The Upholstery Forum

I'm making a 20' carport cover by sewing 60" wide panels together. The material is a 100% polyester canvas and I am using Sailrite PTFE lifetime thread. The cover has a 10-degree slope for the water to run off and it will run to a drain hole in the material on the low end so the pressure of standing water is eliminated.
Do you think a single line of sewing is adequate to join the panels?
Thanks
Joel

I think I would fold the seam allowances from both pieces to one side and do a single reinforced top stitch. If anything it will make the seam lay nice and flat. I've not made an awing cover yet but I think they make a seam tape to go between the two pieces to help with water seeping through.

Top stitching will help with water seepage as well as reinforcement. Which direction will your seams be oriented? Up the slope or across? If they are across, be sure to shingle your top stitch towards the peak. What i mean is when you top stitch, fold your seam allowance toward the peak so when water runs down it doesn't get caught in the seam. This means each side will be top stitched opposite of each other. If your seams go up the slope and over, it matters less which direction you shingle it, in that case i'd do them all the same way

Yeah same here. Single reinforced seam in that application would be best.