But back to the roof.
The first piece I put up was the 4-foot-tall beam supporting the ridge beam. The ridge beam supports the rafters. Tall beams (I-beams) are very stiff because the flange strength is proportional to the cube of the distance from the neutral axis (for symmetrical beams, that's half the beam height). In this case, the beam's "web" is a sheet of 5/8" plywood, and the flanges are, on the bottom, a 2x4 ceiling joist, and on the top, the 2x8 ridge beam. What matters is that it's unconventional construction but hugely strong.
In the photo above the top "flange" (the ridge beam) is not yet in place. The large piece of plywood lying on the deck (above) will position the ridge beam. It was cut out from a full-scale layout on my garage floor (derived from the plans I had drawn).
That piece of plywood is the first piece of the center section of the front wall; it will be securely fastened to that main plywood beam with screws and urethane glue. I used all 19/32" plywood (about 5/8") which is pretty heavy, and trying to lift it into place and fastening it at the same time would be folly, without some temporary cleats to hold it in place (or else it would surely fall to the ground).
Looked like this when it was in place:
The next step was to attach the front rafters, but before that I had to lay out the rafters full scale on my garage floor (as part of the earlier full-size layout). I then cut the angle on the top of one rafter and the notch on the other end, and used this one rafter as a template for cutting all the others. It pays to be very precise when making this template.
The ridge beam is set in the notch in the plywood, and then the rafters at the front go on first.
Once this rafter pair is on, I cut and installed the notched studs for the upper front wall (cutting the notches using my table saw).
Then the other rafters can go on. I marked their position on the ridge beam beforehand, and on the top plates of the side walls as well, so they went on quickly (3" screws and nails).
I cut the rafters long, and cut them off at the ends after they were installed, using a straight edge across the top of all of them, and then a level to plumb a vertical line on each one. I then cut them off with a circular saw. The idea is for the 2x6 sub-fascia to line up perfectly with the end of each rafter. I beveled the top of those 2x6s at the same 22˚ rafter angle.
I screwed another 2x4 to the wall below the rafters, the bottom of which was at the same level as the 2x6 tying the rafter ends together. The soffit on the sides of the roof will then be fastened to these two pieces of wood.
These two pieces of wood also extend out from the front wall to support the "flying" rafters, which creates the roof overhang. The ridge beam also extends out the same amount (about 16"). The first rafter pair I installed at the front of the wall were 2x8s (7.5" wide). I fastened another pair of 2x6 rafters directly to these; the soffit at the front is nailed into the underside of this second 2x6 rafter (the plywood front was fastened to the bottom 2" of the 2x8 that extended below the 2x6). (Forgot to take a photo to illustrate.)
I installed 2x6 braces/spacers on 16" centers between the inner 2x6 rafter and the "flying" outer 2x6 rafter. These are absolutely essential to give the overhang its strength, combined with the plywood on the roof (the upper flange) and the soffit (lower flange). It forms a very strong box structure.
The 2x6 structural members on the periphery of the overhangs are not pretty. On the outside of these goes 1x8 finished boards. Besides presenting a nice smooth surface, these boards extend above the 2x6s to contain the plywood roof decking, and extend below to hide the edges of the soffit.
I beveled the tops of the 1x8 fascia boards to the same 22˚ roof angle. Installing the plywood then becomes easy. Butt the edges against the inside of the fascia board — no worries about it sliding out of position.
But before I could nail down the plywood, I had to get the heavy sheets up on the roof, by myself. What worked quite well was to slide the plywood up my fiberglass extension ladder, placed at a relatively low angle against the roof.
While the bottom of the rafters that were over the new part of the garage were fastened to the top of the new extended garage wall, there was no convenient place to fasten them on the angled old roof, so I beveled long 2x6s and placed them to correctly locate the bottom end of the rafters for that part of the new roof (where the old and new fascias met).
Rafters could then be installed (not notched at the bottom end, but angled appropriately). Again, I installed 2x6 spacers between adjacent rafters, which distribute point loads on the roof to adjacent rafters (making for a much stronger roof). Incidentally, the old roof was constructed using 2x4 trusses spaced on 24" centers, with thin plywood (closer to 3/8"), so it tends to be a little springy when walking on it. By contrast, my new roof has 2x6 rafters spaced on 16" centers with 5/8" plywood, so it's solid.
Before putting the plywood on, I also took the opportunity to install attic insulation on top of the new ceiling, as that part of the attic would not realistically be accessible after the roof is on. You can see some of the white insulation already installed in the above photo.
So the plywood and rafters go on:
And with all the plywood on:
And from the front:
Next step is to strip the remaining shingles off the front part of the garage roof, then apply new shingles (after all the preliminaries (roofing felt, drip edge, starter course, etc.). And then repeat for the back of the garage roof. Not going to go real fast with the hot weather headed my way.
After that, apply stucco to the walls. Then finish the inside of the garage. None of these projects is trivial. But they'll all get done if I keep plugging away. Sigh.
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