I'm having a heck of a time getting the right combination of pipes to fit my existing chimney. I have an 8" clay(?) pipe going from the basement out through the foundation into the chimney. I ordered what I thought I needed from Home Depot. It wasn't right. I called DuraVent themselves and they suggested a collar to solve my problem. Now it hasn't come yet but I'm not convinced it's going to be the right part. Other than just waiting for my next package to arrive, does anyone have any ideas? Thanks!