Drainage Plane Behind Siding

After the windows are installed add a mesh drainage mat to the outside the wall.

Drainage plane behind siding.

One of the first things that a good builder learns early in their career is the fact that all siding. A 1 inch air gap is needed behind brick veneer as required by the 2009 international residential code irc baechler et al. Building america recommends a gap of at least 1 16 inch behind lap siding and a drainage space of inch between stucco and plastic house wraps to control liquid phase water penetration. You don t need a separate air gap between the vinyl siding and the tyvek because vinyl siding is installed loosely and doesn t sit tight to the sheathing.

Above the window is the same deal water can drain out air can flow in. Ideally wood siding should be installed over furring creating a drained and vented air space between the drainage plane and wood siding. There s probably some truth. This space is known scientifically as a drainage plane and it is most effectively created by installing a product commonly referred to in the industry as a drainage mat.

Drainage planes are water repellent materials building paper house wrap sheet membranes etc that are located behind the cladding and are designed and constructed to drain water that passes through the cladding. Since you have tyvek you re all set. Old timers will tell you there s no substitute for using tar paper under siding. With vinyl and aluminum siding the drainage space is more pronounced and furring is not necessary.

Below the window air can flow up and out behind a notch in the trim board. It makes its own drainage gap. Siding is applied directly over the drainage mat so water can drain out and air can flow in. Behind vinyl siding you definitely need a water resistant barrier wrb.

So why use a drainage mat product behind your stucco cultured stone man made stone thin brick hardboard siding or other veneer.