When we bought the home, it had a roughed in place for a commode. There is a sewage pump installed in the basement floor.

The roughed in place had a red cap in the basement floor and we were told that is were a commode could be placed. I took off the cap. Under it, there was a 4" diameter iron (open) pipe surrounded by an air gap of 1 inch all around the pipe.

When I look for flanges in the stores, all of them have screw holes right were the air gap is located around the 4 inch pipe. So, my question is, what is the correct way of installing a flange for a commode in the cement floor of a basement.

I did temporarily solve this by gently wedging wood between the pipe and the concrete and then screwing into the wood to hold the flange. I know this is very wrong, but I did want to see if the commode would work with the sewage pump, and it works great.

I know nothing about maintaining a sewage pump. The one we have has had very little use and is nearly new. We are concerned about what can and can't be flushed down the toilet.
Thanks, Synder

Lol, the old guys are going to love you. They like that air gap. You are supposed to lead a 4" cast iron flange on that 4"cast iron pipe. I would do it differently. Is the pipe flush or slightly under the level of the floor? I would clean out the debris from that air gap and fill it full of hydraulic cement then install a pvc compression flange with the 3 allen screws type on the inside and tighten those screws then using papcons or plastic anchors I would secure the flange to the floor.
What can and can not be flushed into the sump basin? I personally would not use 2 ply paper. And anything that will bind up the pump. Rags, rocks, plastic toys, the like.

doug238,
Thanks for you answer but what do you mean by "lead a 4" cast iron flange on the 4" cast iron pipe???

I like your idea of using hydrolic cement around the pipe. Do you mean that I should sink the papcons (?) in the wet cement and then after the cement has cured, secure the flange to the hydrolic cement??

When that pump functions, it is pretty quiet. It pumps the fluid up (by pcv pipe) about 5 feet to the main waste pipe. It is hard for me to believe that human solid waste can be pumped up like that. What I mean to say is that we are afraid to "crap" (sorry for that) in that commode. Is that really okay to do?

Synder