How To

You can lay a new roof of asphalt shingles over one existing layer but not

You can lay a new roof of asphalt shingles over one existing layer but not more than one. Too many layers of shingles add a lot of weight to the roof and may cause it to sag or cave in.

By Yankee Magazine|Mar 24 2013|

You can lay a new roof of asphalt shingles over one existing layer but not more than one. Too many layers of shingles add a lot of weight to the roof and may cause it to sag or cave in.