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How to install a basement bathroom

You can never have enough… bathrooms. At least, that’s what some families discover. If all that’s left is the basement, here are some things to look for while planning the new loo-cation.

If you’re lucky enough to have the main sewage drain below the level of the basement floor — which is the norm in most new construction — you’re laughing. In fact, there may already be a roughed-in drain for a toilet. But if your house is older, the sewage may exit your house at a higher point, anywhere from a foot off the floor to halfway up the basement wall. (Look for that big ABS or cast iron pipe.)

Since, ahem, waste flows downhill, you’re not going to have much luck putting your toilet at floor level, unless you consider these options first.

Upflushing toilets are one solution. These devices work by macerating, or grinding, the waste before using an electric pump to pump it to a higher location than the sewage exit. They look like ordinary toilets, with the slight added bulk of the macerator sitting near the floor. The waste pipes can be hidden from here on behind walls, and in fact, since the waste has been ground up, you can use a smaller-than-ordinary drain pipe. (The unit needs to be vented, as would an ordinary toilet.)

A better method, though one that involves more work to install, is a sewage ejector, which is kind of like a sump pump for your toilet. With this method, you need to cut through the slab floor of the basement and dig a sump pit. The unit sits in the pit, and the toilet sits on top of it, at normal floor level. The sewage ejector can also handle the drainage from your sink and shower.