Unvented Roof Ontario

1 nails nails used for roofing shall be corrosion resistant roofing or shingle nails conforming to csa b111 wire nails spikes and staples.

Unvented roof ontario.

1 1 2 t g decking. The most common way to eliminate venting from a roof assembly is to use a spray foam spf insulation. According to the building code an unvented roof assembly needs r 20 of rigid foam above the roof sheathing for climate zone 5 or r 25 of rigid foam above the roof sheathing for for climate zone 6. We have 7 on the entire underside of the roof.

Once you have r 20 or r 25 of rigid foam on top of your sheathing you can safely insulate below your sheathing with almost any kind of. When we renovated our home we changed our addict being unvented. Next i ll be screwing down 5 1 2 raycore sips panels over heated space and framing. These roofs are code conforming except they do not display the venting requirements expressed in the building code.

Unvented roofs are more common in today s modern home designs. Hopefully a roofing contractor never makes a mistake with nails. 3 8 plywood diaphragm seams taped. An understanding of heat air and moisture as well as the causes of condensation is critical in detailing unvented roof assemblies.

We didn t open up the 1st and 2nd floor walls but did going to the basement and spray the rim joists and any other open available areas. Unvented roofs are increasingly common due to design priorities. 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. Nails shall have sufficient length to penetrate through or 12 mm into roof sheathing.

Hi everyone need to make a final decision on which underlayment to use under a metal roof on an unvented roof system. The roof is currently built as follows. Potential pitfalls to avoid include. Beams on 5 centers.

A combination of vented and unvented assemblies was studied including vented fibreglass. The primary concern with the use of unvented cathedralized attics is the potential for moisture build up at the underside of the roof sheathing during cold weather. We had closed cell foam sprayed on the underside of the roof. Unvented roof assemblies such as conditioned attics and unvented cathedral ceilings are becoming common in north american construction.

These assemblies are created by eliminating ventilation openings and moving the thermal moisture and air control boundaries to the plane of the roof deck. For more than one year the university of waterloo s building enclosure group beg studied both open and closed cell foams in field in a test hut environment in southwestern ontario. Preventing moisture is essential for having a properly functioning un vented roof.