Closed Cell Spray Foam Insulation Alberta

Why density changes everything

2 lb closed cell and half pound open cell are the two density grades you will be quoted in Alberta, and the difference decides the assembly. Open-cell foam is mostly trapped air in a soft matrix - great for sound and interior walls, but it drinks water and can't stop vapour. Closed-cell's tight, rigid cell structure flips all of that: it resists moisture, adds structural rigidity to a wall or panel, and holds its rated R-value long-term (LTTR). That combination is exactly what Alberta's freeze-thaw, high-humidity-indoors, bone-dry-outdoors winter demands.

Where closed cell spray foam insulation belongs

• Basements & below-grade walls - 2" gives roughly R-12 to R-14 and shuts down the condensation that ruins framed-out basements; 3-4" reaches R-18 to R-28 in tight cavities.
• Crawlspaces - seals the cold, damp floor of the house.
• Rim joists - the single leakiest band in most homes.
• Metal & steel buildings - stops the sweating that drips off an uninsulated metal roof.
• Exterior walls, roofs, tanks, containers - anywhere moisture or structure matters.

Spec and standards

Closed-cell medium-density SPF is manufactured to CAN/ULC-S705.1 and installed to S705.2 by a CUFCA-certified applicator whose photo ID is renewed yearly. The manufacturer's product data sheet governs the exact spec on your job; a good installer specs thickness to your target R-value, not to a rule of thumb. In occupied space it's finished with a code-required thermal barrier.

Closed Cell Spray Foam Insulation Alberta: Common Questions

What R-value does closed cell spray foam give per inch? Roughly R-6 to R-7 per inch. That is the highest of any insulation commonly used in Alberta houses and buildings, and it is why closed-cell wins where cavity depth is limited - a 2x6 wall, a shallow crawlspace, the underside of a roof deck.

How thick does closed cell foam have to be before it is a vapour barrier? About two inches. Below that it still insulates and air-seals, but it is not yet doing vapour control, so the assembly needs a vapour retarder designed in. That threshold is the single most misunderstood number in spray foam, and it is why "we sprayed an inch" and "we sprayed two" are different assemblies rather than different amounts of the same one.

How much closed cell foam does an Alberta basement need? Two inches gives roughly R-12 to R-14 and shuts down the condensation that ruins framed-out basements. Three to four inches reaches about R-18 to R-28 where the cavity allows it. Which one your build calls for depends on the wall assembly and your target R-value, not on a rule of thumb.

Should I use closed cell or open cell? Closed-cell wherever the assembly meets weather, ground or steel - basements, crawlspaces, rim joists, metal buildings, exterior walls and roofs. Open-cell suits interior walls and sound separation, where its softness is an advantage and moisture is not in play. Most houses end up with both, in different places.

Does closed cell spray foam have to be covered up? In occupied space, yes - it is finished with a code-required thermal barrier. That is part of the job, not an extra, and any quote you are given should already account for it.

How is closed cell spray foam priced? By the board foot: one square foot at one inch thick. So the drivers are area, the thickness your target R-value takes, which foam the assembly needs, and access. Estimate your own board feet with the foam calculator before you speak to anyone. No number is worth anything until someone has seen the building.

Not sure closed-cell is what your project needs? Compare it with open-cell, or get a quote and we will spec it.