View Full Version : Toilet Drain/Joist Clearance
08-25-2012, 05:38 PM
Is there a minimum clearance requirement between a joist and a toilet drain opening? I read something about, I think, 3" from the center of the drain to a joist. I'd like to sister the bad joist in the attached pic. If my calculations are correct, doing this will leave me about 1/2" from the edge of a properly-centered 5" drain hole in the subfloor to the new sister.
08-25-2012, 06:26 PM
From a practical viewpoint, most toilet flanges are a cone, so they flare out from the pipe. Thus, if the joist was right next to the pipe, you may not be able to slide the flange on while gluing it in place - at least you may not be able to slide it all the way in. Now, this is often more of an issue with a 3" pipe than a 4" pipe where you could use an internal flange.
Don't know if there's an actual code issue here, but more of a practical issue on what will fit.
08-25-2012, 07:12 PM
I don't see much joist left in that photo, I hope it wasn't you who went crazy with a sawzall.