View Full Version : comode installation on concrete

05-14-2012, 07:44 PM
Recently acquired a home with a stubbed in bath in the full basement. I would like to install a comode and sink in this bath. I have never attempted an installation like this. I have installed a couple that were installed on a wooden floor....How do you attach the comode to the concrete floor?

05-14-2012, 08:38 PM
What size is the pipe for the toilet? If it is 4" ID and plastic, then you can cement in a toilet flange. It will have the normal anchors to hold the toilet, and you should anchor the ring of the flange to the floor. Note, the flange is designed to install on TOP of the FINISHED flooring. The flange will accept the bolts to hold the toilet, then, typically, you caulk around the front 3/4 of the base, which both seals it and helps to hold it in place as well.

If the ID of the pipe is 3", then you need to crack some concrete so you can install a flange around the outside of the pipe.

Gary Swart
05-14-2012, 10:29 PM
There are a couple of ways to anchor a flange (or anything else) to concrete. Some folks prefer Tapcon bolts, and they do work. To my way of thinking however, they are sometimes difficult to install. I drill a 5/16 hole in the concrete with a rotary hammer drill then 3/8 lead sleeves into the holes. Then #12 sheet metal screws into the sleeves. For a toilet, I use stainless steel screws. In addition to toilet flanges, I have attached 2x4s to floors and walls, electric outlet boxes, and pipe clamps this way and have never had any of these come loose.