I recently found out that that the floor below the toilet was rotting due to a leaky toilet seal. I removed the tile, cement board and the rotten wood. I am now in the process of replacing everything. My question is do I need to cut the pvc flange off and start replumbing? I have included a picture and would appreciate guidance on the next step. I was thinking that I would cut the 3 inch pvc pipe, add a collar and attach a new 90 degree and then set the flange once the floor and subfloor are replaced. Is there an easier way to do this?

You have 2 ways to go:

1. Cut Closet ring about 4" below existing floor. Glue in new 3" PVC coupling and piece of 3" PVC pipe that will end up to be higher than the finished floor. Lay your subfloor ( cut hole for the pipe and slip new subfloor over it ), nail it. Then cut off pipe level with the floor. Buy closet ring that slips over the pipe and glue it in. Secure with brass screws to the subfloor.

2. Leave it as shown. Add blocks under each cut. Also, add block in the middle of the square. Cut new ply to fit the void in the floor. Cut 3 3/8" opening for existing toilet pipe ( this hole will be smaller than the Closet Ring ). Take skill saw and cut the new piece of subfloor right in the middle. Put one half on one side ( slide under existing closet ring ) and than put the other half from the other side. All cuts should be on blocks to prevent flexing.

I prefer 1st method. I like on piece of ply under my toilet.

Milo

I understand what your saying about option one. The problem is that the closet ring is attached to a 90 degree elbow which is connected to the 3 inch horizontal pipe. So basically I don't have the 4 inches to do what your suggesting. So do you think it would be OK to cut the horizontal pipe, insert a collar and then basically just rebuild what is there? The part I am most concerned about is the collar being set on a horizontal run. Will that remain water tight over time.

Cut pipe on horizontal (hold pipe firmly while cutting it)... install coupling and new elbow (level from side to side). The coupling will work perfectly on the horizontal... PROMISE! Install a 12" dry fit (don't cement) piece of pipe for now and place into the elbow.

Install new floor leaving a 5" hole for the pipe to go through. Once the finish floor is installed remove the dry fit pipe and place the new closet flange into the hole... measure distance of pipe needed between elbow and new flange to sit on the finish floor. Cut the piece and cement it into the flange first... let dry a bit... then prime/cement the pipe/flange into the elbow.

Line up flange so the closet bolts will be where they need to go and then drill and anchor in the new flange through the finish floor.

Should do it... ;)

Mark

PS: Be sure to use a primer and cement on all fittings.