I am replacing a toilet and have to deal with a broken ABS 4x3 flange. One of the slots is cracked and won't hold a bolt. I would like to use a spanner flange to bridge the gap, but I am unable to place it below the ABS flange due to lack of room between the bottom of the flange and the top of the tile. I could probably get the flange to slide in, but not with a bolt. Also, the flange is nailed at angles to the floor, so I cannot easily raise it to accommodate the spanner flange. Because the nails are in the way, I would also have to trim the spanner flange down a bit and drill new screw holes both in it and in the ABS flange.

So….my question is whether I can safely just put the spanner flange on top of the ABS flange and secure it with screws. The instructions of the one I bought (https://www.homedepot.ca/en/home/p.1000450722.html) do not mention this as a possibility, though I have seen videos and photos online that do put it on top. My only real concern would be the impact on the wax seal, but I think the ring would be slightly interior of the spanner flange.

Failing this, my other option might be to buy a closet screw (Toilet Replacement Parts | Toilet Tank | Fix Toilet | 3 1/2" Toilet Bowl to Floor Screws (http://www.fluidmaster.com/our-products/toilet-parts/3-1-2-bowl-to-floor-screws.html)) and secure one side of the bowl directly to the floor, like an old 4 bolt toilet. The subfloor is in good shape. If anyone has used this method I would be interested in hearing about it.

The flange it what you need. Screw it down, the wax ring cone should be inside the opening. Very common repair with PVC flanges.

Purchase metal overlay repair ring, screw it to the floor ( concrete or wood ), and attach bolts to the new ring. Install wax rings and toilet as usual

There are many different types and configurations repair rings. I am enclosing visual of two such rings

Hope it helps

Milo

Normal repair is to place the repair flange on top of the old , broken or damage flange.

Does not affect the use of the wax ring.

Also perfectly acceptable to use the floor screws if the subfloor is solid. All you need to do is be able to secure the toilet to the floor so that it doesn't move.