Selecting the right underlayments for a lifetime metal roof should be a primary concern for anyone thinking about specifying or choosing to install a metal roof on their home.
Leaving shingles under metal roof.
1 remove the shingles before installing the metal roof the first way to install a metal roof over shingles is by completely removing the old shingles before installing the new metal roof.
Overgrown trees debris and even snow can scuff up the surface.
In addition metal roof pipe flashing will be needed for round pipes and penetrations.
However scratches down to the metal can be problematic.
Every situation will be different but generally speaking installing one of the more heavily textured metal roofs such as a corrugated vertical seam or or a horizontal metal shingle over your existing shingles should not be a problem.
Metal roof over shingles condensation metal roofs must be laid flat on a vapor barrier because steel will condensate if there s any air space underneath it.
However before you decide on reroofing with a metal roof you have to keep in mind that there are specific conditions that make reroofing with a metal roof safe.
I would argue that putting sheet metal roofing over existing shingles if going to always look just at leat a little bit junky because the surface they are starting with is uneven and somewhat compressible.
Well that s why the metal roof is such like an eco friendly product because you don t have to get rid of all of that stuff to the landfills.
A benefit to doing it this way is that you can see if there is any rotten plywood that needs to be replaced before installing the new roof.
Tin roofing also known as metal roofing is considered more durable than composition or wood shingles.
Installing wood stripping under a tin roof.
At some point during its lifecycle you can expect the metal panels to get scuffed or scratched.
You will want to install layer of underlayment between the old and new roofs.
The roofing is manufactured in panels that.
In some instances this can lead to punctures and tears that result in leaks.
Put the steel down directly on a vapor barrier.
Several of the contractor responses say why not leave perfectly good shingles under the metal roofing rather than remove them.
Metal roof flashing will still be needed around chimneys skylights and where roofs hit a wall sidewall endwall.
Some roofing contractors recommend reroofing with standing seam metal because the total roof weight is but a fraction of a standard asphalt shingle roof which helps preserve the roofing integrity.
Even if you leave your shingles you will need to remove ridge venting material and caps.