Gap Between Roof Sheathing And Batt Insulation

Still you need to make sure that the gap is not more than 1 8 inch.

Gap between roof sheathing and batt insulation.

Batts secured to the deck with insulation hangers between top chords or more commonly tension cables secured at the ridge and eaves with eye hooks to prevent fall out. Shingles roofing felt stackups are on the boundary between class i class ii vapor retardency when dry at about 0 1 perms and when the roof is wet there is. Use baffles between each rafter space to prevent it from being blocked see figure 5 11. Unless you have at least a 1 gap between the roof deck and roxul with both ridge soffit venting putting putting foil facers on the interior side is going to create a moisture trap.

Batts should cover the top plate of the exterior wall but not block the venting. Here is a fact. You can then apply batt insulation around the foam without worrying too much about the air space. Leave gaps between panels you need a gap on the roof so your room could breathe.

When you found gaps or channels between the insulation pieces it is better to leave it that way so the air could get into the house. Apply a 2 inch layer of spray foam insulation r 10 to r 12 directly to the interior surface of the roof sheathing. This will keep the surface warm and help minimize condensation. Hole in the roof sheathing near the center of your roof so that you can install a doghouse above the roof to act as a vent outlet.

If you use air permeable insulation and it is not in direct contact with the air barrier in this case the plywood roof deck you will experience convective.