Where'd the water come from

I’m stumped. Todays inspection was an older home that had a garage with a basement added on. The garage floor is spancrete with poured concrete over it. A set of stairs goes to the basement area under the garage. There are no water pipes on the lower level under the garage, there was no sign of water leakage from the floor above which is the garage area and the home has been empty for 9 months. The water was pooled in the center of the lower level floor. No signs of where it may have come from. Is it possible for the spancrete to sweat. If the bottom side of the spancrete is cool because its below grade and the upper level in the garage is hot (it was 95 degrees last week) can this be condensation?

Since the water was concentrated into one area of about 5 feet around it just didn’t seem like that could be what caused it.

Are you sure it was water?
I’ve encountered other liquids left by the homeless or vandals.
Just a thought.
You should have been able to trace back to a source if it was a drip.

It was water, although I didn’t taste it. Absolutely no trace of where it came from, it had been there awhile, the floor was painted and beginning to bubble up where the water was.

Sounds like hydrostatic pressure working.

Could be under the slab water pressure. No Basement slab is perfect , that is the cheapest , thinest concrete deal in the building . Be lucky if it is 4 inches…:wink:

Figure on concrete as a porous material and soils as sponges holding all that water.
Now add high dry heat for days (evaporation) and right about now you should see efflorescence everywhere on “real” brick buildings too…:wink:

Based on the quality I saw in the rest of the house a 4 inch slab would be surprising. Sometimes I feel like telling the client to run as fast as they can from this place. Obviously I don’t.

Sounds like you may have answered your own question. The fact that the paint is bubbling up in the area of the water would cause me to suspect the water is migrating up through the slab as mentioned already. Paint will do that when the water is forced or migrates through. The same can be observed on wooden components of a home if it is painted when the wood and trim is still too wet. The water in the interior of the wood migrates to the surface and the paint blisters or begins to peeling or flake off the surface shortly after painting. I see it all the time here in the SE because it stays muggy (humid) most of the summer.

Check RH% & use your non penetrating moisture probe. You might find something you don’t see. Doug

I’m with Doug.This floor paint would not just blister because it has water on top of it.But it will however blister if there was a presence of moisture under it before they paint the floor.

…does it look like anyone cemented over a floor drain?

… your SURE the water did not enter through a part of bsmt wall few days-week ago and settle in a low spot on basement floor before your inspection?

…IF, it didnt come from an Inside source and, didnt come from part of basement wall then, certainly could be a blockage UNDER the floor which often can be freed by getting an honest/experienced plumber to snake through the storm-trap, Not all basements have access to free a blockage under the floor.

have run many estimates over the years where many homeowners who had similar situations `n ONLY needed storm trap snaked, correctly! if anyone does Not believe, then call these homeowners & plumber yourself, ill glady give ya numbers

even if the bsmt floor is thin, a blockage-back up under the floor will allow easy migration/wicking so, snaking when possible imo is first step, cost should be approx $150-$200 tops.