Ceiling Spray Foam Insulation Alberta

Two different ceilings, two different jobs

A ceiling with a vented attic above it. Here the ceiling is the air barrier and the attic holds the insulation. Foam's job is sealing - at pot lights, plumbing stacks, bath fans, top plates and the attic hatch - after which blown-in provides depth cheaply. See attic insulation.

A ceiling with no attic above it. Cathedral ceilings, vaulted rooms, flat roofs and the ceiling under a bonus room. There is no space to blow insulation into and the assembly depth is fixed by the structure. This is where foam becomes the insulation rather than just the air seal.

Why cathedral and vaulted ceilings are hard

A cathedral ceiling gives you a rafter depth and nothing else. Fitting enough batt into it to reach a real R-value is usually impossible, and the ventilation channel that the assembly needs eats depth you do not have.

Closed-cell solves it on both counts: the highest R per inch of any sprayed product, and no ventilation channel required in an unvented assembly. Six inches of closed-cell in a 2x8 rafter bay delivers what no batt assembly can in that space.

Unvented roof assemblies must be designed for the climate zone. This is not a place to improvise.

Flat and low-slope roofs

Alberta has a great many low-slope residential and light-commercial roofs, and they are chronically under-insulated because there is nowhere to put insulation.

Sprayed to the underside of the deck, closed-cell fills the joist space and seals it in one pass, which is often the only practical retrofit available without rebuilding the roof.

Ice dams start at the ceiling

Ice damming is not a roof problem. It is warm air escaping through the ceiling plane, melting snow on the roof, and the meltwater refreezing at the cold eave.

The fix is at the ceiling, not the gutter. Sealing the ceiling plane removes the heat that causes the melt. Heat cables treat the symptom and run up your power bill doing it.

Ceiling Spray Foam Insulation Alberta: Common Questions

Can foam go over my existing ceiling insulation? In an attic, foam is used to seal the penetrations and blown-in goes over. Spraying over old, settled insulation does not seal anything because the leaks are underneath it.

How thick for a cathedral ceiling in Alberta? Commonly five to eight inches of closed-cell, driven by the target R and by the rafter depth available. The assembly needs to be designed as unvented, which our installers will confirm.

Will this stop my ice dams? If the dams come from heat escaping through the ceiling - which is the usual cause - yes. If they come from a poorly detailed valley or an inadequate eave membrane, that is roofing work.

Does foam at the ceiling help with noise between floors? Open-cell in a floor assembly damps airborne sound well. It does less for footstep impact noise, which needs decoupling. See soundproofing.

Get the assembly quoted

Get a free quote with the ceiling type, the structure depth and whether there is an attic above. See attics, bonus rooms and spray foam roofing.