Beginning to frame the roof

Last Sunday (2/10/08) I started on the roof. The first step is framing the rafters with the 10" insulation space above the ceiling boards. I'm using lumber that I milled, lumber I salvaged from an old mobile home I demolished, and boards from a pallet company.

In this photo, seven of the rafters are attached to the timber frame. This is on the back of the house, and each rafter needs to be about 14' 6" long. They are made up of two 2x3s I milled and three 10" long sections of 2x6 to hold them up the required distance. The 2x6s are nailed to some vertical strapping and are also toe-nailed into the purlins on the timber frame. I also nailed a 3/8" to 1/2" thick pallet board to the two rafter boards at the joint to help with strength and rigidity. I will add some diagonal braces later to help ensure they all stay rigidly in place. The OSB I'll sheet the roof with will also impart rigidity, tying it all together. That will be sometime in the next couple of weeks, if the weather allows.

Here's a closer view of the same thing. The vertical strapping I used came from the pallet company, also. Originally they were approximately 2" by 4", but I ripped them to 2" wide. They were mostly 4 feet long with some 3 footers. At this width when I secure them to the roof, it places the rafter right above them, simplifying the layout. The rafters are on 2' centers.

The back of the roof is easier to work on because of its 3:12 slope. The front is 8:12, which I can walk on without slipping, but it still makes me nervous. I don't relish the thought of sliding off. So, I've nailed steps of 18" long 1x1s over the purlins for added safety while installing the rafters on the front. The front rafters are built the same way as the ones on the back of the house. They are 19' 8" long and consist of either two lengths of 2x3 or three lengths of 2x4. The 2x4s were ceiling joists in an old mobile home in their previous life. In their original form, they are 9' 6" long, but they taper on one side near the end so that they gave the mobile home roof a rounded slope. I cut most of the taper out when building my rafters. Yes, we had a little bit of snow this week. I waited until it melted before climbing up and working on the roof.

In this view from the east end of the house, you can see the profile for the rafters. Also, you can see the overhang on the back of the house. The straw bales will be stacked to the rafters. So, the three feet that the rafters on the back stick out allows for covering the straw bales and the wood siding I'll put on as well as allowing for at least a one foot overhang. The rafters on the front only overhang the frame by 20". The straw bales will be stacked to the rafters, but the porch roof will tie in to the main roof at that point. So, there is no need for more overhang on the front.

Here you can see the back of the house with my progress there. I was able to get 14 of the 19 rafters on the back so far. You can also see the cupola. I roofed it last week and framed it for the windows. It's wrapped with a blue tarp to keep the rain out for now. I'll be purchasing and installing the windows before getting the metal roof on the whole house. I kind of figure that the metal on the front of the roof will be a little slick for working on. I'll have to for some things, I'm sure, though.


I took this photo yesterday evening, showing my progress so far. I'll start on the near side of the front roof next.