Condensation issue

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Doesn’t seem reasonable that enough water could migrate through 4-6 inches of concrete to form puddles of water in a short period of time. The permeability of mature concrete is about .1 billionths of a centimeter per second. I’m not an expert on this by any means but I think it means that it would take 10 billion seconds for some amount of water to travel one centimeter in concrete.
 
Doesn’t seem reasonable that enough water could migrate through 4-6 inches of concrete to form puddles of water in a short period of time. The permeability of mature concrete is about .1 billionths of a centimeter per second. I’m not an expert on this by any means but I think it means that it would take 10 billion seconds for some amount of water to travel one centimeter in concrete.
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I thought he meant that the water was coming in under the wall.

Post 22
 
I forgot to mention this earlier, but I also got a lot of improvement in the sweat situation when I put in a french drain all the way around the outside walls. It was very cheap and helped a bunch.
 
I don't know where ALL of it is coming from. I know some is coming under the walls both in the rear and on the side closest to the house. I also know it sweats even when it does not rain. It seems to be simple condensation and not pressurized water from underneath, as it only does it on days with really high humidity......which has been a LOT this year.

And of course "I" am no expert either, but I am just saying what I "see".
 
I don't know where ALL of it is coming from. I know some is coming under the walls both in the rear and on the side closest to the house. I also know it sweats even when it does not rain. It seems to be simple condensation and not pressurized water from underneath, as it only does it on days with really high humidity......which has been a LOT this year.

And of course "I" am no expert either, but I am just saying what I "see".

My garage used to sweat like crazy. I painted the floor , which was very porous and rough , "DONE BY AMATEURS BEFORE I BOUGHT IT" .
It almost completely solved the problem. Musta been coming up thru the concrete for the most part. A drastic temp. change w/ hi humidity
will still get a little, but not like it used to.
Sounds like u need a French drain----------- if u install one u should water proof the foundation as best as possible while doing it too.
 
It’s most likely condensation. When the surface temperature is lower than the dew point, water vapor in the air will condense on the surface. Therefore this will happen on high humidity days when the slab temperature is cooler than the dew point. This is tough to fix without lowering the humidity in the space or raising the temperature of the slab or air. Moving air over the slab will help by causing the condensation to evaporate.
This is most likely your issue RRR. I opened the garage door garage a few weeks ago after a cold snap to let some warm air in but it was humid. Instant condensation on everything.... including all over a new crank being fitted in a block. Heating the space or the slab is what is needed. Sealing won't change this particular matter and if you seal a slab that does not have an adequate vapor barrier under it, you are just locking moisture in the slab.

If moisture is coming up through the slab, you may also have poorer drainage on one side that may cause that side have more moisture under it than the other. Hard to fix if you are on flat ground; one more reason I don't live in the flat midwest anymore; it's hard to get good drainage in the flatlands there, and a lot of effort needs to be paid out there to prevent these issues.
 
Yeah it happens on my porches and in my shop. Where the air is not conditioned. It's pretty common where we have 40 degree swings in temperature in just a couple days. Slab cools down to ambient, when the temperature goes back up to 80, bingo. Sweating floor. I've been told the only thing you can do is keep the slab warm. Few different ways you can do that, heater mats poured in epoxy or hot water run through tubes. None are cheap.
 
I know exactly what's causing it
We have temperature swings here.
Moist saturated air warmer than his concrete .
It's worse if the car is lower than higher.
But it sure seems that if more of that air gets to the surface it just condenses more.
Sort of counter intuitive.
Best thing I've found is seal the building from the air changes.
 
^^High humidity in the air I bet^^ I bet what will fix it is insulating the building and making the building tighter

Concrete is really not all that porous. Hell they make BOATS out of the stuff. Here we have the annoying-expensive-overblown-world-class "floating green" and yeah, it floats, and it's concrete...........basically the damn thing is a gigantic concrete barge

floating-green-coeur-dalene-golf-course-10.jpg


Down inside the thing at 3:10



And no, I don't golf and I would not go there if I did!!
 
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