. After 12 hours, after the primer has completely dried, you can start gluing the tiles.
If a metal mesh with cells of 5-10 mm is fixed on the plate prepared in this way, it will be even more reliable. The mesh is fastened with staples or self-tapping screws without sagging and tearing; at the joints, an overlap of several centimeters is made. Even in the case of mesh reinforcement, it is better to choose an adhesive mixture of high elasticity for wooden substrates, for example, Ceresit CM17. For floors that will be exposed to significant stress, a two-component epoxy adhesive is preferable, but it is more expensive.
So, laying ceramic tiles on an OSB slab is possible, but it requires additional labor and materials.
The possibilities of using OSB boards are varied. First of all, this is construction work. They are made and constructed of:
- SIP panels for frame construction, base of thermal panels;
- Continuous roof sheathing;
- Dry floor screed and finishing floor covering;
- Removable formwork;
- Temporary fences.
Waterproof OSB board for outdoor use is used as a facade cladding for painting, plastering or as a rough cladding, on top of which other facing materials are mounted. Plates of the lower class are suitable for the manufacture of containers, load-bearing elements of furniture, inner lining of vehicles.