View Full Version : Basement Shower work around?

10-08-2004, 02:19 PM
I am finishing the unfinished basement of my 1930ís house and adding a bathroom. The basement already has a toilet (original to the house). Plumbing for the sink would not be a problem because there is a drain about 15í away serving the kitchen up on the first floor and a wash basin in the basement. This drain exits the basement via the foundation floor. My question relates to the drain for the shower/tub I intend to install. I donít want to jackhammer the foundation simply to install the shower/tub drain and the Saniflo system is a bit pricey (close to $1,000). My question, is there a work-around for this problem? I realize that regardless of the route I take I will have to install the shower/tub on a raised platform (2x6s standing on edge) to accommodate the p-trap. Is it possible to run the shower/tub drain line to the line serving the kitchen? (I could design it to move the shower closer to the kitchen drain line, approx 10í but I canít recall what the grade of the line must be. 1Ē every 3í rings a bell.) Is this a workable solution? I wonder, but seriously doubt, if there is some kind of adapter I could install under the toilet to allow for a branch drain line serving the shower/tub?

Many thanks in advance. Iím not trying to cut $$ corners but this is only going to be an infrequently used guest bedroom so the Saniflo seem a bit much for the use of the room.

10-08-2004, 03:23 PM
You need 1/4" per foot. A shower needs a 2" drain line. Double check those numbers, but I'm pretty sure they are correct.

10-08-2004, 04:59 PM
Jim's correct and there's more. There is not a fitting for under the toilet without breaking concrete. You can tie your shower drain into the kitchen sink drain above the floor but you need a vent.
Basement bath projects require a vent to the outside. This is usually achieved by running a pipe up through the upper floor about 42" and tieing into a vent pipe servicing that floor's fixtures. If you only have the kitchen drain pipe for a vent then you are already wet venting a lot.
Breaking concrete is not that major. Building and maintaining an above floor box-in does not necessarily mean you are saving money. Concrete is cheaper than wood but more work of course. You're not going to want to allow infrequent use if you're never sure when it's going to overflow on the users.
Watch the toilet after you flush it. Sometimes water comes up in the shower drain.

10-10-2004, 06:48 PM
LonnythePlumber and Jim:

Thanks for the info. Jim, it's good to know that even if I relied on memory (which I never do in these situations) I would have overbuilt by allowing an inch for three feet when code only would require 3/4" for 3' feet of grade. LonnythePlumber, your response is what I was afraid of. There is a vent stack serving a wash basin in the basement I can probably tie into. I just never noticed it as it was hidden by a small closet. With regard to breaking the concrete, I feel pretty confident in my framing ability (just completed a two-story addition (no plumbing)) and my preference is to stay away from cutting concrete; too much potential for problems.

Two questions. First, you mentioned "You're not going to want to allow infrequent use if you're never sure when it's going to overflow on the users." Are you talking about the shower? In retrospect, I will probably use the shower at least once a week as a "mud room" shower when working in the yard. Second, you also mentioned, "Watch the toilet after you flush it. Sometimes water comes up in the shower drain." It seems if I use the kitchen'wash-basin drain and vent, I should not have to worry about water coming up in the shower if the drain is properly graded. Am I wrong?

Thanks again for the help.

10-10-2004, 08:51 PM
I was making overstatements to support the need for a vent. You have found a vent and should have no problems with use.

10-12-2004, 10:56 AM

No problem. I just wanted to be certain that I wasn't missing something. I know enough to do it myself (including the need for venting) on the simple things but realize I can easily get into trouble if I miss something that is normally standard practice but is such a standard that it's seldom menioned on forums. Thanks again for your help. After I finish the basement bathroom maybe I can spend time inventing a pedestal of sorts that allows one to use the toilet drain for later-built showers in basements where the toilet is built in but no drain stubbing for showers/tubs. There are a lot of those in my area.

Thanks again.