Green Building Advisor Venting Flat Roofs

He says ruling out a layer of exterior rigid foam.

Green building advisor venting flat roofs.

An air permeable insulation like mineral wool cannot be installed between rafters if the assembly is unvented. Part h of the building regulations regarding drainage state that water should drain to one or two edges. So much information has been devoted to the subject of roof venting that it s easy to become confused and to lose focus. A qualified roofing contractor will be able to advise on this but here are some of the main guidelines.

2 if you re going to vent the roof then vent the roof. Originally published may 1976. The room does not have any venting nor is it possible to vent. Musings of an energy nerd.

The flat roof overhead is framed in full depth 2x6s finished with what jordan believes is roll roofing a type of asphalt roofing. 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. If you re actually going to vent the roof let s be serious about venting the roof.

So i ll start by saying something that might sound controversial but really isn t. When installing or repairing a flat roof you must adhere to building regulations. 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. That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation.