If you are ever coming into London from Sarnia on #22, the Lowes at #22/Hyde Park has a good selection of PVC, including unions, ball valves, flex pvc, etc. They don't have PVC gate valves though. Rona in London carries more PVC products than the used to (in competition to Lowe's in my opinion), but I rarely go there. I hit up the TSC on Hyde Park as well as it is closest to my house, they have pretty good selection too but sometimes they are low on stock. Typically, 98% of the time I can get my plumbing supplies at Lowes/TSC. There must be a TSC in both Sarnia and Chatham?