the Shop under a New Roof
Can old rolled asphalt roofing be trapped under a new roof without harm?
My backyard shop is a gable roof building that was once a small garage. When it was converted to a shop, a carport was built on to one side.
Probably 15 years ago, both the shop and carport were covered with roll roofing. Since it starts at the shop eves, the angle of the carport roof is very shallow. Carrying quite a bit of snow the last 2 Winters, the carport roof begun leaking. The roof deck and even the rafters are in bad shape now.
I guess the carport roof is over 40 years old Â it should be entirely removed. If a new carport roof starts at the peak of the shop, the angle would be much steeper and better for shedding water.
Starting at the peak of the shop would trap that slope of the shop roof beneath this new roof. I will use metal roofing over the entire structure Â both shop and carport. Is there a problem with leaving the existing asphalt roofing on the shop and simply covering it with the metal roofing?
I donÂt know if it makes any difference but keep in mind that the new roof would sit directly on one slope of the shop and be elevated above the other slope. To keep the birds out of there Â IÂd enclose that area with OSB board.