Then nail shingles on the new roof and exposed areas of the old roof.
How to roof overlapping gables.
If you align the shingle.
The majority of the metal sheets will go onto the roof whole and intact.
You want to lay the shingles from the bottom to the top of the valley.
Fold new shingles over the new valley onto the old roof overlapping by at least a foot.
If your eave is one straight length then pick an end and work to the other.
Finish your gable roof addition tie in by installing siding to match the existing house and fascia and trim boards at eaves and edges.
As you near the edges of the roof or any points where the roof has gables you may need to cut the sheets to custom fit the space.
Use a tin snips to cut the drip edge to size.
The next one goes on the low side.
Use cap shingles or 12 inch shingle pieces to overlap the peaks.
Tips on how to install shingles on a straight gable roof.
Installing asphalt shingles on a basic gable roof is one of the most straight forward of all roofing projects.
Staple roofing paper on both gables with a construction stapler and install shingles.
Then your first shingle goes on the side you are going to cut.
Weave and cut the valley on the highest side of the roof.
Start at the bottom side of the gable and overlap the sections of drip edge a few inches as you work your way up the roof see figure a.
Start by overlapping a starter from both sides of the valley at the bottom.
Start by applying the drip edge to the eaves of your roof.
Put one shingle across the valley from the left the next row overlapping from the right for instance.