Unvented Sip Roof

Factory engineered and precut per floor plans all but eliminating measuring or cutting material for roof structures.

Unvented sip roof.

This document provides a brief description of different types of unvented roof assemblies and the benefits of unvented roof construction. 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. 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. Need to make a final decision on which underlayment to use under a metal roof on an unvented roof system.

1 1 2 t g decking. This receptor is an air space that can be accomplished in a variety of ways. 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.

This style of roof helps to prevent moisture buildup. 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. These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck. Therefore an unvented sip roof is permitted under irc r806 5 unvented attic and unvented enclosed rafter assemblies.

Beams on 5 centers. Venting at the ridge and eave allows air to move freely between the two layers of sheathing. The 2012 irc permits unvented roof assemblies including unvented sips. 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.

With an unvented sip roof the argument would be that the exterior osb facing constitutes the structural sheathing referred to in the code. Four options for building an unvented roof assembly. Sip roofs have extreme advantages over traditional framed roofs. The roof is currently built as follows.

If you don t want to use sips or nailbase there are four basic approaches. If you would like to receive a price quote on a sip project please request a sip quote. In order for an un vented roof assembly to function properly the following conditions must be in place. Create a cold roof by applying a layer of sheathing over 1 3 furring 16 in.

Integrated sheathing and roof deck for a one stop roof framing product. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction.