Attic Subfloor Thickness

Purchase half inch 1 27 cm thick plywood to act as your flooring.

Attic subfloor thickness.

There are several good t g underlayment brands out there but t g may be a little over kill for your application. Joist dimensions are only part of the equation. For the small difference is cost use 3 4 inch sheathing or underlayment. A subfloor is a stiff wood underlayment secured directly the the flooring joists.

Attic joists that are made from 2x8s may be acceptable for building your attic floor but because every room is variable there are no absolutes. It provides a stable surface for finished flooring material such as laminate. The decision regarding the thickness of plywood to use for the subfloor in the attic has a lot to do with how you intend to use the attic and it also depends on the spacing of the ceiling joists. How to build a subfloor in an attic.

Covering part or all of the ceiling joists in the attic is a cheap way to make use of wasted space. The difficulty comes from the precise measurement and cutting required and the labor of getting the sheets of underlayment in place. You also need to ensure that the joist spacing is adequate. You ll need to make sure that the plywood can fit through your attic door.

Simple sheathing cdx or underlayment should work fine. Take the measurements for your subfloor and measure enough plywood so that you can cover the entire frame. Attic joists for live loads.