Skip to comments.Moisture Sealing An Unfinished Concrete Floor - Advice Please!
Posted on 02/27/2014 5:11:03 AM PST by newb2012
Looking to moisture seal my unfinished basements concrete floor as a measure to cure and prevent mold in the house. Appreciate any suggestions, sources and references - about what kind of sealant to use etc.
If unfinished, find a downstairs roughed-in plumbing pipe for a sink, toilet, floor drain, etc. and then wire an outlet near that. Buy tubing, adapters, etc. and connect to a good capacity dehumidifier and keep it running. One with an adjustable humidistat is nice.
I did that in my basement and it is always below 50% in the summer and 30% or so in the winter....it will work for mold, and rust (I keep my guns there).
There is a product called “Anti-spalling compound” It contains linseed oil and a drying agent. I have used it on exterior walks and been very happy with it.
http://www.garagejournal.com/ Go into the forum, entire section on preparing and sealing concrete floors.
Was a vapor barrier put down before the concrete was placed?
Check with Your local Paint Store (Sherwin-Williams, etc) a lot will depend on the age of the concrete- the newer the worse time You will have, the older the better.
Concrete is always curing.
You can check with Home Depot, etc but they don’t just deal in coatings.
That’s ALL a paint Store does.
Prep is VERY IMPORTANT!!!
You will be using a 2 part coating but get the Pros at the Paint Store to help You.
If any of your guns have wood ‘furniture’, be careful not too keep the humidity TOO low. I’ve heard it can cause the wood to dry out and crack over a long period of time if the air is too dry. I don’t have this problem as ALL of my firearms have black plastic/polymer that makes them look “dangerous” to Liberals and idiots(please pardon the redundancy).
At minimum, an epoxy-based paint (pricey) and a good dehumidifier after it's applied.
If it's a new-ish pour, you'll need to wait for it to fully cure .. do a web search on recommended times.
Regardless how smoothly it was troweled, etching is recommended before any paint's applied .. etching = acid solution, most commonly muriatic.
Conversely, if the basement space isn't used for much beside storage and the moisture isn't such that things fall apart down there,
investing in a good 70 quart dehumidifier (w/ hose > floor drain) may be enough to obviate the need for messing with paint, etc.
My Garands I have oiled with unboiled linseed oil, as with the carbines and 1903s....others have been sealed pretty well, too. In the 10 years I’ve been doing this, no cracks or splits yet...(fingers crossed):o)
Use a two part epoxy paint it’s kind of expensive but in the long run it will last. I know Sherwin William has it but Home Depot and Menards and Lowes probably have it too.
Good advice regarding the local Paint Stores. Most of the people at ‘Big Box’ type hardware stores tend to not have any real idea about what they’re selling, and earn a little over minimum wage. I believe the only requirement to work in those places is having the ability to lift 20lbs, give authoritative bullshit answers, and fog a mirror. Hiring people that have actual real knowledge of their in-store departments would cut into profit margins, which are about ALL that matter for such places.....
Keep in mind that if you are having moisture being drawn through the concrete due to temperature/humidity differentials, putting a barrier seal is difficult to completely stop.
A low quality product may only make your problem harder to fix in that the moisture may build up behind an inadequate seal. That "paint" may then make it tougher to put down a better product later.
My point, based upon my father's experience with the same problem, is don't try to cut corners on your first attempt. It will make the real fix that much harder.
Do your research. Some folks have found more success running dehumidifiers in the basement.
My dad didn't find anything that worked until he spent the money on a good epoxy-type paint (expensive and a challenge to lay down quickly before it cures). The two cheaper types he tried first only created him more problems as they split and cracked as the moisture built up behind them from inadequate sealing.
They worked at first, but did not last over time. And then they had to be fully removed to get a good seal for the next product.
Poor cleaning of the surface will likely prevent good sealing as well. The best is an acid product made for cleaning concrete prior to sealing. I used these in factories where I coated floors to help with cleaning. Eventually I convinced my Dad to try what I suggested, but only after a couple years of failure with lessor products.
Good Luck! It can be a big job. Be SURE to get force ventilation through your basement (window fans) before the acid clean or the epoxy paint. You don't want to pass out down there in it, nor do you want those fumes lingering in your house.
If it’s just for moisture sealing, most hardware stores carry UGL Drylock, which works well for sealing. I’d use a 2-part epoxy on the floor if it’s not going to have any kind of floor covering laid down over the concrete.
drylock sealing paint, with a 2 part epoxy pour over it but only after it’s cured and been through at least 2 full years of seasonal changes.
I am a water damage restoration business owner, and I do mold inspections and testing in homes and businesses.
1. Ground water will travel through concrete.
2. Gravity is the answer... not sealant. Over time, the sealant will fail, and water can still enter through small cracks or pits. The only way to properly seal a concrete basement is on the OUTSIDE of the concrete. not the inside.
3. Contact a basement waterproofing professional. We have one here that uses a method of digging a 4” trough around the perimeter of the area and channeling the water to a sump pump. Water that effervesces through exterior walls travels down to the trough. Water that would otherwise effervesce up through the floor will find it’s way to the sump basin instead.
4. Avoid installing wood based products such as sheetrock in the basement. If you want to use wood finishing materials in the basement, use cedar or other mold resistant materials.
5. Keep a dehumidifier operating in the basement. A good one that moves about 50-75 pints a day can be purchased at Lowes for under $300.00
Stay away from Rustoleum’s “Restore” deck & concrete sealer!
I spent the better part of last summer preparing & painting our 800+ square foot deck with this crap. Very expensive and time consuming. I strictly followed the directions for application and it gave us a non-skid surface that looked great. That lasted until the first freeze and then started coming off in big chunks. The next rain dissolved the paint into a chocolate pudding texture that our new puppy took a liking to.
Called Rustoleum customer service and they issued a full refund ($450.00) without argument. To my surprise, two months later Fed-Ex delivered 25 gallons + rollers at no charge.
The product is total junk and should be pulled from the market. Hopefully I can find an 0bama voter to sell it to!
Reviews from other customers can be found here:
Good luck with your problem....
For researching methods, see articles at buildingscience.com: