Cold Deck Roof Insulation

Zones 5 6 7 and 8 in that the manufacturers of these materials assume that roof deck may require ventilation to assist drying.

Cold deck roof insulation.

Cold roof sheathing is one of many components in keeping ice dams at bay. It can also be used as a roofing cover board and in building envelope applications. Rigid insulation used to control condensing surface temperatures rigid insulation installed above roof deck. Where insulation depth is restricted by the flat roof construction it may be necessary to install the roof insulation between and below the joists to create a cold deck structure.

This construction relies on a vapour control layer working effectively and in tandem with a continuous ventilated airspace to disperse the water vapour to atmosphere before it reaches the cold deck and condenses. If spray foam is used a vent space may still be needed directly under the roof deck. A cold roof has the insulation placed below the structural deck which thus remains cold. It is a thermoset closed cell foam that is an optimal insulation solution for low slope roofs.

Care should be taken with these assemblies particularly in cold climate zone locations i e. Ventilation is required for these roofs. Warm roof insulation ensures the entire roof structure is insulated meaning a warm deck roof is more energy efficient than a cold roof. Hence the term cold decks construction materials wood based products absorb moisture.

The breakdown warm roof vs cold roof. The roof deck is cold wood decks without insulation above them will readily equilibrate to the exterior temperature. Polyisocyanurate thermal insulation also referred to as polyiso pir or iso is a popular low slope commercial building roof insulation. Cold deck roof a cold deck roof is where the insulation is placed between the joists rafters or in between the ceiling joists in the case of a pitch roof.

In cold and very cold climates selecting a roof deck condensing surface temperature criteria of 45 f is very conservative. During cooler night times and in winter periods the deck temperature can then be below the dew point of the interior air. This method of insulation can also be used to upgrade the thermal performance of an existing roof without affecting the waterproofing system. The second and nearly as important goal is to keep the roof deck as cold as possible during upstate new york winter months.

Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs. Ratio of r value between rigid insulation and batt insulation is climate dependent.