When I was deciding the design of the garage, I wanted to match the garage roof to the roof of the house. The house had a hip roof, so the garage roof would be a hip roof. I had never built a roof. Based on the magazines and books I read, constructing a roof seemed straightforward. A gable roof consisted of a ridge board and rafters. However, with a hip roof you also have hip rafters and jack rafters. With a hip roof you have multiple angles and compound cuts. What was I thinking? A gable roof would have been so simpler. After the concrete fiasco and the wall debacle, a complicated roof layout was not what I wanted to jump into.
I will let you know in advance I will get a little too wordy trying to describe this portion of the garage building. But there are so many details building a roof, I wanted to share all the struggles we experienced.
Not knowing that the framing square was more than a straight edge, it was the very tool we needed to build the hip roof. Rehtorbym and I moved ahead to build the roof without it.
A roof rafter template was provided by the lumber company with the building materials. Unfortunately, it was just a template of the bird’s mouth.
We would start with the common rafters first to get the roof erected. The roof pitch was 4/12, or for every 12-inch horizontal run, there is a 4-inch vertical rise. The template had a 6-inch overhang, which was sufficient. We needed to determine the length of the rafter. Again, the framing square would have been so helpful. (I know I will lose a few readers with the math minutiae.) We determined the length by using the Pythagorean theory. The square root of 4 inch 2 x 12 inch2 = 12-5/8 inches. We used that measurement to multiply it by 11 (22 feet divided by two) from the bird’s mouth and subtracted half of the ridge board thickness. Since we knew the actual measurement was greater than 12-5/8”, we added an additional 1/4”. (Trust me, we had this figured out.) During my research on building a roof, I decided to purchase an angle finder tool. We would use this tool to determine the angle of our rafter cuts (instead of using the infamous framing square).
Using the template and my Craftsman® tape measure, we laid out our first two rafters. I climbed up on the step ladder and placed the rafter’s bird’s mouth on the top plate. I lined up the rafter to the stud below and I partially toe-nailed one nail into the rafter. Rehtorbym was on his step ladder in the middle of the garage holding up that rafter. I moved quickly to the other side with the step ladder and another rafter. Up the ladder I went and directed the rafter end to Rehtorbym. He grabbed the end and butted it against the other rafter end. Again, I put a nail into the rafter at the bird’s mouth. Rehtorbym nailed the rafters together to hold them in place.
We cut another 2 rafters and put those rafters in place several feet from the other two. We now wanted to slip the ridge board between the rafters. Since we had no idea how long the ridge board would be, we kept the ridge board at the length it was. As both of us were on our ladders with the ridge board in our hands, we separated the rafters and put the ridge board between them. We partially nailed the rafters to the ridge board. We came down off the ladders. Blocking the sun with our hands we looked up to check out our work. From one of the sides of the garage, the rafters did not seem to be straight. However, on the other side, the rafters appeared straight. We were baffled. After taking several measurements with my Craftsman® tape measure, we discovered the studs on both sides of the walls did not line up. Our carelessness of building our walls reared its ugly head. Since we did not completely nail down the rafters, we readjusted their locations on the top plate. Happy with the placement we nailed down the rafters.
We really wanted to figure out the hip rafters. We believe we needed to get those rafters in place before we finished with the remaining common rafters. We could not get our heads wrapped around the length of these hip rafters. As we scribbled math equations on paper, we were no further with an answer then when we started.
We decided to use the rafter template, the angle finder and an uncut 2 x 8 to get the length. We cut the bird’s mouth in the approximate location for a hip rafter leaving over 2 feet for an overhang. I positioned the rafter template and the hip rafter on the corner of the top plate. Using the angle finder, I placed the hip rafter at a 45-degree angle. On the ladder, Rehtorbym was hanging on to the end of the hip rafter. The ridge board was blocking our ability to accurately position the hip rafter. Rehtorbym stacked the hip rafter on the top edge of the ridge board. We did our best to line up the rafter as he marked it. We took down the rafter. With the Craftsman® circular saw he cut the hip rafter leaving several inches from his pencil mark. At least we were a little closer to the actual size.
We tried again to line up the rafter template and hip rafter on the garage. This time Rehtorbym verified his pencil mark. Using the edge of the ridge board as a reference, he traced a line on the hip rafter to create the angled cut. It looked good to him. He was ready to make the exact cut. However, this cut was a compound cut. Rehtorbym marked a line on his cut mark parallel to the line he created with the ridge board. He adjusted the Craftsman® circular saw blade to a 45-degree angle. As he commented, “Here we go,” he made the cut.
We were back on our ladders and Rehtorbym placed the hip rafter against the ridge board as I lined up the bird’s mouth end with the angle finder. We gave each other a grin. I think we had it figured out. We now needed to create 3 more hip rafters. We decided to leave the tail cut for later. We would cut it once we had all the rafters were installed. Using the one hip rafter as a template, I cut the other 3 rafters.
Now that we had the hip rafters done, we could cut the ridge board to the correct length. After we cut the ridge board, we nailed down the hip rafters. What we did not know was the jack rafters would be an adventure.
We could use the rafter template to cut the tail and bird’s mouths of the jack rafters. Lining up the rafters to the hip rafter, we marked and cut the jack rafters. The jack rafters should have been the same size of the corresponding jack rafters on the other side of the hip rafter. However, that was not the case. Fortunately, we did not go crazy and cut all the jack rafters at once. The first pair of jack rafters did not line up. One needed to be longer than the other even though both were 16 inches from the corner. As you would guess, the hip rafters were not at the correct angle. We again were to far into the construction of the roof to turn back now. We did not think it made sense to dismantle the hip rafters or replace a possibly short ridge board. We would adjust the jack rafters as we went.
We continued with the building of the roof. We tried to get the rafters at 16 inches on center and centered on a stud. That effort was futile. We adjusted the rafters accordingly and completed the installation of the rafters. Now the plywood roofing.
With plywood length of 96 inches divisible by 16 inches, the sheet edges should have landed in the middle of the rafters. The laying of the roof sheeting required many cuts as many sheets missed their mark. The rafters ranged from 15 inches to 17 inches on center and some were not perfectly straight.
Once we were done with the plywood, I needed to cut the extended tails of the hip rafters. I marked the extended tails of the hip rafters using a string line. In the process I noticed the rafter tails were not even on all four sides. I would fix that issue when I install the fascia board. I trimmed the hip rafters with my Craftsman® circular saw.
I completed the rest of the work by myself as Rehtorbym started school. He would stop by now and again to check out the progress.