Most local codes allow OSB to be used for subflooring. It’s always best to check with your local permitting office before using OSB for your subfloor. One advantage that OSB has over plywood is its larger formatting. For plywood, 8-foot and 10-foot long sheets of plywood are standard.

Can you use sheathing as subfloor?

Like Sturd-I-Floor, Rated Sheathing may be plywood or OSB. When used as a subfloor, Rated Sheathing typically requires installation of an additional layer of underlayment on top of it before finish flooring can be applied. The underlayment requirements vary depending on the finish flooring.

Is half inch OSB good for subfloor?

The minimum thickness of plywood for subflooring is about 5/8 inch. Since it does not hold fasteners as well as plywood, OSB must be a little thicker, or at least 23/32 inch.

Is it better to use OSB or plywood for subfloor?

The National Tile Contractors Association and the Resilient Floor Covering Institute both recommend plywood for subflooring and underlayment, because it doesn’t have the risk of swollen edges that OSB does. Plywood also has a slight advantage in stiffness, which means that subflooring panels need not be quite as thick.

What is the best wood to use as a subfloor?

Plywood. Plywood is considered the most popular material used for subflooring, it has been used since the 1950s and remains one of the top choices for contractors. Standard plywood works perfectly fine as a subflooring material, but the best option is ¾” tongue-and-groove plywood subflooring.

What type of plywood is best for subfloor?

Cheap and strong makes CDX plywood great for use as a structural panel such as a subfloor. Remember the letter grade of plywood only has to do with cosmetics and not strength. CDX plywood is just as strong as higher grades. CDX is a type of plywood that grades C, D or X.

Which is stronger plywood or OSB?

OSB and plywood offer similar (and sufficient) performance in terms of strength and functionality, though plywood is about 7% stronger. … Plywood will absorb moisture quicker than OSB, but consequently it will also dry quicker.

Does subfloor need to be tongue and groove?

For subflooring, you use tongue and groove plywood. The tongue and groove are only along the 8 foot edges. On the four foot edges, your seams will fall on joist tops, so no need for tongue and groove.

Is OSB board good for flooring?

Use in Ceilings and Floors Its high strength lets you keep panels relatively thin to reduce costs. … When using OSB boards to cover ceilings or floors, tongue-and-groove joints are recommended because they facilitate installation and yield very even, level results.

Which side of OSB subfloor goes up?

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.

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What thickness OSB should be used for flooring?

For decades, 23/32″-thick OSB has been the most commonly used thickness of OSB subflooring. But a simple switch to 7/8″ panels offers several advantages for accommodating a home’s energy efficiency and for ensuring the performance of finish materials and the overall feel of the floor.

Can I use pressure treated plywood as subfloor?

There’s no need to worry about making treated wood safer that is completely covered in other materials and hidden from access, such as subflooring. Pressure treated wood doesn’t release any gases or particulates that could harm you and your family.

What is OSB plywood used for?

OSB is a material with favorable mechanical properties that make it particularly suitable for load-bearing applications in construction. It is now more popular than plywood, commanding 66% of the structural panel market. The most common uses are as sheathing in walls, flooring, and roof decking.

Can you use OSB for bathroom subfloor?

OSB Subflooring Oriented strand board (OSB) is similar to plywood but the structural differences are what set them apart. … However, OSB is known for swelling around the edges when exposed to water. For tile flooring, this can cause bending and cracking, which is why it is discouraged as a subfloor material for tiling.

Is OSB cheaper than plywood?

OSB is less expensive than plywood. To build a typical 2,400-square foot home, OSB may cost $700 less than plywood. OSB is considered by many to be a “green” building material because it can be made from smaller-diameter trees, such as poplars, that are often farmed.

Why is OSB more expensive than plywood?

Oriented Strand Board, or OSB, has long been used as a low-cost alternative to plywood, but the product now fetches a higher price as increased demand and tight supplies lead to delivery delays and elevated construction costs in the United States and Canada.

Does OSB board warp?

When properly installed, OSB is a durable and versatile material. When it takes on moisture and begins to warp however, OSB changes permanently. Not only does it permanently change shape, but its structural strength and permeability change as well.

What is best material for subfloor?

Plywood has been a standard subfloor material since the 1950s and remains the preferred subflooring for many builders. Standard plywood can be used for subfloors, but a better material is 3/4-inch tongue-and-groove plywood subflooring.

Can I use 11mm OSB for flooring?

They are fairly straightforward but each one is fairly specific. The thickness of OSB that you need varies on where it is used in a building. Typically 3/4″(18mm) for floors and 3/8″ (9mm) for walls and 1/2″ (11mm) roof. Also make sure that you get your supporting timbers at the correct spacing.

Is sheathing plywood OK for flooring?

Plywood is not prone to edge swelling like OSB. As you can see, both OSB and plywood sheathing are good options for the construction of structural sub-floors. Both are strong, durable and long-lasting. … 3) Finished flooring (carpet, vinyl, VCT, ceramic tile, engineered wood floors, etc.)

Should you nail or screw subfloor?

Using code-approved screws rather than nails is the best option for avoiding movement. If using nails for subfloor installation, stick with ring-shank nails; smooth nails may withdraw easier, leading to squeaks.

What happens if you install subfloor upside down?

Upside-down Installation: Panels may be sanded on one or both sides. … Installing some panels with the trademark side up may result in a slightly uneven surface. If bulk water is present on the subflooring panels, drill drainage holes or sweep the water off.

Will rain hurt OSB board?

Our OSB is rated “Exposure 1” and that means that it will withstand normal delays in construction. Normal delays and the rain you indicated will not affect the structural properties of the panels. Certainly it would have been better to have covered the roof with a tarp or roofing felt before it rained.

Why is OSB smooth sided?

The smooth side has a better moisture resistance and will ultimately provide better performance against weather. Facing the board smooth side out will maximize its ability to keep moisture out of the structure. It is simple why manufacturers create roughness on OSB boards.

What is the best thickness for subfloor?

The recommended thickness of the plywood subfloor is governed by the spacing of the joists. Some experts suggest that 15/32-inch plywood should be standard if the underlying floor joists are spaced 16 inches apart or less, but slightly thicker 3/4-inch plywood should be used for joists spaced further apart.

Do I need 2 layers of subfloor?

That’s the usual approach. Almost no one puts down double-thick subfloor in residential applications (for cost and handling reasons), and both layers need to be fastened to joists. Only thin underlayment can be fastened just to the subfloor.

How do you waterproof a subfloor?

Caulk any seams where two pieces of plywood are butted together. Dab caulk onto nail or screw heads to seal the potential leak point they provide. Caulk any splits in the wood or any other areas that may provide a point for water to seep under the subfloor.

Is Spruce plywood good for subfloor?

All wood subfloors must meet national and local building code guidelines. 1) PLYWOOD: Use only American Plywood Association (APA) underlayment grade plywood, minimum ¼”thickness. … Manufacturer-certified poplar, birch and spruce plywood underlayment with a fully sanded face and exterior glue can also be used.

Do I need pressure treated wood for floor joists?

Generally, building codes require pressure-treated or naturally durable wood for the following applications: Joists or the bottom of structural floors without joists that are within 18″ of exposed soil. Beams or girders closer than 12″ to exposed soil. … Wood in permanent structures closer than 6″ to soil.

Do floor joists need to be treated?

Where built into solid external walls, joists should be treated with preservative. I-joists and metal web joists should not be built into solid external walls. The support reaction, due to dead and imposed loads on the floor, should not exceed the recommended value specified by the manufacturer.

How do you stagger OSB subfloor?

Staggering a Subfloor When laying the plywood, install a full sheet along one edge of the floor, then start the next row with a half sheet and use a full sheet for the third row. This technique will produce a regular H pattern, which is undesirable for finished flooring but fine for a subfloor.