Does Tongue And Groove External Wall Sheathing Have To Be Used?

Exterior wall sheathing has various purposes depending on the type of sheathing used. Structural sheathing is designed to strengthen the walls of a home or building by tying together wall studs, increasing their strength and rigidity. Diagonal tongue and groove sheathing is not very common today, but it was the standard way to sheath an exterior before World War II. The optimal sheathing choice for most homes is Oriented-Strand Board (OSB).

To erect the wall, repairs should be made to level the floor or shim these as needed under each stud. Typically, there’s a 1/8″ gap left between exterior sheathing sheets for expansion. Tongue-and-groove plywood is an engineered wood panel designed to interlock with adjoining pieces, featuring a protruding “tongue” along one side.

When installing shiplap, tongue and groove, or exterior siding, it is important to determine the type of nail gun, length of nails, and board waste. Tongue-and-groove sheathing is not as common today, but it was the standard way to sheath an exterior before World War II.

Tongue and groove plywood is attractive because it would be easy to stack the sheets. Horizontal tongue and groove sheathing should be installed with the groove on the top edge of the boards to encourage surface water run off. If using more local wood materials is important to a project, diagonal board sheathing, like locally milled pine shiplap or tongue and groove, is recommended.

Using tongue and groove sheathing does not replace the requirements of blocking at panel edges in most sheathing thicknesses and products.