Make sure roof is square.
How to install metal roofing over shingles youtube.
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.
In this video i m installing some metal roofing over an existing ash fault shingled roof.
Otherwise you will need to remove the shingles.
This is part 1 of a 6 part video series explaining how i installed a metal roof on my house.
As long as the plywood under the shingle roof is in good condition this way can provide many benefits.
However you should only install a metal roof over shingles if you have less than four layers of shingles on the roof.
In this video i cover measuring the roof figuring the metal th.