What Kind of Plywood is Good for a Subfloor?

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Plywood is a typical materials for building and it is generally used for subfloors. This text discusses what sort of plywood is finest for subfloors.

A man installing a subfloor using a hammer.

Commonplace plywood is nice for subflooring as a result of it’s low-cost and dependable. A ¾-inch tongue-and-groove plywood subflooring is maybe the very best general materials to make use of as a result of the perimeters interlock, which permit the panels to withstand motion.

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There are various causes a powerful subflooring is vital in your dwelling. In case you use the flawed supplies in your subflooring, your tiles could crack, gaps can open up, or you’ll be able to have a squeaky ground. 

Subflooring is the a part of the home you don’t see however occurs to be one of the crucial vital elements. Whereas choosing the proper tile or wood ground is vital, it might at all times get replaced at a later date. Your subfloor is taken into account everlasting and is hooked up to your private home’s framing.

That can assist you choose the very best plywood in your subflooring, we’ll go over the very best sorts to make use of in your dwelling.

What Kind of Plywood is Good for the Subfloor?

Different type of tiles and plywood piled up.

Two fundamental forms of plywood are perfect for sub-flooring: CDX and Tongue and Groove. Nevertheless, in case you’re doing a DIY venture, it’s vital to learn about and perceive what subflooring is.

Picket, structural subfloors are used to assist the set up of sturdy flooring. Right this moment, plywood is essentially the most used subfloor materials. Plywood is available in all kinds of shapes, sizes, and layouts

Relying on the meant operate, several types of plywood are made with quite a lot of supplies and processes. Plywood subfloors are available quite a lot of varieties.

The thickness of Plywood Subfloors

As a basic rule, a plywood subfloor is made out of sheets of plywood which can be between ¾-inch and ½-inch thick, every with a tough and a clean aspect. 4-by-eight or four-by-twelve foot sheets are the commonest.

Gluing and urgent a number of skinny slices of strong wooden collectively at 90-degree angles leads to a remarkably sturdy structural sheet, which is what is called plywood. Stable wooden planking was swiftly supplanted as a subfloor materials in houses by this product within the Nineteen Fifties.

Subfloors may be made of normal plywood, however tongue-and-and-groove sheets that interlock on the edges are extra frequent. The optimum plywood subfloor thickness is decided by the joist spacing.

For joist spacing of 16 inches or much less, some consultants advocate utilizing 15/32-inch plywood; for joist spacing of greater than 16 inches, ¾-inch plywood should be used. Seek the advice of your native code authority, nevertheless, for essentially the most up-to-date info.

What Determines Subfloor Thickness?

The thickness of plywood required for subflooring is roughly ⅝-inch thick. ‘ OSB should be a minimal of 23/32 inches thick as a result of it doesn’t retain nails in addition to plywood.

The thickness of the subfloor is decided by a number of components, together with the quantity of insulation it gives. All of those elements should be considered as a result of each can limit the thickness of the subfloor.

Dimensions of the Joists

Floor joists made from plywood and OSB.

The space between the ground joists, on which the subfloor rests, is a essential determinant of subfloor thickness. The bigger the space between the joists, the higher the thickness of the subfloor needed for structural functions.

When joists are lower than 16 inches aside, a half-inch of subflooring could suffice. You’ll want a thicker subfloor for stability in older houses with extra dispersed joists. For this venture, 7/8-inch plywood and 1-inch OSB are a should.

The texture of your ground may be vastly influenced by the stiffness of the subflooring. Moreover, it performs a big function in ensuring that your ground stays flat and even. Because of this, you need to select the right subflooring thickness in your dwelling’s building.

Why is that this related? So, whereas denser subflooring may need higher insulation, it might scale back the counter house for underlayment choices. 

Vertical Spacing

The “R-value” of a product’s insulating capability needs to be taken under consideration when figuring out the right thickness of flooring materials. 

Greater R-value constructing supplies are higher at maintaining the warmth in throughout winter and maintaining it out by means of the summer season, respectively. R-values vary from one of many biggest — for wool carpeting — to one of many lowest — for skinny, engineered wooden.

Subflooring is identical. OSB has a better R-value per inch (2.0) than plywood (1.1). (1.4 per inch). Because of this, whereas structurally thinner plywood could also be acceptable, its insulating qualities shall be inferior to that of OSB of the identical depth.

It is a essential issue to bear in mind, particularly if there’s a little hole between your ground and the slab or crawlspace. As a basic rule, in case you’re coping with a narrower vertical house, you’ll wish to use a product with a higher R-value.

Subflooring Plywood Choices


CDX plywood is essentially the most usually used subflooring plywood. The roughness of the outer layer is graded from C to X. On account of its location in an space of the home that’s hardly ever seen, a better grade of flooring isn’t needed.

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Imperfections and roughness are frequent traits of CDX plywood. Because of this, shopping for by the sheet is considerably extra inexpensive. It’s a preferred alternative for householders as a result of it’s cheap and strong.

Plywood letter grades are primarily based on look solely, not on general high quality. The energy of CDX plywood is on par with that of upper grades. It may be used for exterior sheathing in the identical method as OSB. Nevertheless, it’s much less water resistant.

Tongue and Groove

A man attaching two wooden plank using a wood glue.

T and G is a type of woodworking joint often called “tongue and groove” or “T and G.” It’s like a mortise and tenon in look. 

The plywood has a protruding ridge that slides right into a groove within the adjoining edge. OSB (a plywood substitute) and CDX subfloors can be found in tongue and groove kind.

It’s good for subflooring because it stops the plywood’s edges from shifting and squeaking after the insulation has been put in. Tongue-and-groove joints may be sealed extra successfully with building glue. 

Essential Various to Plywood

Subflooring Oriented Strand Board (OSB), or OSB, is among the many mostly used options to plywood.

Picket and structural subfloors are used to assist the set up of sturdy flooring. Right this moment, plywood is essentially the most used subfloor materials. Plywood is available in all kinds of shapes, sizes, and layouts.

Based mostly on the goal operate, several types of plywood are made with quite a lot of supplies and processes. Plywood subfloors are available quite a lot of varieties.

Strategies for Putting in a Plywood Subfloor

A man installing a wooden plank on the floor.

Putting in engineered or strong wooden on a plywood subfloor with hid nailing is the commonest and most popular technique. Nailing down both sort of ground sometimes requires a thickness of at the very least 18mm, and staples or cleats are usually advisable for something lower than 18mm. 

A minimal of 50mm in size is required for nails or staples used to lock wooden flooring to the subfloor. Flooring planks may be nailed down instantly on prime of the plywood with this size. Test for service pipes earlier than stapling or nailing something down.

Subsequent, you’ll want to use glue to your ground. A ground adhesive can be utilized to connect each common and engineered wooden to a plywood subfloor. Wooden glue and ground adhesive are two distinct issues that shouldn’t be combined.

Lastly, there’s floatation. Floating engineered wooden flooring is essentially the most easy technique of set up. It’s needed to connect the tongue and groove connections of the floorboards collectively after they’ve been flippantly laid over the underlay.

When is Multilayer Subflooring Wanted? 

Subfloors are sometimes 5/8-inch thick or extra in new building. One other frequent thickness is 7/8 inch, and a number of other subfloors are rather more substantial. In new building, multilayer subfloors are usually not used, though they’re utilized in retrofits.

Utilizing building adhesive to connect CDX plywood to the earlier ground after which nailing it down will take away a lot of the spring and creaks from a house with thinner joists with bouncy flooring, usually often called ground deflection. When putting in one other layer of plywood on prime of the unique plywood or strong wooden ground, it’s finest to go together with a thinner layer.