What's the difference between OSB 2 and 3?

OSB2 is great for structural, non-load bearing projects in dry conditions whereas OSB3 performs better for structural, load bearing use and for use in humid conditions.

What thickness OSB should I use?

The recommended minimum thickness of OSB panels for timber-frame walls is 12mm when the cells in the supporting frame measure up to 62.5cm on a side, and 15mm for frame members spaced up to 83.3cm apart.

What is the difference between OSB 3 and OSB 4?

SMARTPLY OSB4 is approximately 30-35% stronger and 20% more moisture resistant than OSB3 and is therefore a very cost-effective alternative in humid and high-load structural applications to a similar performing exterior structural plywood marked as “EN 636-3 S” (previously “WBP”1).

What does OSB 3 board mean?

The trade term OSB/3 comes from the technical class denoted in BS EN 300 for 'load-bearing boards for use in humid conditions'. Humid in this instance meaning environments where boards are protected from external conditions but moisture content can increase because of humidity.

What type of OSB is used for roofing?

Typical types of wood used for roof sheathing are oriented strand board, known as OSB, and plywood, the most popular being OSB. Sheets of 7/16-inch thick, with no edge support, can be used in an area where the snow load is 30 pounds per square foot. With edge support and the same snow load, 3/8-inch OSB can be used.

Which is better, OSB or Plywood?

What side of OSB goes down on roof?

Answer. OSB roof panels should always be installed with the grade stamp facing into the attic and the screened surface (with the nail guide lines) facing up.

Does it matter which side of OSB goes down?

Using OSB Safely

When installing in vertical applications such as wall sheathing, you'll want to orient the smooth or stamped side facing out. The smooth side has a better moisture resistance and will ultimately provide better performance against weather.

Can OSB 3 board be used outside?

OSB can be used for outside applications. However, those OSB boards are classified as class 3 and they are appropriate for use in humid conditions. Even if you buy OSB that is waterproof from the market, you should apply an additional layer of waterproofing for protecting the board from moisture or water.

Can OSB 3 board get wet?

OSB is manufactured using waterproof resin adhesives that coat all wood strands, making the panel more water-resistant than other panels. The edges are also sealed for further protection when the panels are sized at the mill. OSB is highly water-resistant, but not waterproof.

Are there different OSB grades?

Five grades of OSB are defined in EN 300 in terms of their mechanical performance and relative resistance to moisture: OSB/0 – No added formaldehyde. OSB/1 – General-purpose boards and boards for interior fitments (including furniture) for use in dry conditions. OSB/2 – Load-bearing boards for use in dry conditions.

Is OSB board water proof?

As a general rule, most OSB are water resistant. Due to their construction process using wood strands, resins and wax they come fairly water resistant.

Is OSB stronger than plywood?

Osb is stronger than plywood in shear. Shear values, through its thickness, are about 2 times greater than plywood. This is one of the reasons osb is used for webs of wooden I-joists. However, nail-holding ability controls performance in shear wall applications.

What do you seal OSB board with?

For cases where OSB is more likely to be exposed to moisture, it's a good idea to coat the OSB on the surface and edges with a waterproofing product, such as Thompson Water Seal, Flex Seal, or Liquid Rubber's waterproofing sealant. Even latex paint will work.

How thick should OSB be for garage walls?

Note: IBC & IRC require a minimum thickness of ⅜” for OSB for wall sheathing.

Is it better to use OSB or plywood for subfloor?

OSB has a lower resale value than plywood due to its lower strength. For this reason, few homeowners prefer OSB in their homes. Apart from costs, plywood is superior in all the other areas, such as the strength of the structure. For this reason, it's a superior material for use on the subfloor.

What OSB is used for walls?

Building experts consider oriented strandboard (OSB) and plywood to be equally effective as wall sheathing, roof decking and floor underlayment. Because of the manufacturing process, OSB is less costly and more environmentally sound than plywood. OSB used for wall sheathing should be 7/16 inch thick.

How do you seal OSB edges?

To apply, soak the tip of the paintbrush in the sealer and brush it over the OSB board's ends and surface. Ensure this process is repeated on both sides, and not just the areas where you made cuts. Coat your OSB pieces and allow the seal to dry for 12 to 14 hours. Now turn the wood and coat the remaining surfaces.

Does OSB board warp?

OSB is built by pressing smallers strands of wood together with glue and wax in a hot press. OSB looks a lot like a collage of different wood chips. Unlike it's plywood counterpart, OSB lacks the forces that tend the wood to warp, and so is easier to get perfect dimensions and avoid warping tendencies.

What happens if it rains on OSB?

OSB won't be completely destroyed by water, unlike MDF or similar interior laminate materials; however, like any wood product, it will swell and shrink as it absorbs and releases water, so you should typically avoid more than casual contact with water.

Which lasts longer OSB or plywood?

Plywood and OSB are generally considered to have the same load strength. However, as plywood has been around longer, it has shown that it can last 50 or more years in an installation. OSB does not have the same track record because it has only been marketed for about 30 years.

Will Zip tape stick to OSB?

Most builders assume — and GBA has long reported — that oriented strand board (OSB) is a good air barrier. If a builder uses a high quality tape like Siga Wigluv, Zip System tape, or 3M All Weather flashing tape to seal sheathing seams, OSB wall and roof sheathing can act as a building's primary air barrier.

Can you paint directly onto OSB?

OSB's open strands readily absorb the paint, requiring two or three coats of primer to close up the pores. Older OSB will be incredibly porous, requiring several coats of paint plus primer. Particularly old OSB that is beginning to fall apart cannot be painted; the paint will not help glue the OSB together.

Can I use OSB for roof?

Both OSB and plywood panels can cut and installed on a roof using conventional roofing equipment. They have similar structural characteristics, and can be used interchangeably.