Drainage Plane Behind Vinyl Siding

Above the window is the same deal water can drain out air can flow in.

Drainage plane behind vinyl siding. Siding is applied directly over the drainage mat so water can drain out and air can flow in. Which is like the top of the wall. Drainage planes building paper house wrap etc allow any moisture that does accumulate behind siding a chance to drain away harmlessly. Rainscreen between flat to wall siding and the water resistive barrier as a best practice.

With vinyl and aluminum siding the drainage space is more pronounced and furring is not necessary. Since you have tyvek you re all set. The air space between siding and sheathing should also allow humid air to escape. Ideally wood siding should be installed over furring creating a drained and vented air space between the drainage plane and wood siding.

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. Below the window air can flow up and out behind a notch in the trim board. 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. It makes its own drainage gap.

So why use a drainage mat product behind your stucco cultured stone man made stone thin brick hardboard siding or other veneer. There are lots of products and methods on the market today for creating drainage planes. Ideally wood siding should be installed over furring creating a drained and vented air space between the drainage plane and wood siding. Walls that dry are walls that last for a long long time.

With wood siding the drainage space is typically intermittent and depends largely on the profile of the 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. However none of these products does a great job at draining water out from behind the siding materials or allowing the back side of siding to dry out.

Behind vinyl siding you definitely need a water resistant barrier wrb.