Hello,

We are planning on finishing the basement of our 1942 house in Seattle. Currently, it has an unfinished cement floor, foundation walls, and exposed ceiling. We're planning on staining the floors, framing the exterior walls and adding a few interior walls, and drywalling the ceiling.
There is a washing machine draining into a pipe that is connected to the main sewer stack, and the hot water heater drips out onto the floor, which has a drain 1 foot in from the stack.
We'd like to put in a bathroom with toilet, sink, and shower, with the water heater in a closet along the same "wet wall", and would like to do whatever we can ourselves, though we know we'll be hiring help for the major work. We also want to put in a laundry/kitchenette sink directly next to the sewer stack. The only vent is on the main floor in a wall that would be hard to get to.

Questions:
1. Can we do this project at all without cutting into the cement floor? We've looked into Sani-flo and some other "macerating" toilets, but read some negative reviews and with a shower going in also, we're not sure about the Sani-flo tie-in being appropriate for our sewer set-up, since it seems to be below the cement floor.
2. What about wall-hung toilets and a raised shower floor, can they be connected to the sewer line within 15 feet?
3. What's the best way to vent all of these fixtures (2 sinks, 1 toilet, 1 shower, and 1 washing machine)?
4. What's the best way to handle draining a water heater (and does it need to be vented)?
5. What are the pros and cons to having a floor drain?

Any advice is much appreciated... we'll get pics up in the next day or two, in case that's helpful.

Thanks! :)

Seattle huh? Growler out of be all over this one when he sees it.

1. Can we do this project at all without cutting into the cement floor? We've looked into Sani-flo and some other "macerating" toilets, but read some negative reviews and with a shower going in also, we're not sure about the Sani-flo tie-in being appropriate for our sewer set-up, since it seems to be below the cement floor.

I guess you could platform the basement floor, if you have the head room, and install the drainage under the platform and, yes a Sani-Flo isn't appropriate for your installation, but wqhy not do it the right way and put itv under the cement.

2. What about wall-hung toilets and a raised shower floor, can they be connected to the sewer line within 15 feet?

Sure they can but you're still thinking platform floor and do you have a wall that will accept a wall hung carrier?

3. What's the best way to vent all of these fixtures (2 sinks, 1 toilet, 1 shower, and 1 washing machine)?

Every fixture that has a trap MUST be vented. A circuit vent would be used on your fixtures. This would tie all your fixtures back to a vent stack with the exception of the shower which would be wet vented off a vented drain line.

4. What's the best way to handle draining a water heater (and does it need to be vented)?

If you're asking about the T & P valve we pipe it outside for the T & P valve and a heater pan if one's installed. It does not need to be vented.

5. What are the pros and cons to having a floor drain?

Mostly pros. You don't have to vent it, it carries away any spills and you can exhaust the heater' pan drain and T & P valve intgo it by a indirect waste.
The bad part is that as the lowest fixture in the house it will be the first to back up if you have a blockage in the sewer.

Hope this answers your questions, Tom

It will be nearly impossible to do a good job without busting up some concrete. You need to tie into your drains and it sounds like that is under the slab 15 feet away. If you put your gas water heater in a closet you need to insure adequate air supply for the flame, not important if it's electric. Another consideration would be moisture. I've heard Seattle is a bit damp from time to time so a moisture barrier on the walls will be important as well as a floor sealer. Do you have any seepage and is there a sump pump in the basement? Floor drains are usually not connected to the city sewer line but in 1942 who knows how it was built. Back to you.

I'm not a big fan of the macerating toilets, but you're right, adding a shower into the mix makes it a moot point.

Wall hung toilets are expensive, as are the required in-wall carriers.

You are going to need at the minimum, a 2" vent run up either by itself, or tied into an existing vent that is large enough to accommodate the additional fixture units.

If you break up the floor, which seems likely, you are probably going to lose the existing floor drain, which means you'll either have to gravity drain the H/W tank T&P to the outside, which probably isn't doable if the basement is below grade, or you are going to have to provide another floor drain or indirect drain, and you will also have to provide a trap primer for either the floor drain or indirect drain.

This being a basement installation, you're probably below the manhole cover out in the street, which means you will need to protect all of the drains in the basement with a backwater valve. If this is the case, then backup's through the floor drain from a plugged sewer line aren't going to be much of an issue -- Unless one of the fixtures in the new bathroom or laundry plug up the line before the backwater valve.

If it were me, I would opt for an indirect drain with it's overflow height set about eight inches above the flood rim of the water closet.

Not a code requirement -- Just a personal preference of mine.

Pics are always helpful.