Hey everyone. I have a question but I don't have many details so I'm
only looking for a general idea as to what this project is going to be
like. I am considering adding a second bathroom to an investment
property of mine. It's on a slab built in 1964. I'm wondering about the
plumbing part of this project. Is it difficult (expensive) to add a
bathroom on a house with a slab as opposed to a crawl. I'm going to use
existing floor space(utility room). Also, I will hire a plumber, I'm
just wanting some general information about this. Does the slab have to
be disturbed, or can the existing plumbing be "tapped" into? Any help
would be greatly appreciated.
The pipes have to go somewhere. Supply pipes can go in the walls but DWV
pipes need to be below the fixtures they are draining. You might be able to
elevate the tub/shower and toilet so the pipes run in a wall cavity (on top
of the slab) until you can dive into the drain in the slab but that takes a
lot of headroom away from the bathroom. It dosen't sound like you have high
An alternative would be to use a sump pumped setup where the waste water is
pumped overhead then discharged into an existing drain. This might cost as
much as tearing up the slab and has similar headroom problems.
Another alternative is to install the waste pipe on the outside of the
building but you still need the toilet and tub drain to be above it.
Best to plan on wrecking part of the slab if you want a seamless
The plumber will charge significant labor for this, you might be able to sub
that part of the job to someone cheaper or do some of it yourself.
We did something similar in a major remodel two years ago. Added a
master bath and a laundry room at opposite ends of the house.
Needless to say, the plumbing was a bit of a challenge. The bathroom
was close enough to the existing wet wall (all previously existing
plumbing fixtures adjoined this wall) that we just had to tie in to the
existing plumbing. Of course, we needed new drains and vents, and for
that the contractors punched through the slab where necessary and tied
into the old ones.
The laundry room was a different situation, for which we had to add a
new water heater (our house now has two) and new sewer line.
Contractors were able to install these things as the new slab was
It sounds as if your addition will be similar to our new bathroom. Yes,
the plumber will need to punch through the existing slab to add drains,
vents, and tie into the sewer. They just jackhammer a hole big enough
to put whatever is needed underground, then fill it back up again with
redi-crete. If your water lines are under the slab, they may need to
punch through to get to them, too. But if they are in the attic or
ceiling joist space, the job will be easier and less expensive.
Call a plumber. Get an estimate. That part is free, but scary.
Here\'s some of my work:
Plumbers around here almost never give free estimates. The repipe guys do
but the repair quotes all cost a nominal fee which is recovered if you
accept the job. Thats not to say; some might in your area.
If the utility room already has a drain and vent for another plumbing
device, the project is simple, but will still require a saw cut and
break out of the slab. If you do not have a drain and vent in the
utility room, the project may get more complicated in the process of
installing same. Your plumber can size up the situation in a flash.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.