Closet flange below floor
First of all, great forum! I am installing a new toilet, but the floor has been built up over the years- two different times with 3/4 inch plywood panels. The original flange was never raised when this was done. I stand about 6'4" tall and my aim has gotten pretty good over the years, but as I age, I'm afraid that will become a thing of the past. Anyway, I am adding another 1/4" plywood over old tile and new tile over that. As a result, the difference in height between the existing ABS flange and the new toilet outlet will be almost 2 inches! The existing ABS flange is installed over the 3" ABS soil pipe. My first choice to remedy the problem would be to purchase a deep throat flange and replace the old one. I have looked at every store in my area, including Lowe's, Ace, and Home Depot, but cannot find one. So, I bought a piece of 3" PVC (ASTMD 1785/2665), to connect to my existing soil pipe which is 3" ABS (D2261/N16H5) Schedule 40, using a 3" PVC coupling (Genova #70130) and an Oatey Twist-N-Set PVC flange(#43654). This flange with the attached gasket fits inside the new 3" PVC pipe, will this provide sufficient "flow" or should I use a flange that fits over the PVC, like the current flange does? I have read that I can connect the ABS with the PVC as long as I use the correct cement, true? Without pulling the toilet, I'm not sure if the PVC coupling will fit over the existing ABS soil pipe. I have access to the crawl space below, but hope that I can cut off the soil pipe somewhat close to even with a hacksaw or reciprocating saw. I have about 4 1/2" of soil pipe to play with between the existing flange and the tee connection which leads to the vent. I realize that I will have to cut out two pieces of 3/4" plywood to stack on top of each other to make up the difference in original floor height in order to attach the new flange to the floor. This is the only toilet in the house, so I will need to work quickly without any additional trips to the store. Would I be better off to continue to shop for a deep flange instead, leaving the soil pipe intact and just cut off the old ABS flange? I can send a picture of the existing flange and drain if that will help. Any assistance would be greatly appreciated, and I thank you
