We are having a bathroom remodeled and there is a problem with the toilet flange. The original flange was set in the concrete slab, and was both too low and leaned to one side, which caused recurring leaks. We had hoped to have it replaced as part of the remodel, but have run into some issues. It turns out the reason the original flange was tilted is that the drain pipe that it is connected to is not vertical. It leans about 4 degrees to one side causing the flange to lean with it. The contractor has ground the flange down to somewhat flush with the concrete slab but we are having trouble coming to agreement on where to go from here.
We see three possible paths going forward, and each of them has drawbacks.
Option 1 - Chisel out the old flange and set a new one. This was our original plan, but I'm concerned it won't work with the leaning drain pipe. When I slide a standard (internal) PVC flange inside the existing flange it leans significantly just like the old one did. Is there a way to set a flange level on a pipe with this much lean?
Option 2 - Use a "repair" flange like a Sioux Chief PushTite or Oatey Twist-N-Set. This would be easy to install and might be adjustable enough to sit level despite the crooked drain pipe. It would need something (what?) underneath it to stabilize it. However, this feels like a poor long-term solution. The rubber seals will inevitable compress and I fear they would not remain gas/water tight over time. This is of particular concern on the ground floor as the toilet would be the first place in the house that water would back up if there was a clog in the main house drain.
Option 3 - Cut the slab and install a new drain pipe and flange. This might be the best long-term solution, but would be very difficult. The slab is over 8 inches thick and is 50 years old. Almost half of the slab sits on unstable fill dirt on a steep hill so we would prefer not to stress it or risk creating cracks using a jackhammer.
We are open to suggestions. I can provide more photos if needed.
We see three possible paths going forward, and each of them has drawbacks.
Option 1 - Chisel out the old flange and set a new one. This was our original plan, but I'm concerned it won't work with the leaning drain pipe. When I slide a standard (internal) PVC flange inside the existing flange it leans significantly just like the old one did. Is there a way to set a flange level on a pipe with this much lean?
Option 2 - Use a "repair" flange like a Sioux Chief PushTite or Oatey Twist-N-Set. This would be easy to install and might be adjustable enough to sit level despite the crooked drain pipe. It would need something (what?) underneath it to stabilize it. However, this feels like a poor long-term solution. The rubber seals will inevitable compress and I fear they would not remain gas/water tight over time. This is of particular concern on the ground floor as the toilet would be the first place in the house that water would back up if there was a clog in the main house drain.
Option 3 - Cut the slab and install a new drain pipe and flange. This might be the best long-term solution, but would be very difficult. The slab is over 8 inches thick and is 50 years old. Almost half of the slab sits on unstable fill dirt on a steep hill so we would prefer not to stress it or risk creating cracks using a jackhammer.
We are open to suggestions. I can provide more photos if needed.
