We have a 10x10 ft gazebo out on our deck all summer. However when it rains water will pool on the canvas top even with the drain holes that are supposed to prevent this. These are intended to prevent the low spots from collecting too much water.

I used a 1/4" dowel inserted into the hole that con be cut to any desired length (8 inch lengths pictured). Also I used a 1-1/2 in. 10/32 counter sunk screw with a matching thumbscrew to hold it in place.