Closet flange unsupported
The flange MUST be in contact with the floor, never try to use thinset or concrete or any other filler to do this as it will crumble over time and cause a leak. When you install the cement board locate the flange on the cement board, next make a circle the same size as the pipe (Usually 3-5/8" or 4-5/8" for outside dimentions)
Next cut the cement board straight across the board so it passes through the center of the circle you just made. Now cut out the 2 semi circles. Remove the old screws, insert the cement board sliding it under the flange. Next install the second one the same way. Secure flange with new screws. After fastening the cement board down use tape and mud to seal the cut you made. This taping can also be done by the tile setter. If you do not want to do all that then use 2 plywood semi circles cut from plywood, remove the old screws, install the semi circles under the flange and secure with new screws. As for the above response by Davefoc, if you have a flange that is flush with the subfloor, then has cement board and tile just use a jumbo deep seal and a regular wax ring. 2 tips here. 1 is if you can not secure flange because of any reason using screws, then drill through the floor where the screws were, use long bolts with a pan head on it (A regular screwdriver slot in the top) along with a washer and nut underneath. 2 when setting any toilet set wax rings, next set toilet onto wax rings over bolts. DO NOT PUSH DOWN, rather stop and look to see if the toilet is being held up off the floor. If it is and you must use some force to push it down, then ther is enough wax. If the toilet hits the finished floor without forcing it down, then you need more. Always add a regular ring on top of another as 2 deep seals will not work togethet. 1 deep seal, then 1 or 2 regular rings is ok.
Last edited by USP45; 01-02-2008 at 03:21 PM.