Yes you can install a metal roof over shingles.
Installing metal roof panels over shingles.
This is what it looks like when you install a steel shingle roof system over an existing asphalt shingle roof.
This method has its benefits as well.
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.
However you ll want to check with your local building department before you make any decisions.
Install metal roofing sheets.
The second way to install a metal roof over a shingle roof is with the use of purlins or battens.
Metal roofing sheets have to be installed one at a time.
In a standing seam roof long single panels run vertically all the way from the eave to the ridge.
Use 1 4 inch metal wood screws to attach the metal sheets to the wood slat board base.
Place a sheet from top to bottom on a section of the roof.
Most metal shingles will be attached to the roof using metal shingle.
Venting the eaves to vent the roof holes are cut in the old roof above the soffit which pulls air through the soffit vents underneath.
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.
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.