Quote:
Originally Posted by Acres per Second
The only reason I can't answer your question is that I've always done my own re-roofing! 
However, both of us could have learned from my Winnipesaukee neighbor: Thirty years ago, when he thought it was time to re-roof, he just put new roofing materials over the old roof!  (No removal of the old materials).
I thought that was highly unusual, but a NH roofer told me it's not at all unusual for old roofs to be left intact for re-roofing.  |
It's extremely common to reshingle a roof and leave the old roof in place. I wouldn't say its done as often as removing the old roofing materials but yes, it's quite common. Some people are of the opinion it acts as another layer of insulation.