Cold Roof Ventilation Gap

A cold roof is where all of the insulation is placed either between and under or completely under the joists or deck.

Cold roof ventilation gap. See the benefits of attic ventilation a new roof is more than just shingles. You only need ventilation in a cold roof. In this way the roof itself is kept cold. Introduction warm cold roofs this guidance offers guidance on the difference benefits between warm and cold roofs.

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 a cold climate the primary purpose of ventilation is to maintain a cold roof temperature to avoid ice dams created by melting snow and to vent any moisture that moves from the conditioned. Where this is the case all gaps and holes around service that pass into the cold roof via the ceiling should be sealed to restrict the amount of water vapour that. Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.

The intent of roof venting varies depending on climate but it is the same if you re venting the entire attic or if you re venting only the roof deck. Effective attic ventilation systems reduce damaging heat and moisture in your attic promote energy efficiency by helping to reduce the load on your air conditioner in the summer and also reduce the risk of ice dam formation on your roof. In order to keep the integrity of the roof it is recommended to install vmzinc breather membrane on the cold side of the insulation and a vapour control layer adapted to the internal humidity load of the building on the warm side of the insulation. Ventilation is not needed in a warm roof.

Building regulations state that a ventilation gap of at least 50mm must be in place between the insulation and the underside of the flat roof deck. Continuous ventilation openings are made at the top and bottom. Large cold pitched roof voids can be used to locate services such as water storage tanks associated pipes ventilation ducts electrical cables and recessed light fittings. For both a warm and cold flat roof a vapour control layer must be installed.

Roof voids must be ventilated in order to stop warm air condensing on cold surfaces. Condensation encourages rot and mould growth. Intake vents located at the lowest part of the roof under the eaves allow cool. Ventilation is required for these roofs.