Un-vented Roofs, commonly referred to as 'Hot Roofs" have become more and more common in new construction in the last 10 years, usually referring to a roof with no vent space between the insulation and the roof sheathing.
Traditionally, roof areas are vented with a few inches of space between insulation and the roof surface, allowing for heat to dissipate, instead of exiting directly through the roof sheathing.
Our company, Thermo Seal Insulation Systems works in areas of Central Ontario, Canada where the annual snowfall is very high, and summer temperatures are high as well. We have insulated, and warranted hundreds of homes, businesses and cottages in snow-belt areas, and understand insulation and venting these kinds of buildings better than companies working in areas with mild winter weather.
We recommend that every area of your roof is properly ventilated, including cathedral ceilings and areas insulated with spray foam. Ice build-up from melting snow is a real problem with hot-roofs, and only proper venting can make that avoidable.
In custom construction, and retrofit insulating there are some instances where it is extremely difficult to insulate without hot-roofing, and sometimes an architect or engineer insists on a hot roof application. It is never our first choice, and we will always recommend venting if possible. If the building has a simple steel roof(with no valleys), the hot and cold cycle of the hot roof may not cause any damage because the ice/snow will slide off the roof, and not stick. This is not always the case, especially with a very heavy snowfall overnight.
Be very cautious if you have a contractor recommend hot-roofing, or disregarding the need for venting in your attic, especially if you live in a cold climate, with snow that stays on the roof for weeks on end.
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| Vented(Cold) and Non-Vented("Hot Roof") |
Traditionally, roof areas are vented with a few inches of space between insulation and the roof surface, allowing for heat to dissipate, instead of exiting directly through the roof sheathing.
Our company, Thermo Seal Insulation Systems works in areas of Central Ontario, Canada where the annual snowfall is very high, and summer temperatures are high as well. We have insulated, and warranted hundreds of homes, businesses and cottages in snow-belt areas, and understand insulation and venting these kinds of buildings better than companies working in areas with mild winter weather.
We recommend that every area of your roof is properly ventilated, including cathedral ceilings and areas insulated with spray foam. Ice build-up from melting snow is a real problem with hot-roofs, and only proper venting can make that avoidable.
In custom construction, and retrofit insulating there are some instances where it is extremely difficult to insulate without hot-roofing, and sometimes an architect or engineer insists on a hot roof application. It is never our first choice, and we will always recommend venting if possible. If the building has a simple steel roof(with no valleys), the hot and cold cycle of the hot roof may not cause any damage because the ice/snow will slide off the roof, and not stick. This is not always the case, especially with a very heavy snowfall overnight.
Be very cautious if you have a contractor recommend hot-roofing, or disregarding the need for venting in your attic, especially if you live in a cold climate, with snow that stays on the roof for weeks on end.
