As long as the plywood under the shingle roof is in good condition this way can provide many benefits.
Installing metal roof over shingles youtube.
Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps.
However you should only install a metal roof over shingles if you have less than four layers of shingles on the roof.
Cool outside air travels under the shingles to the vented ridge pulling out moisture and heat.
A metal roof is an alternative to a shingle covered roof but a metal roof can actually be installed over shingles.
A steel roof is a lifetime investment lasting 50 years or more if it s a good one.
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.
Otherwise you will need to remove the shingles.
Can you put metal over shingles.
Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails.
In a standing seam roof long single panels run vertically all the way from the eave to the ridge.
This is by far the most common way to install a metal roof.
3 install 1 4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1 4 purlins over the shingle roof.