Best method / coating / covering to seal concrete garage floor

Hydrostatic pressure is probably the bug-a-boo here.

We had the same problem in one of my rental offices. They installed a tile floor with a water based adhesive and it NEVER DRIED. Adhesive seeped out between the tiles, it was a GIANT mess.

We stripped the floors and used an epoxy coating that was designed specifically for this problem. Unfortunately, it was 20 years ago and I can't recall the name of the product.

It worked, even though it was applied over a surface that was not quite damp, but certainly not completely dry either. 20 yrs later, it's still working like a charm.

I suspect someone here will know what to apply, just be sure to explain carefully to whomever you buy the material from that you have a wicking problem, and that the material needs to stay stuck.

DM

 

I'd love to, but the force is no longer with me, I am, sadly, a moderator emeritus now.

I'll hit the !, see if we can get 'er moved.

DM

 

What works best is laying down plastic before the floor is poured. I have a similar problem at my old house and I put slate down on the floor which pretty much stopped the problem as the slate would soak up all the water before it wicked through. I also sealed the slate several times. If you paint/epoxy floor my guess is it will peel in short order.

 

Probably not much you can do to get the moisture from seeping up. I guess you could seal it, but you'd just be trapping in where it doesnt want to be. Busting up the slab would be the best fix I think. Either that or maybe put a membrane down, and repour a topping slab?

 

When do you notice the moisture?

If the surface is at grade there probably isn't real hydrostatic pressure like you'd get in a basement.

There are concrete sealers that moisture-cure and need to be applied to a damp surface.

 

the purpose sealers is to keep water going into the slab from the top, not to keep water from coming up from the bottom.

 

Have you considered a sump pump?

 

try xypex concentrate

 

Probably not much you can do to moisture indoors. I think we can concentrate, but you just want to catch, if you do not want to be. Exposing the plate would be the best remedy in my opinion. Either that or maybe put the movie down, and repour topping slab?

 

I used a Rust-Oleum Epoxyshield. Its a two part epoxy paint made for garages. Worked great to seal the floor. You have to wait for dry weather and make sure the slab is dry before you apply it... but after it cured it resists water from above and below.

 

Hi David,
You may want to try trenching around the slab on the outside and using a sump pump or just gravity (if possible) to evacuate the water. If in a cold area, put the field tubing, pump outlet tubing and sump pit, lower than the frost depth. Of course I don't know if there is a suitable place (lower elevation) for open dumping of the discharge, if you'll have to use a "dry well" or a drain field, to "relocate" the water. Just a thought. That much water could cause serious problems with the slab, especially in a cold area.

Good luck,
Bill

 

this is from personal experience.

1. do a french drain completely around the shop/barn, make sure the rain gutters feed into it and it drains well away from the slab.

2. zypex over the slab keeping it moist so the crystals can fill in all small holes in the concrete, then use a cementous product like westcoat, this can be made to look like tiles. expensive and time consuming but took care of the problem when epoxy, vct tiles failed. I will post a picture when I get to it.

 

The French drain is a great idea. Trench around the whole building with an outlet at the lowest point leading to a cistern. Fill the trench and cistern with rocks and cover with newspaper (start saving) or cloth and then cover with dirt.

If your outbuilding is metal, you may have an overgrown solar still that is condensing water overnight that flows down to your concrete floor. Some vents high up in the sides and possibly an exhaust fan in the ceiling would help cut down on the condensation. If you look at metal buildings in high humidity areas, the bottom of the wall near the slab will tend to rust out first because this is where the condensate concentrates.

Taz
Terry Phillips