Slab floors and plumbing?

Question

I'm looking at a house that needs a lot of work, it's older and has a slab floor. I haven't seen the inside yet but I already know it's a mess and the old plumbing will probably have to be replaced. How does one deal with plumbing in a slab? I imagine it's in the slab itself.

Does this always involve a jackhammer? What are the potential costs of having someone else do that? 2 baths & kit. And it is possible or even remotely advisable to instead lay new plumbing and build a floor above it? If so, wooden or cement?

Lynn Harrison · Answer

Thanks, running outside might be an idea. I'll have to see if it is permissible in that county.

K. Marie, it is a late 40's or 50's house I believe.

Another major issue came up today and I think the place might be much more trouble than it's worth in the future, even if it's sold at less than land value. There are underground gasoline tanks  :X  !! It was a store at one point in the past. I will call environmental and ask, but it looks like it could be a huge liability. But, hearing all this is very useful as most of the places I'm looking at are in rough shape. Now I have a better idea on ways to deal with a slab. Thank you all!

Rhett Tullis · Answer

if you mean supply lines for plumbing we will run it overhead when there is an issue under the slab.  if you are talking sewer lines there are ways to locate and repair just the bad spot or run a new line around the outside of the house to the spot you need.  (generally there is an outside wall on most bathrooms.)  there is always a way to do it simpler.

Account Closed · Answer

Lots of doom and gloom here.  We don't have all the facts that matter.  What year was the house built?  Are all the repairs supply line related? Are any waste line related? What is the location of the kitchen, bath and laundry?  Depending on the layout you may be able to abandon the supply lines under the slab and go around the perimeter with new lines.

Lynn Harrison · Answer

Darn, can't edit posts. I think it's likely the heating is non-existing or crap. I'd be putting in a couple of empire propane heaters. It's a mild climate.

Lynn Harrison · Answer

Oh, and Dennis, do you remember the name of the cement you used? Or the type name?

Lynn Harrison · Answer

Thanks guys!

Dennis, why would it not be feasible in a small house? Is it truck delivery? The one I'm looking at is 1500 sq ft- so not small, but I'm curious. And, that might work except that I may have to lay sewer pipe as well- unless the existing bathroom is up against the back and plumbed to the outside- which is common here in older houses. I'll have to measure the wall height.

&, uhm... do you think that might be to code in California if the ceiling height is alright?

This place will not be worth it unless it is cheap cheap cheap. It's a complete or near complete rebuild. I have to see if the studs are solid.

Dennis Jayy · Answer

I did  that once to a big house built on slab with all heating in the floor. Layed new piping and poured a new 1in, cement floor. I used the type that is self leveling, fireproof and sound proofing . It is used a lot for second flooring to stop noise and ect and works great.  I suspect it is not feasible in a small house. Doors are not to much of a problem to raise them.

Also did one where I cut the cement floor and dug down and put  new ducking in the floor and new heating system in a closet. Worked great, but again a large house.

I would really look at putting in a new system , above ground. You can usually find a route to put in duct work or perhaps build runs on ceiling or walls that look nice and hide the ducts. Ducts can also be put outside, in attic and ect. You can even put them in the walls in the existing wall system.

Chances are the old pipes in the flooring are copper or steel and the chemicals in the cement  use to work on corroding the pipes over time.  Most of the old systems  put the pipes in direct contact with the cement.

There is also the possibility of installing electric in wall heaters with fans and thermostat. Not the most efficient but with a good insulated house and windows,  not to bad.

Christopher B. · Answer

unless you've got tall ceilings laying a new floor isn't going to be an option . Even then you're going to face other issues. Dealing with plumbing in slabs is a mess, just make sure your budget accounts for the extra work involved for demo and then repouring the concrete.

Matthew Paul · Answer

Jack hammer is the tool . .   Build a floor above it ?     How are you going to raise all the door ways