Toilet to ejector pit vent question

[Schnabeltasse]

Hi, I’m new here - hope this is the right place for this question.

I’m about to pour the slab in a basement that will likely never get finished but will have some shop space and storage. I wasn’t going to put a bathroom in there so wasn’t planning on underslab plumbing but as a last minute thought I’m wondering if I should at least put some provisions in for a toilet. I already have an ejector pit in the ground that was intended for a future sink in the shop area (plumbing entering the pit above slab through the lid). If I wanted to add a toilet, what would I need? I was thinking put a short 3” pipe from the pit a few feet over and box it in to keep concrete away from the pipe so I can later access it and put whatever fitting on it I might need at the time I install the toilet or is there such a thing as a standard toilet fitting I can install now? Do i need a vent if the toilet is only a few feet from the pit? My engineering mind tells me no since the pit will have a 2” vent and the toilet will drain to the pit above water level so should be able to pull air through the pit vent but maybe I’m missing something? How far away could the toilet be in that case? If I wanted to add a shower drain (or floor drain etc) should I run it separately to the pit or can it be tied into the toilet drain? Would it need its own vent?
Thanks!
Schnabel

 

[Reach4]

I was thinking put a short 3” pipe from the pit a few feet over and box it in to keep concrete away from the pipe so I can later access it and put whatever fitting on it I might need at the time I install the toilet or is there such a thing as a standard toilet fitting I can install now?

A capped vertical 3 inch pipe would be a good provision for a closet flange. Ideally when you pour the concrete, you leave a space around the pipe for an outside flange. The better fitting would be a 4x3 closet flange with a "spigot" port (same size as 4 inch pipe) sticking up. I am not a plumber. I don't know how to best plug that until you install the toilet. There are glue-on flanges that have a knock-out meant for holding pressure for pressure testing. You could install a glue-on flange with a stainless steel ring, and leave the knockout in place. I am not a plumber.

Do i need a vent if the toilet is only a few feet from the pit? My engineering mind tells me no since the pit will have a 2” vent and the toilet will drain to the pit above water level so should be able to pull air through the pit vent but maybe I’m missing something?

I agree that having a separate vent seems quite unnecessary, but I don't know the rules. They can require stuff that seems illogical. A toilet does not need to be able to pull air from a vent. A toilet is unlike other things in that its trap is supposed to siphon, and then the trap gets refilled as the tank refills. It will be interesting to read what the code require. I think Florida code is based on IPC, which tends to be more permissive than NPC.

A toilet need air to be able to go the other way. Your pit will have a real 2-inch roof vent, so that would let air pushed by a toilet flush escape.

 

[Sponsor]

 

[OLD TIMER]

Your first step is to sketch a floor plan with dimensions. Then someone can help you.

 

[Schnabeltasse]

Your first step is to sketch a floor plan with dimensions. Then someone can help you.

Here is a sketch. Thanks!

 

[Cacher_Chick]

The most logical layout would have the WC vented through the lav, and the shower would require it's own vent.