Green Building Advisor Venting Flat Roofs

So i ll start by saying something that might sound controversial but really isn t.

Green building advisor venting flat roofs.

The room does not have any venting nor is it possible to vent. If you re actually going to vent the roof let s be serious about venting the roof. Part h of the building regulations regarding drainage state that water should drain to one or two edges. Wash the underside of the roof deck with air.

2 if you re going to vent the roof then vent the roof. He says ruling out a layer of exterior rigid foam. When installing or repairing a flat roof you must adhere to building regulations. 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. 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. 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. Originally published may 1976.

There must be a slope of 1 80. That means the entire perimeter of the roof needs to have air inlets meaning continuous soffit ventilation. Venting of flat roofs. Musings of an energy nerd.