2 layers plus metal

Home owner installed a metal roof over 2 layers of existing asphalt shingles. How would you guys write it up? Is it a concern like 3 layers would be or is it OK?


Isn’t that three layers?

Hi Scott,
What is there for roof frame?

It’s a small house. The framing is 2x8 rafter with plywood sheathing and 2x4 collar ties at about a 6 pitch.

Other than the metal not sitting very square, the roof does not currently appear to sag, but the wood starter drip shingles do have some rot in them.


Do you have any pictures?

This is about the best I can give you.

Hope it helps.





No botom drip edge to divert water. what is to keep the wind from blowing rain & snow in along the rake edge, & what is the botom 3/4 board for anyway? Improper installation of roofing material. Write it up. Also most manufacturers do not allow a 3rd layer. I’d sure point it out.

Call for a licensed roofing contractor

Do they not call for permits for roofing in New Hampshire??

Scott, Go to www.abcmetalroofing.com and take a look at their installation instructions.

I would never install a metal roof over two layers of shingles, also there is no drip cap under the panels near the eaves and no rake trim.

The excessive weight of all of these roof coverings should be a concern.

it looks like they put 1x3 strapping over the asphalt shingles, paralell to the ridge and then fastened the metal roofing to the strapping. see the row of fasteners? those are perpendicular to the rafters below.

typically only two layers of asphalt shingles are accepted on a roof, due to weight. call the local bldng inspector and ask what the local code is.

of course, up here we get alot of blue tarp roofs. it’s like our state flag.:stuck_out_tongue: