Toilet drain a little low

[Sethamin]

So I'm redoing my bathroom, and I roughed in the new toilet drain about 1" above the subfloor, figuring that the concrete backer board + thinset bed + tile would put the finished floor just level with the drain. Unfortunately, I didn't account for the fact that the floor was significantly out of level, and after putting down the backer board and leveling compound, the drain is already flush. Once I put down thinset and tile (probably 1/8" and 3/8" thick, respectively), the drain will be about 1/2" below the finished floor.

Is this a significant problem? I figure that as long as there's enough overlapping PVC between the closet flange and the drain, I should still get a solid solvent weld connection. Is that an accurate assessment? And how much is "enough" - I'm thinking around 2 inches or so should ensure a sufficiently good join. I could still cut the whole thing out and replace the closet bend on upwards, but I'd obviously rather avoid that if possible.

 

[Gary Swart]

If you can get 2" into the closet bend, that will be way plenty. Be sure you secure the flange through the finished floor and into the sub floor. This can be a problem for a DIY because you will need to drill holes through the tile for the screws and this requires a special drill bit. If possible, you can cut a notch or V where the screws will go and avoid the need to drill. For the toilets I've installed on a new floor, I used #12 stainless steel screws. SS may not really have been necessary, but for a few cents more, it seemed to me to be worth it.

 

[Sponsor]

 

[Asktom]

The screws should be brass or stainless. If you are having inspection it is easier for inspector to see you used the correct material if they are brass.