It provides a solid flat surface to attach the new metal roof to it creates an air gap between the back of the metal and the shingle roof which allows for airflow.
Proper installation of metal roofing over shingles.
Use furring strips to build a slat board on the roof then mount the steel sheets to the slat board.
Remove the old roofing.
However you should only install a metal roof over shingles if you have less than four layers of shingles on the roof.
Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps.
Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails.
First because the frame is screwed directly to the rafters and the interlocked shingles are screwed to the frame the roof can withstand winds of up to 120 mph without damage.
Building officials in some areas will only allow a re roof over one layer of shingles while officials in other places may allow you to place the roof over two layers of shingles.
This framework has three big advantages.
Metal roofing is resistant to fire rot and termites.
A metal roof is an alternative to a shingle covered roof but a metal roof can actually be installed over shingles.
Yes you can install a metal roof over shingles.
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.
Although you can install corrugated metal roofing over shingles for the best foundation it is recommended that all the old roofing be removed.
Work at a comfortable steady pace trying not to rip up or carry off too much old roofing at once.
Otherwise you will need to remove the shingles.
However you ll want to check with your local building department before you make any decisions.
Yes you can and by doing so you save in the labor and hassle of tearing off the old roof and you won t be contributing to filling our landfills.
Installing the metal roofing over 1x4 s allows the ability to also install additional insulation under the metal roof.
Better steel shingle systems like the one shown install over a framework of 2x2s.
Another added benefit is that the layers of your old roof will further insulate your home.
In a standing seam roof long single panels run vertically all the way from the eave to the ridge.
Most metal shingles will be attached to the roof using metal shingle.