Flat roof insulation challenge met
August 9, 2019
Flat roofs on both detached houses and new condominium apartment buildings are becoming popular in larger Canadian cities as the cost-per-square-foot for living space rises. In Vancouver or Toronto, this can now equate to $750 per square foot or more and surpasses $500 in central Montreal.
A big advantage for home builders and renovators is that flat roofs are much easier to work on than sloped roofs, which can trim labour costs.
A deterrent to flat roofs is a fear of higher maintenance costs due to ponding water and leaks through conventional insulation, such as insulation panels. But Doug Kramer, president of Icynene-Lapolla Canada, said using spray-foam insulation can be a solution.
“Spray foam creates an uninterrupted, impermeable surface for the roof without any seams, penetrations or voids that could let water in” Kramer explained, adding that spray foam can be applied in multiple layers and at varying thicknesses to create better drainage and less chance of water pooling on a flat roof surface.
Kramer estimated that a spray foam roof has an R-value of 6.5 per inch and can produce energy savings of 30 percent or more compared to alternative roofing systems, “so a spray-foam insulated roof can pay for itself in five years.”
Contractors must be aware that Canada will be phasing out the import of hydrochlorofluorocarbons (HFCs) – including closed cell foam blowing agents used in spray foam insulation – completely by 2020. This means that only spray foams that use hydrofluoroolefins (HFOs) or other additives that have low global warming potential can be used.
Icynene-Lapolla and other leading spray foam manufacturers have developed or are introducing such low-emission insulation.