A canvas awning over a deck, patio or camper makes hot days bearable, protecting those beneath from intense sunlight and harsh heat. A hole or tear in a canvas awning can ruin the awning's ability to shield you from the sun and rain, leaving you exposed to the elements. A tear also represents a weak point in the canvas, and when one tear has formed, more may be on the way if you cannot repair it first in order to seal and protect the canvas from further damage.
Measure the damaged area of the awning. Cut a piece of canvas that will extend beyond the damaged area by at least 2 inches on all sides. This will allow you to patch the canvas and provide reinforcement for the damaged area.
Line up the patch and pin it in place with sewing pins. Thread a sewing awl, which is essentially an extra-strong sewing needle. Follow specific product instructions for threading directions. In general, you will need to remove the head of the awl and insert the spool of thread.
Place your forefinger on the reel of the awl to hold the string firmly in place. Insert the awl through the canvas so that the needle protrudes from the back side. Grasp the thread with your other hand and pull out enough thread to measure twice the distance you intend to sew.
Hold the thread securely in place beneath the canvas and pull the awl back through the fabric. Move forward the distance of one stitch and push the awl through the surface again, without holding the reel this time. Pull the thread slightly away from the needle, forming a loop.
Thread the original long piece of string you pulled through the loop you just made, forming a knot. Hold the bottom thread in place and pull the awl back through the same hole, tightening the first stitch.
Repeat stitching all the way around your canvas patch. This heavy-duty stitching will help to secure the patch in place despite the stress of the awning.
Seal all seams on the patch with liquid stitching adhesive, which you can purchase at crafting supply stores.
Find extra canvas, strong thread and awls at outdoor supply shops or hardware and home improvement retailers. You may want to remove the awning from its suspended position to make sewing the canvas easier.