Unvented Sip Roof

3 8 plywood diaphragm seams taped.

Unvented sip roof.

In order for an un vented roof assembly to function properly the following conditions must be in place. Need to make a final decision on which underlayment to use under a metal roof on an unvented roof system. This receptor is an air space that can be accomplished in a variety of ways. This document provides a brief description of different types of unvented roof assemblies and the benefits of unvented roof construction.

This style of roof helps to prevent moisture buildup. With an unvented sip roof the argument would be that the exterior osb facing constitutes the structural sheathing referred to in the code. 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. Therefore an unvented sip roof is permitted under irc r806 5 unvented attic and unvented enclosed rafter assemblies.

Sip roofs have extreme advantages over traditional framed roofs. Venting at the ridge and eave allows air to move freely between the two layers of sheathing. Integrated sheathing and roof deck for a one stop roof framing product. The roof is currently built as follows.

These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck. Extreme insulation up to r 51. 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. If you would like to receive a price quote on a sip project please request a sip quote.

When constructing unvented roofs with asphalt shingles in hot humid climates a vapor barrier must be installed between the asphalt shingles and the roof deck. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction. Four options for building an unvented roof assembly. 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.

Factory engineered and precut per floor plans all but eliminating measuring or cutting material for roof structures. 1 1 2 t g decking. 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. Beams on 5 centers.

With tribuilt granulated self adhering underlayment on top of the plywood. If you don t want to use sips or nailbase there are four basic approaches.