GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted
Detail Library

Vented Attic & Siding for Cold Climate (Scissor Truss). Wood Shingle Roofing; Brick Veneer Siding Over Rigid Foam (Furring Strips)

Corners and connections are where insulation and air barriers can have trouble. Compressed or insufficient insulation can cause cold spots, which lead to condensation, mold, and rot. Air leaks at this connection can cut the effectiveness of the insulation substantially. In cold climates, this is where ice dams begin.

To keep the air barrier continuous, span the wall sheathing over the framing connection and use adhesive or sealants at framing connections as shown.

Roofs and walls need to dry

Moisture from both outside and inside a house can thwart your best efforts at keeping the building dry. Moisture in roof and wall assemblies is inevitable, so it's a good idea to design them so that they can dry. Roofs and walls that can dry to either the outside or inside are good, but those that can dry both directions are even better.

Vented attics can keep a roof dry

Outdoor air that enters soffit vents and is exhausted through a ridge vent can help roof sheathing to dry if it ever gets damp.

Ventilation may help keep roofs cool

Although roof ventilation is often perceived as an effective way to cool off attics during the summer, studies show that it's hard to lower attic temperatures very much by ventilation alone. However, most building scientists agree that attic ventilation can lower the chance of ice damming in snowy climates. For more information on preventing ice dams, see Prevent Ice Dams With Air Sealing and Insulation.

Roofs leaks are harder to spot in cathedral ceilings

Sometimes a water stain inside the house isn't anywhere near where leaked in. It's easier to find roof leaks in a ventilated, unconditioned attic than in a house with an insulated cathedral ceiling.

The usual way to vent a roof is with continuous soffit vents acting as…

GBA Prime

This article is only available to GBA Prime Members

Sign up for a free trial and get instant access to this article as well as GBA’s complete library of premium articles and construction details.

Start Free Trial

Related

Community

Recent Questions and Replies

  • |
  • |
  • |
  • |