I've got an older garage (about 25 years old) with a concrete floor. I just keep some cardboard boxes full of junk in the garage. It seems that during rainy periods, water seems to be seeping up from the ground. I'm not saying there are puddles or anything like that, but the boxes have a definite odor of mildew. Can anybody suggest a concrete sealant? I went to HomeDepot.com and found one that is water-based and another that is solvent-based. Thoughts?
OT: concrete sealant
- Thread starter nitanee123
- Start date
That water is going to go somewhere. I'd rather have it sleep into the garage than the house.
I don't have any suggestions for you in terms of actual sealant. But the first thing that I would do is check your gutters/downspouts around the garage structure. I had an undersized gutter on my garage roof with a gutter cap that was NOT catching all of the water into the gutter and instead was spilling down to the ground where it would pool next to the garage wall. Over time this started seeping into the garage and the finish would flake off and the concrete was wet after a good storm.
Also I would check the grade of the yard and the downspouts as well to make sure they are moving water away from the structure. No matter what sealant you may use, if you don't solve a current water issue it will come back to bite you.
Also I would check the grade of the yard and the downspouts as well to make sure they are moving water away from the structure. No matter what sealant you may use, if you don't solve a current water issue it will come back to bite you.
A
anon_1eeb2b426hv3y
Guest
THIS^^^
Water will seep up through concrete. Oftentimes, it just evaporates unless covered. I’d get your stuff off the floor, even a half inch or so, until you solve whatever issue is keeping/allowing that much water by the structure.
Pennsylvania. I was told that concrete guys may have forgotten to put an additive when mixing the concrete. I can see definite chipping around edges. I think somebody did a lousy concrete job.
Go to a good concrete supplier for sealant. You may pay more, but you will get a much better product. Make sure you tell them about the moisture issues. That will probably affect putting down sealant since most call for clean dry cement.
Pallets. Always stack cardboard boxes on pallets.
As someone mentioned, if water is seeping up through the concrete from below, sealing it on top could create a larger issue. I'd figure out why the water is there before attempting to "fix" the problem.
As someone mentioned, if water is seeping up through the concrete from below, sealing it on top could create a larger issue. I'd figure out why the water is there before attempting to "fix" the problem.
There are no additives for this situation for someone to forget. As was mentioned earlier, it's likely condensation and or humidity that is being trapped by the materials you have stored on the floor. Chipping around the edges doesn't sound like it indicative of any particular issue other than normal wear and tear for 25 years of freeze/thaw cycles. There are some things that could have been done during the original pour that compromised the strength of the concrete from day one..... 1) going cheap and using concrete that less than 3000 psi 2) the finishers adding water to the concrete to make it easier to finish, adding water will weaken the surface/edges of the concrete 3) improperly curing the concrete during the first 30 days after the pour.
Pouring it when it's too cold outside probably fits into this bullet point.
For a recent industrial application, the contractor used something called Ultrapel, made by Triangle Coatings, Inc. It's for a new building that will hold municipal vehicles.
As mentioned it has nothing to do with any lack of additives (admixtures). What the contractor likely did forget, or more likely not even bothered, to do was install a vapor barrier below the slab.
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Placing a vapor barrier on a stand alone unconditioned/unfinished garage structure is not considered standard practice. If there are drainage issues then vapor barrier wouldn't help much, if there are no drainage issues a vapor barrier wouldn't be needed.
It may not be standard practice, but the point of the vapor barrier is to control moisture coming up through the slab, so it would certainly help the situation if that were the issue. It doesn't have to be drainage issues it could be a high water table.
I've experienced the same here in Maryland. It can really build up on my filled 5 gal gas containers in my detached garage with temperature swings, but it occasionally happens in my 3 car garage as well with other liquid containers.
I agree that it would help absent drainage issues, I was addressing your comment that someone "forgot" it.
To the OP: Is the water condensation or coming up through the cracks and joints in the slab. Or do you have leaky doors letting rain in?
A dehumidifier would solve your condensation issues. Replacing door seals solves the leaky doors.
If the water is percolating through the cracks and joints you need to give it another outlet. You might be able to dig along side the pad to the gravel base and outlet it there or you may have to cut out part of the floor and install some drains. I am of course assuming topography is working in your favor.
A dehumidifier would solve your condensation issues. Replacing door seals solves the leaky doors.
If the water is percolating through the cracks and joints you need to give it another outlet. You might be able to dig along side the pad to the gravel base and outlet it there or you may have to cut out part of the floor and install some drains. I am of course assuming topography is working in your favor.
Unless there is a product out there you can apply to wet floors, my opinion is you need to take care of your water issues first. Any sealant I have used always required a dry surface.
I yield to all the experts here that know what to do without seeing the garage or knowing anything about it. All I will add is that sealing the floor can make it very slick, especially when wet or with snow on your shoes. Know one guy that had his car slide right through the back wall of the garage. Ask dealer about using something in the sealant to help with that issue.
I can't see a layer of water or even condensation. It just has a mildew odor and cardboard boxes just feel like they are damp (but not wet). Some of the boxes have books and they appear to have an (almost unnoticeable) mildew film/mold. I don't use the garage for anything but storage and I'm reluctant to put anything in there that could be affected by it (like furniture). I was hoping the sealant would help.
I actually think that it may be a bad idea for the situation you're describing. If you seal a slab that is seeing moisture wicking from below, a sealer will just trap the moisture in the slab. This will make more susceptible to freeze thaw damage.
In that case I would suggest a dehumidifier. Or some other ventilation system to get the humidity out.
First thing I'd do is put all the things from the carboard boxes into nice big sealed containers. They're less than $10 at walmart
I have a couple of quick questions; how bad is the floor cracked; number of locations cracked and any idea as to the thickness of the concrete floor?
When I bought my house, well, I had something similar in the cellar. Because of this the bad smell persists not only in it but also in the house, it was unbearable. Then I searched and found a material with a speed of polymerization and development of resistance to bonding on a wide range of surfaces that I was pleased with. All important is that what you will use belongs to that category of remove sealant that is necessary raw materials from which your floor is built, otherwise you risk not being successful in what you proposed to do
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Since someone just responded to this old thread, I went back to reread my posts. While it would not have affected your original moisture issue, I should have mentioned that there is a standard concrete admixture that is used for outdoor concrete like driveways and sidewalks that helps protect from freeze-thaw damage and increase durability over time. It's called an air-entraining admixture, it adds tiny air bubbles throughout the concrete that allows it to better withstand expansion and contraction due to freeze/thaw cycles.
Whether or not it was added to your slab or if a contractor would even think to use it in your situation... who knows?
Now about an update? Did you seal it or do anything else?
Sounds like you have moisture transmitted theough the concrete as you say there is no visible water or even moisture on the surface, just damp boxes from sitting on the floor. It is quite normal for moisture to pass through concrete. Use some duct tape to tape some plastic onto your basement floor. Within a day or two there will be moisture on the side facing the concrete.
All concrete should be poured over a base of stone 4” think to allow separate the concrete from the ground and allow water to stay below the concrete. Often, crews will place a large sheet of plastic, minimum 6 mil thick, and pour over that. Finishers don’t like to do that as it causes the water in the pour rise up instead of sinking into the ground. 5his means they need to use less water to bing with making it harder to,pour. It also means it will take longer for the concrete to set before they can trowel it. But it does help prevent moisture.
As for now.....if that is your problem......a good sealant will help. And it is advisable if you don’t have true water issues. An epoxy finish will also help but is more expensive but also more durable. Either one can lead to slippery floors so consider adding special sand or similar product to prevent slippage. But too much sand will leave such a rough surface it will be hard to clean so do so judiciously.
Or just put plastic down under the boxes.
If that slap is reinforced with rebar, you are going to have serious issues in the future. The water is penetrating the slap and the rebar is slowly rusting. Like others said, the cheapest and easiest is to minimize the soil saturation. Call an concrete professional and see if he has options of increasing the foundation. Sometimes they can “inject” new concrete under the slap to support the original foundation.
I would be really concerned if the original slab is reinforced by rebar.
I would be really concerned if the original slab is reinforced by rebar.
As mentioned by others, moisture comes through concrete so get boxes and other items off the floor. Get all water away from garage, gutters draining away. Slope of area away. Could do tile drains (PVC pipe with holes laid in gravel trenches running away). If just in summer, could be humidity naturally in the air condensing on items as they cool, then sealed garage maintains moisture. To avoid this need air to move by opening windows or blowing exhaust fan. If you live in Philly area you have plenty of heat and humidity.
Very few residential contractors are going to install vapor barrier under slab on grade construction, especially in a detached garage construction. If the grade slopes away from the exterior walls then that should address the majority of moisture issues. Since it's too late for the vapor barrier, I suggest storing your stuff up off of the slab.
I'm sorry but I just saw this reply.
Update: I contacted somebody who does concrete work and he suggested a sealant. I wish I knew the name of the material. I had him apply it, it took about 48 hours to dry and it seem to be holding up. I haven't had any issues.
Ironically, I am now going through the same issue with my basement. I contacted a company that primarily does french drains inside the basement. The estimator was honest enough to tell me that their french drains may not solve the problem of water coming up through the concrete. So I'm going to try to have the basement sealed/cracks filled and hopefully that solves my problems.
Are you still experiencing an odor of mildew? That's my biggest peave right now.
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