Installing Metal Roofing Over Cedar Shakes

We get asked this question all the time.

Installing metal roofing over cedar shakes.

Make a slat board base on top of the shingles. 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. If you have an open valley install new w shape metal or vinyl valley flashing to fit directly over the old flashing. Install the metal edging.

Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps. Make sure roof is square. Use 1 1 4 inch. As long as the plywood under the shingle roof is in good condition this way can provide many benefits.

Can i install a new metal roof over shingles. Most metal shingles will be attached to the roof using metal shingle. You will need to lay some 1 by 4 inch pine boards lengthwise every two feet on your roof. But now that i said that i would tell you that if it was my house i probably would and the reason is i don t want to have all those old shingles under the roof.

Check with your local building official for exact specifications in your area. Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails. Attach it by driving nails into the outside edges only. Install your metal edging around the perimeter of your roof.

The metal will be attached to at least 3 4 purlin and 1 2 plywood instead of just 1 2 plywood which should make the overall roofing system stronger. The purlins give the installer a flat surface to install the metal roofing panels down to without the irregularities a shingle provides. How to install a metal roof over shingles. 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.

The cssb recommends using an 18 wide strip of no 30 astm d226 type ll or astm d4869 type lv roofing felt laid over the top portion of the shakes and extending on to the sheathing.