If you want to install steel over asphalt your best choice for installing metal roofing is to use a steel shingle system like the one shown instead of the more common and more expensive standing seam steel.
How to install metal roofing on shingles.
If you don t know how to cut metal roofing panels you can warp them or damage the protective coating that prevents rust.
Install metal panels or shingles align the first metal roofing panel so that it overlaps the edging by 1 2 to 3 4 of an inch and is square to the roof line.
Codes vary so call your local building department to know how to install metal roofing over shingles properly code wise.
Metal roof over shingles condensation.
You should start your metal shingles installation with half a shingle or in accordance with your metal shingles installation manual which should be system specific starting from the left of the starter flashing or gable.
Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it.
Anatomy of a steel roof.
Metal roofing is much more difficult to install than asphalt shingles.
Put the steel down directly on a vapor barrier.
What s involved in how to install metal roofing.
In a standing seam roof long single panels run vertically all the way from the eave to the ridge.
Install the roofing screws vertically along each rib in the panel.
You will also need to invest in some specialty tools to help you get the job done.
Experts recommend that you work diagonally and raising each row of shingles gradually.