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removal of trapped water

I have had a thorough inspection by a well-qualified plumber who found no leaks in my water lines, nor any evidence of any drain leaks. However, according to him, my property experienced a water surge........the townhouse (no water problems with the neighbor) is built on a slab with the water main in the crawl space under the stairwell. His theory is that the PVC sleeve around the copper water main has failed somewhere between the house and the water main valve in the yard. When we experienced torrential rains, enough ground water pressure built up to cause a surge thru this sleeve and into the house. He said the "quick" fix is to seal the area around the copper pipe coming thru the slab with hydrostatic cement. If this fails, then the entire length of the water line would have to be dug up to find the problem.

In the meantime, there is considerable water trapped between the slab and the hardwood floors, and it is slowly rotting the wood and seeping thru the seams. If I get a high-power wet vac, do you think I can remove the majority of this water, or is tearing up the entire floor the only solution?

Re: removal of trapped water

A few questions;

Is the PVC sleeve required in your fair city? Is a movement joint required between the pipe and the sleeve? (I'm thinking earthquakes or the ultra dry soils in desert conditions)

Foam will also seal the pipe to the PVC sleeve and a lot easier. If a movement joint is necessary, 100% butyl rubber would be my next choice.

The hardwoods are a goner. I can't think of any way to get all the moisture out and prevent mold. Got flood insurance?

Re: removal of trapped water

Both the plumber and Houston are correct, IF the water comes through the PVC sleeve.

But what if your main copper has a hole in it, even a pin hole, or has a damaged coupling/adaptor somewhere between the yard and the place under the stairs? In this case the quick fix will not work, and a new main pipe bypass will be needed.
Expensive, ouch.
I would expose the length fron the yard main valve to the house and look for a leak. If there is none, there could be a leak under the slab.

As far as the floor: rip it off as quickly as you can and dry the area. Then treat the area against mold.

Good luck.

Re: removal of trapped water


I think you should approach this as a 2-stage process/solution.

The first step is to get the water out from under the hardwood floors to prevent further damage; the second step is to get one or two additional estimates from other plumbers as to the best probable diagnosis and solution so the problem doesn't occur again.

The first step can be done as a diy project if you want to go to HD/Lowe's & buy a heavy duty pump with perhaps a 3/4" or 1" garden hose connections (or a sump pump-see below) to the pump intake & output connectors so that you can pump out the water to minimize the damage; the input hose can be no more than 6 feet with a 1" hole drilled in the crawlspace, or other out-of-the-way location so you can access the standing water still sitting on the slab; the output hose would have to reach out of the house & out to a spot in the yard where gravity will take the expelled water away from your house & property.

Pumps are rated & sold according to gallons per minute (gpm) they can process--if you do this, buy a pump that can pump out 30 to 50 gpm so you won't have to wait all day & all nite to get the water out.

The second phase of the solution is to hire a contractor to fix the cause of the leak, once the actual cause has been reasonably established.

It is quite common with spring rains to have water buildup under a slab or under & around a basement wall that results in basement or slab flooding---although it seems at the time like a major disaster, the water always goes down eventually, and steps can be taken to insure that it won't happen again.

If you have access to the slab/water from the crawlspace, it's a good idea to have a sump pump installed, which may be a better solution to this than buying a high capacity pump; the sump pump can be permanently installed & will come on automatically if this situation should happen again---the main problem MIGHT be that there is a crack or two somewhere in the slab that is letting water into the house during bad rainstorms.

Another long-term solution may be to install a concrete "catch basin" containing a sump pump right into the slab about the size of a trash barrel---this would act as a low point to catch any water that gets under the slab during a rain storm--again, the sump pump would come on automatically to effectively pump the water out of the basin (since it would be the low point) & prevent any damage to the house.

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