Laundry/bath on slab - drainage

**dwhiteykc** · 03-28-2011, 01:23 PM

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Looking for some DIY advice. Purchased a home that has the laundry in a bathroom with shower stall, toilet, sink and hot water heater...and no floor drain. Cutting a drain into the floor and joining to the toilet waste line may be an option, but I'm guessing there would be several lines we'd have to work around (and no idea how the floor was poured, material to excavate, etc..).

Was thinking it may be easier to at least use pans on the wash and water heater and run those drains to the existing ones for the washer and sink? Potential problems with that approach are; the pan drains are so low I wouldn't have much of a drop, and the part of the drain vertical (ABS) I'd have to cut into would be nearly flush to the floor. I've also heard there are potential issues mixing Sch 40 with ABS. I should have started this thread with the fact that I'm an amateur plumber at best! One idea was to build a low 'box' under the appliances - but I'm not confident how the front-loader would respond to a less-stable footing (and if it would walk across the floor with the pan in place, even on concrete).

I know the pan solution wouldn't do me any good in the instance of a blown line or toilet/sink failure -but it would at least give the water from the two most likely flood suspects somewhere to go.

I'm as bad of an artist as I am a plumber...but the black pipes are the existing drains, the one near the sink is ABS and the one near the dryer they cut most of the ABS back to near the floor and is I believe sch 40 with a Studor vent. The other factor that'll challenge me, is that the copper supply lines run all around the room counter-clockwise from the main (behind the water heater). The heater is a Kenmore Economizer 6 and wash is a Whirlpool Duet - haven't researched the pans enough to know if they even make what I need. I'm being 'motivated' by the Mrs. as she's getting flooring put down in there and I've been told once it is in, I'm not chopping it up!

**Pipewrench** · 03-28-2011, 06:10 PM

If your water heater is on a outside wall your best bet is to run a pan drain through that wall to the outside of the house. Nothing else needs a pan or a floor drain. Most bath and washrooms in my parts rarely have floor drains in them. Maybe have your W/M drain routinely snaked out for peace of mind. That is gonna be your only other real threat other than just freak accidents. But your floor drain idea isn't out of the question. Just some jackhammering involved. But tying a pan drain into the vent stack just isn't very practical. You would have to raise up the appliances and cut in a sanitary tee and install a p-trap for the drain to dump into.

hj · 03-28-2011, 06:16 PM

"safety pans" should NEVER be connected to the drain system. They should be run through a wall to the outside of the building.

**Pipewrench** · 03-28-2011, 06:53 PM

Hj is exactly right! When I said that about running the drain line to a p-trap tied into the vent stack I guess I was thinking of a/c condensating drains. Brain fart. Haha! You want it run to a safe and noticeable location outside so you know when you have a problem...

hj · 03-29-2011, 05:34 AM

It is also a bad idea for condensate drains, because in the winter, or during arid periods, there will not be any condensate to keep the trap full, so the AC will suck the sewer gas into the unit and distribute it all through the house.

**jimbo** · 03-29-2011, 06:03 AM

One approach is to try to minimize the likelihood of any damage....get the best hoses for washing machine...Floodchek, Fluidmaster SS, etc. Put in leak alarms or sensors with electric shut off valves.

**Pipewrench** · 03-29-2011, 11:56 AM

Hj that may be true. But where im from the a/c is run from march til at least oct. Ive never seen a trap dry up. We have to worry about algie growing in the lines from the cold water and stopping up. seen lots of damage from a stopped up a/c drain. I try to recommend to all my customers a cup of bleach be poured down it at least once a year.

**Terry** · 03-29-2011, 03:59 PM

Trap primers.
Anytimes you have a trap in a home that doesn't get constant use, it needs a primer to keep water in it. Longer then a month and it can dry up.

**Pipewrench** · 03-29-2011, 07:14 PM

Yes sir. All the floor drains in the buildings around here have primers. Most all of the a/c and heating units are in the attic and the trap comes off of a vent in the attic. I've never seen a trap primer on those.

**Terry** · 03-29-2011, 07:29 PM

Attics are ventilated, I don't think anyone would notice.

**dwhiteykc** · 04-03-2011, 07:02 PM

Thanks for the advice folks - I've got quality 'burst resistant' hoses and quarter turn shutoffs boxed on the washer. Once I convince my wife to use them I should be set! Shortly after buying the home the water heater failed & flooded a good-sized area (luckily was home for it), which is why a drain was on my mind. Its on an interior wall, so can't run a pan & drain outside. I'm half glad the pans are a no-go bc I didn't think the front loader would do well on a platform, skidding around with a PVC pan anyway!

Great forum, will definitely be back. Thanks again for sharing some professional knowledge with a chronic DIY guy.