Unvented Sip Roof

The 2012 irc permits unvented roof assemblies including unvented sips.

Unvented sip roof.

According to the builder s guide to structural insulated panels sips published by building science corporation the typical reduction of shingle life over an unvented sip roof assembly is between one and two years. These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck. Need to make a final decision on which underlayment to use under a metal roof on an unvented roof system. Integrated sheathing and roof deck for a one stop roof framing product.

This receptor is an air space that can be accomplished in a variety of ways. Venting at the ridge and eave allows air to move freely between the two layers of sheathing. Sip roofs have extreme advantages over traditional framed roofs. With an unvented sip roof the argument would be that the exterior osb facing constitutes the structural sheathing referred to in the code.

Un vented roofs operate on the principle that moisture entering the roof assembly can be controlled and that there is no need for venting to control moisture accumulation. This document provides a brief description of different types of unvented roof assemblies and the benefits of unvented roof construction. With tribuilt granulated self adhering underlayment on top of the plywood. 3 8 plywood diaphragm seams taped.

Create a cold roof by applying a layer of sheathing over 1 3 furring 16 in. Extreme insulation up to r 51. The roof is currently built as follows. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction.

Unvented roof assemblies should be insulated either with air impermeable insulation rigid foam or spray polyurethane foam or with a combination of foam and air permeable insulation. Next i ll be screwing down 5 1 2 raycore sips panels over heated space and framing boxes over the eaves covering everything with 5 8 cdx. Four options for building an unvented roof assembly. This style of roof helps to prevent moisture buildup.

If you don t want to use sips or nailbase there are four basic approaches. Factory engineered and precut per floor plans all but eliminating measuring or cutting material for roof structures. Asphalt shingles store water from dew condensation due to night sky cooling and rain. Beams on 5 centers.

In order for an un vented roof assembly to function properly the following conditions must be in place. Therefore an unvented sip roof is permitted under irc r806 5 unvented attic and unvented enclosed rafter assemblies.