What is tongue and groove plywood?
It is structural plywood milled with a tongue on one edge and a matching groove on the other, so neighbouring sheets interlock. The joint transfers load between panels without a supporting joist under the seam, which reduces movement and squeaks in subfloors, roofs and walls.
Is tongue and groove sheeting better than square-edge plywood?
For flooring it usually performs better. The interlock stiffens the seam between joists, cuts down on edge deflection and helps prevent the bounce and squeaks you can get where square-edge panels meet. Square-edge sheets can match it only if the seams are blocked underneath.
Can tongue and groove plywood be used for wall and roof sheathing?
Yes. Tongue and groove panels are used for roof decking and, less commonly, walls, where the interlocking edge adds shear continuity and a solid fastening line. Follow the panel's span rating and local building code for spacing and thickness; minimum wall sheathing thickness is code-driven, often around 15/32 in for plywood.
What thickness of tongue and groove plywood is used for a subfloor?
23/32 in (nominal 3/4 in) tongue and groove is the common residential subfloor choice over joists at 16 in on centre. Wider spacing calls for a thicker panel or closer support. Always confirm the span rating and follow local code.
Is there tongue and groove OSB?
Yes. Tongue and groove is available in both plywood and OSB (oriented strand board). Both interlock at the panel edges to spread load across the seam; the choice between them comes down to span rating, moisture exposure and local availability rather than the joint itself. Confirm the panel's stamp and span rating for your application.
What are the disadvantages of tongue and groove plywood?
The interlocking edge tends to cost more than square-edge plywood and takes longer to install, since the tongue has to seat fully into the groove on a flat, correctly spaced frame. The milled edge can also chip if it is not protected during handling. On uneven framing the benefit is reduced, so the panel is best matched to well-prepared joists or rafters.
