Green Building Advisor Venting Flat Roofs

If you are planning to install mineral wool insulation on the interior side of the roof sheathing you will need to include a ventilation channel between the top of the insulation and the underside of the roof sheathing.

Green building advisor venting flat roofs.

If you re actually going to vent the roof let s be serious about venting the roof. Venting in building construction as a technique of cooling by air flow and of controlling or removing moisture has been in use for many years. So i ll start by saying something that might sound controversial but really isn t. The flat roof overhead is framed in full depth 2x6s finished with what jordan believes is roll roofing a type of asphalt roofing.

A qualified roofing contractor will be able to advise on this but here are some of the main guidelines. Part h of the building regulations regarding drainage state that water should drain to one or two edges. A vented attic where insulation is placed on an air sealed attic floor is one of the most underappreciated building assemblies that we have in the history of building science. When installing or repairing a flat roof you must adhere to building regulations.

Originally published may 1976. That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation. There must be a slope of 1 80. So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus.

Wash the underside of the roof deck with air. The room does not have any venting nor is it possible to vent. Venting of flat roofs. 2 if you re going to vent the roof then vent the roof.