How to Install a Basement Toilet

LESLIE: Well, today, more and more extended families are coming together under one roof, whether it’s for an economic reason or a health issue. And if that’s the case in your house, you might find yourself looking for more space or even an extra bathroom.

TOM: And one of the best places to expand is actually down under. And no, we’re not talking about moving to Australia; we’re talking about your basement.

Basements make really terrific living areas if they’re properly finished and that includes installing a below-grade bathroom. To find out how to do just that, we turn to a guy who knows exactly how to make a plumbing system defy gravity: our friend, Richard Trethewey, from TV’s This Old House.

Hi, Richard.

RICHARD: Hey, guys.

TOM: And most people think that putting in a bathroom below-grade requires a lot of work and expense but that’s not necessarily always true, correct?

RICHARD: Well, it always was, you know? You had – because you didn’t have gravity to work with, you always had to open up the basement floor and put a thing called a sewage ejector: this big pit, like a sump pit, that everything came into. And that was pretty extensive.

And then we saw this product some years ago that allows you to actually put a basement bathroom in without having to dig up the floor and it’s pretty, pretty ingenious.

TOM: OK. And what’s that called?

RICHARD: Well, it’s a product called Saniflo and it has a variety of iterations. One is just a straightforward unit that’s a toilet that sits on the floor and it has a macerator in it so that it’ll grind up and pump out the waste through a relatively small pipe – a little ¾ pipe – and that will go into the OP and then into the drain system.

And then they also have one that can allow you to have a tub or shower drain off the side of it and also allows you to bring a lavatory, so that it – but it makes most of its work be done above the finish or above the basement grade of the floor.

LESLIE: Now, is there any limitation to – as far as the distance you might need to actually move the waste to get into the main sewage? Like can you only keep it under a certain distance?

RICHARD: No. There’s no practical limit in residential. I mean you could – I don’t think there’s a house that we couldn’t get this thing to pump it out.

TOM: Now, because it’s sitting on the floor, do you have to build a throne to put your throne there?

RICHARD: Well, no. It comes off the back. It’s designed that way, so you do see this little, white tank off the back of the toilet.

TOM: OK.

RICHARD: And then it has a place – you may have to build up your shower height. So if you have a really low basement, if you’re trying to do a shower stall it might get you into a little bit of trouble.

TOM: So the toilet is different than – the toilet doesn’t drain below it. It drains out the back?

RICHARD: No, it’s expressly made for this device and it’s a matched unit, so it’s not – you’re not putting a conventional toilet there.

TOM: Oh, OK.

RICHARD: But it’s an ingenious – it’s really ingenious because there are so many people that just would love to have a basement bathroom and historically, it was just prohibitive to get this thing done.

LESLIE: Mm-hmm. Well, I know. In so many communities, there are a lot of limitations to what you can do as far as a bathroom in a basement area. So really, I think the first step is going to your town’s building department and find out what the rules are.

RICHARD: Yep.

LESLIE: Because since I’ve started working as a decorator, I can’t tell you how many families who’ve just bought a house and there’s a bathroom in the basement. And they’re going to go do some decorative work and they go to file the permits and the town’s like, “Whoa. That bathroom’s not legal. You’ve got to get rid of it.”

RICHARD: I always prefer to be up-front with the local establishment and sort of – when I had to do a – build a house, I went right to the town hall and said, “Tell me how to do it the right way.” And it’s amazing how they become – they go from potentially your adversary to your advocate.

TOM: Good advice. Richard Trethewey from TV’s This Old House, thanks so much for stopping by The Money Pit.

And to see a great video of how to install a basement toilet, including that Saniflo system that Richard mentioned, you can visit ThisOldHouse.com.

LESLIE: And remember, you can watch Richard and the entire This Old House team on This Old House and Ask This Old House on your local PBS station.

TOM: And This Old House is brought to you by Lumber Liquidators. Lumber Liquidators, hardwood floors for less.