Green Building Advisor Venting Flat Roofs

The room does not have any venting nor is it possible to vent.

Green building advisor venting flat roofs.

Musings of an energy nerd. 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. There must be a slope of 1 80. If you re actually going to vent the roof let s be serious about venting the roof.

Wash the underside of the roof deck with air. An air permeable insulation like mineral wool cannot be installed between rafters if the assembly is unvented. 2 if you re going to vent the roof then vent the roof. When installing or repairing a flat roof you must adhere to building regulations.

So i ll start by saying something that might sound controversial but really isn t. Originally published may 1976. Venting of flat roofs. 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.

He says ruling out a layer of exterior rigid foam. That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation. 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.