How to Cut a Roof for a Carport
Building a carport on your own is not only a rewarding process, but is something most novice handymen can handle. The process is simple, and requires little more than basic tools, lumber, and common sense. Here, we will be focusing on how to design and build the roof of your carport.
Step 1 – Planning
As the age old carpenter’s advice goes, measure twice and cut once. You’ll have to do a bit of math to determine the size of your trusses, if you want a double pitched roof. To determine the length of your trusses, measure how long they will be horizontally (if you want trusses that peak at the middle of your carport, simply measure from the edge to the middle). Then measure how high you want it. Square both of the numbers and add them, then find the square root of that number. This will be how long your trusses are.
For example, if you want them elevated by 2 feet, and it is 6 feet from the edge to the middle, you would add the square of 6 (which is 36) to the square of 2 (which is 4), giving you 40. Then find the square root of 40, which is between 6.32 feet and 6.33 feet; that is how long the top sides of your trusses should be.
Step 2 – Trusses
Roof trusses are the triangular framing on which the roof will sit. Cut 2 boards to the length you came to in step one, connected at one end by a metal bracket, and attach those two ends to a third piece the length of your entire roof, again using metal brackets. Use 4 more diagonal support boards attached in the shape of a W; the middle two boards (or the middle point of the W), will meet at the top corner of your triangle.
Build at least two of these (one for each end) and more if the width of your carport calls for it, then make marks along their bottoms every 2 feet; this is where you will bolt it to your carport.
Step 3 – Rafters
For your rafters, use lag bolts to attach 2x6 boards all around the top of your posts. Using joist hangers, attach 2x6 rafters spaced between your 2x6 boards. Use a 2x4 or 2x6 bolted flat around the top edge of your rafters on all 4 sides; this is your top plate.
Step 4 – Attaching Trusses and Plywood
Using the marks you made earlier, attach the trusses to your top plate and rafters. Once the trusses are in place, you can begin nailing your plywood in place on top of the trusses, using L brackets if necessary to attach to them to the trusses, and H brackets to attach sections of plywood side by side.
Your roof is more or less done at this point. All that is left is painting for the sides, and shingles on top.