You ll need longer nails for this part as you re driving through more layers of shingles.
Three layers of shingles on roof.
Bring the ridge edges together with a ridge capping layer.
According to the international existing building code homes can be re roofed one time by applying a second layer of roof shingles over the existing one but after that application begins to wear.
But contractors who spoke with angie s list say best practices call for stripping the roof down to the wood deck to inspect it before installing a new roof.
If there are really three layers of shingles it probably is far from a hidden issue.
Layers of shingles on top of each other shorten the life of the roof due to the newest layer sitting on an uneven lower surfaces.
Should be obvious from the street.
Having multiple layers of shingles is going to make your roof hotter because the heat gets trapped between the layers which could mean premature aging of the shingles.
Now you just have to decide whether to remove the existing roof shingles or recover the roof.
I haven t read a disclosure in a long time but if the previous owner had concealed anything it seems the new owner wouldn t yet know about the layers of roofing.
This is especially true if you ve overlayed your new shingles on top of warped shingles.
You can either use special shingles called ridge shingles or cut a number of regular shingles into 3 tabbed equal pieces and bend each so they fit snugly on the roof peak and nail them into place.
The best life will come from removing all the old layers down to roof boards or sheathing and then laying down the new roof on a well repaired flat surface.