Spray Foam Insulation Code Requirements
Spray Foam As a Product
Spray foam insulation is a versatile building product that is used in commercial and residential construction as well as renovation projects and new building construction. You might be familiar with spray foam product for wall insulation, but spray foam can be used in many parts of a home and buildings.
Spray foam insulation products are categorized as either “air-impermeable” and “air-permeable” looking at the installed thickness. Closed-cell types may be rated as “air-impermeable” with less than an inch thickness, whereas the less-expensive open-cell types may require 4 inches or more, or may not be “air-impermeable” at any thickness.
- Air-impermeable insulation applied on to the underside of the roof sheathing.
- Air-permeable insulation between the roof joists, with a category III vapor retarder coating or covering applied on to the underside of the insulation. (A Class III vapor retarder could be as simple as a coat of latex , but any coating applied must be specifically recognized by the spray foam manufacturer’s written instructions.)
- Air-permeable insulation applied to the underside of the roof deck, with minimum R-10 rigid insulation above the roof deck.
- Air-permeable insulation applied to the underside of minimum R-10 air-impermeable insulation (spray foam or rigid board), which is applied directly to the underside of the roof deck.
Spray foam insulation as a useful energy conservation.
Spray foam insulation can also serve as a useful energy conservation tool. Even though spray foam is more expensive than conventional fiberglass batt, some foam types provide almost double the insulation value of fiberglass. Spray foam will fill perfectly all odd-shaped spaces, and certain varieties will also function as a vapor retarder and air barrier.
However, the spray foam products available on the market have different characteristics so it's important to work out the right spray foam for your project.
Proper Spray Foam Application
Proper application of insulation materials is critical to the success of any new Green House project. Here are some guidelines in addition to the code requirements:
• Spray Foam Insulation product shall be installed to manufacturer’s specifications, with no gaps, voids or compressions, including around electrical boxes, around pipes and in corners.
• Rating the installation of insulation—The building might not receive the very best quality rating if proper insulation installation isn't verified by a pre-drywall inspection or other approved methodology.
• Air barriers and eave baffles to stop wind washing—No matter how well insulation is installed, cold air washing through it will not only severely compromise its effectiveness, but also increase condensation potential by cooling the vapor retarder. Eave baffles made from cardboard or foam board are essential; if the baffle extends above the highest of the insulation, no vent chute or “propavent” is required. Also vulnerable are exposed insulated walls, like attic knee walls . Cover the exposed fiberglass on the attic side with a vapor permeable air barrier like housewrap, polystyrene foam, drywall, or similar material. Floor insulation over piers, cantilevers and therefore the like should even be sealed to prevent outside air from circulating into the insulation. Flat or sloped attic insulation doesn’t need to be covered, but baffles should be provided near eaves.
• Avoid strapped ceilings—1x3 furring strips running perpendicular to the joists provide a cavity for free air circulation, which often compromises the insulation performance, especially near eaves and in cathedral ceilings. Once nailed in place, they also make it very difficult to install insulation properly. This is another area where your money can be saved while thermal performance will be improved.
• Higher R-values in sloped ceilings are often achieved with smaller framing by adding sister joists with plywood gussets.
The Ontario insulation building code requirements for insulation has specific guidelines for installation and materials. All insulation materials in Ontario will have to meet specific requirements set out by the national government. To be available on the market, manufacturers take care of this step before their products are even available - which is why it’s important to make sure that you’re buying new insulation instead of dead stock material found in someone’s garage.
Some of the finer points of the Ontario building code requirements for insulation govern the exact installation of the product to make sure that all the different component parts will not only work but last over time. Here are some example rules:
- By the Ontario building code, insulation must be in contact with an air barrier. This prevents it from being compromised by convective airflow through the materials. An air barrier can be many things, such as exterior sheathing or a vapour barrier.
- Insulation susceptible to water damage must be kept a minimum of 2” above a crawl space floor
- Where insulation is exposed to the weather, it must be kept protected by 6mm thick preservative plywood or 12mm cement parging.
Installation of Loose-Fill Insulation
Another type of insulation we often see is loose-fill. The Ontario Building Code states that:
- Loose-fill insulation must not settle after installation
- Be covered by a membrane that can be seen through
- Must not bulge or interfere with interior finishes
EcoStar’s insulation team strives to provide the best quality products and the highest standard of expertise. Our professionalism and experience goal is that you never have to worry about anything less than thorough and complete workmanship. Our professionals will guide you from the consultation to the execution stage. Contact us for your free estimate.