Roofing/lean-to roof


Bryan wrote at 2008-03-20 13:44:12
You are quite correct in calling it a lean to roof. Often called a mono-pitch. With regard to venting the roof you should ideally leave  a 2 inch gap between the roof felt and the insulation. You can purchase items call abutment vents which will do what you want, or you will need tile vents. (unfortunately between each rafter). The other alternative method is to use a breathable roof felt. In which case you just leave the same gap but you don't need to provide soffit or high level ventilation.

Also If you have a cavity wall you should use a cavity tray and not just a flashing to stop water penetration through the cavity.

Hope this helps and good luck

Bryan  from England ( better get back to my own building plans now!)

Andy wrote at 2013-10-25 14:31:39
For venting the roof against the wall try this -


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Brad Zacharia


All aspects of residential Roofing. This includes shingles and flat (low slope) roofs. I have knowledge in the installation as well as the design of roofs from an engineering standpoint.


I have been doing roofing for 40 years. This was my father's business and I took it over in 1980.

I have written responses to artcles that I felt needed a response to and those responses have been published in roofing trade magazines.

BSEE Drexel University

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