Unvented Roof Soffit

A properly functioning un vented roof.

Unvented roof soffit.

In an un vented roof foam can serve as the air barrier and vapor retarder and prevent moisture from getting in to the roof cavities. Unvented roofs also. When the house has no soffits and hence no soffit vents. Like a wall that is severely out of plumb an unvented roof has insulation packed into the framing cavities aligned with the sheathing.

This document provides a brief description of different types of unvented roof assemblies and the benefits of unvented roof construction. An unvented roof is often the only viable option when roof framing is complicated such as when there are hips valleys dormers or skylights that would prevent eave to ridge ventilation. Windstorms for example can cause vented soffits to collapse creating excessive pressure which may lead to window blowout and roof loss. These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck.

Item 88997 model xsss25824. Foam and the roof assembly foam insulation can play an important role in both vented and un vented roof assemblies. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction. Smartside 23 938 in x 191 875 in 38 series primed wood vented soffit.

Because the attic space is now inside the thermal envelope blowing a little heat up there is not like throwing twenty dollar bills out the window. Or when adding eave vents would clash with the house s architectural style.