Metal Roof On Top Of Asphalt Shingles

The purlins are screwed or nailed down to the roof deck depending on how the metal roofing manufacture has testing for their roofing panels and then the metal is installed to the purlins.

Metal roof on top of asphalt shingles.

Metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it. It doesn t matter if the air space is a half inch or six inches because the condensation factor will remain the same. Wood framework base for the metal but the way that we get around it with the steel roofing is to construct a wood framework of one by four s and then lay the metal on top of that framework. So if your roof has two layers it may require a complete tear off even though steel is lighter than asphalt.

Both metal and shingle roofs are great options for your next roofing project. 3 install 1x4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1x4 purlins over the shingle roof. As long as the plywood under the shingle roof is in good condition this way can provide many benefits. If you are trying to decide between the two materials it s important to carefully look at the metal over shingle roof problems.

Metal roof over shingles condensation. This method has its benefits as well. It is very much like constructing a non loadbearing interior wall framework and sticking that framework on top of your roof. The second way to install a metal roof over a shingle roof is with the use of purlins or battens.

After all you ll be making a significant and long term investment. Can you avoid tearing off your old asphalt shingle roof by putting a steel roof over it. Most codes now allow no more than two layers of roofing before requiring a complete tear off.