We’re back with a few more tips and tricks for installing cedar shingles.
Between the shingles and the structure, we’ve built up what is called skip-sheating, described in an earlier post. As the horizontal 1-×-4-in boards reach the edge of the roof, they extend 1/4 in over the last 2-×-4-in board. This lets air flow in and out to help dry out the shingles after rain. An aluminum drip edge (white in this picture) is installed over this juncture to direct any water out over the edge instead of letting it run back under the shingles.
In some places, brackets need to be installed. In our case, we will be mounting a solar water heating unit, so we put in L-brackets. It is easiest to do this while installing the shingles as opposed to later. In this case, the bracket is placed on top of a square of aluminum flashing. The protruding end of the bracket is just at a level below the next shingle row. Another piece of aluminum is placed over the bracket after installation and then further courses of shingles are installed. This helps protect the bracket and screw holes from getting any water damage.
At the lower edge of the roof, we’ve got gutters. The supports are metal strips nailed onto the sheathing. Next comes a 6-in straight drip edge which directs the water out, away from the roof surface and into the gutter. On top of that comes a roll of tar paper. While the drip edge extended out 1 in from the roof edge, the tar paper is flush with that edge (thus the aluminum sticks out about an inch below the tar paper). Shingles are installed over this with a 1-1/2-in overhang to let the water drip free into the gutters instead of running down the side of the fascia board below.
In the valleys (where two planes of the roof meet), flashing is laid over a layer of tar paper. Then shingles are cut to match the angle. A notch the length of the exposure is taken out, allowing it to sit flush against a clean edge. Underneath the edge, the narrowest shingles are angled to help guide the water to run down the valley instead of under the shingles.
The end result can turn out quite nicely. Taking a bit of extra time to keep lines straight pays off in the final view, as seen below in the picture of our finished garage.