John Robison
What do I need to do to install a new metal roof over an existing metal roof? The building is not insulated but there is electricity. I have been told yes I can but I have to put down a moisture barrier first. I have been told no because it will rust out too quick I have been told yes but you have to raise the roof a little to allow airflow I have been told no because it will be too heavy .. Here is a picture of my building the existing roof is in good shape but has some rust.
Eric Novotny
An informed customer is the Best Customer!
Depends on the application. If you are not conditioning the space, the ventilation requirements are not the same. You will probably need to install the new roof on purlins and some sort of slip layer/WRB across the top of the old roof would be advisable. Check with the manufacturer of the new system that you are considering.

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