What is a cold roof?

Q:
What is a cold roof?

A:

A cold roof is an insulated roof system that does not ventilate.  This system is widely used for flat roofs. The insulation is commonly laid on top of the roof deck and the roofing membrane is adhered over top.

Sometimes when ventilation is a problem in sloping roofs, the insulator will foam insulate the roof cavity from underneath to achieve an insulated cold roof system.  It is important that this type of roof system stops any interior vapour from penetrating the insulation.

You can have parts of a roof system be a cold roof and other parts that are conventional. In most custom homes there are area’s in the roof because of design or the way that it was constructed that there isn’t a way for the roof to ventilate, these area’s must be spray foamed to achieve a proper cold roof. This will then insure that there isn’t a ventilation problem in that area down the road.

Ventilation problems can lead to condensation problems. You can have a condensation problem from a non venting roof that is so severe that you will swear the roof is leaking.

When insulating a home special attention should be paid to any area that is deemed unventible or even has the ability to have poor venting. Your contractor and your insulator need to work together to achieve a proper balance between proper venting and a proper insulation seal.

When insulating a home there has to be a wide picture view taken of the whole home and how the building envelope will be insulated. This is the best way to achieve a near perfect insulating job where there is a high R-value with little to no ventilation problems down the road.

Rob Abbott
Operations Manager
Village Builders Inc.