Unvented Sip Roof

Create a cold roof by applying a layer of sheathing over 1 3 furring 16 in.

Unvented sip roof.

3 8 plywood diaphragm seams taped. With tribuilt granulated self adhering underlayment on top of the plywood. 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. If you don t want to use sips or nailbase there are four basic approaches.

Asphalt shingles store water from dew condensation due to night sky cooling and rain. 1 1 2 t g decking. 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.

Therefore an unvented sip roof is permitted under irc r806 5 unvented attic and unvented enclosed rafter assemblies. The 2012 irc permits unvented roof assemblies including unvented sips. 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. 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.

The roof is currently built as follows. Integrated sheathing and roof deck for a one stop roof framing product. Need to make a final decision on which underlayment to use under a metal roof on an unvented roof system. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction.

With an unvented sip roof the argument would be that the exterior osb facing constitutes the structural sheathing referred to in the code. Venting at the ridge and eave allows air to move freely between the two layers of sheathing. This style of roof helps to prevent moisture buildup. Factory engineered and precut per floor plans all but eliminating measuring or cutting material for roof structures.

Beams on 5 centers. This receptor is an air space that can be accomplished in a variety of ways. In order for an un vented roof assembly to function properly the following conditions must be in place. Four options for building an unvented roof assembly.

Sip roofs have extreme advantages over traditional framed roofs. If you would like to receive a price quote on a sip project please request a sip quote.