Green Building Advisor Venting Flat Roofs

Originally published may 1976.

Green building advisor venting flat roofs. 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. He says ruling out a layer of exterior rigid foam. The room does not have any venting nor is it possible to vent. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines.

That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation. Part h of the building regulations regarding drainage state that water should drain to one or two edges. When installing or repairing a flat roof you must adhere to building regulations. Venting of flat roofs.

Musings of an energy nerd. If you re actually going to vent the roof let s be serious about venting the roof. 2 if you re going to vent the roof then vent the roof. 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.

Wash the underside of the roof deck with air. So i ll start by saying something that might sound controversial but really isn t. An air permeable insulation like mineral wool cannot be installed between rafters if the assembly is unvented. 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.