Painting Concrete

[Chillbilly]

In answer to TWOGYPSIES, this is not only my RV site but also my home for the winter. I appreciate all the comments. Unfortunately, I cannot use the muratic acid here, but can probably get away with using clorox. Many of you mentioned using a stain rather than a paint. Will it hold up longer? How can I prevent the mildew from coming back? Thanks again!

[bamaboy473]

Originally Posted by Chillbilly

I cannot use the muratic acid here, but can probably get away with using clorox. Many of you mentioned using a stain rather than a paint. Will it hold up longer? How can I prevent the mildew from coming back? Thanks again!

If your slab is older and cracked, then Florida weather and ground make-up will cause moisture to come up through the slab...so I question sealing at all. IMO, that will caused hydrostatic pressure to blister anything that isn't porous.

I also question using muriatic acid for fear of spalling on an old slab. All you want to do is go low-tech; Clean it well, get it DRY, apply a porous substance like stain.

We did our pool's deck three years ago and it's fine. Two coats was fine. Your results may differ.

[bamaboy473]

P.S. since concrete is so different from one slab to another, the BEST advice might come from your neighbors that tried one thing or another. You'll be able to see what worked best....but even those results are suspect because you don't know about the surface prep or drying conditions.

Anyway, you can paint over stain if you want to later on. You can't stain over paint, and if it blisters, you've just bought into a royal mess. Finally, wet stained concrete isn't slippery.

Let us know how it turns out.

[DonavonP]

"Wet and Forget" is suppose to work on mold, mildew, etc.

[papaw.1]

This is just MHO but,I would Pressure wash really good and wait 2 days until completely dry and use The Bear concrete stain with 2 good coats and forget it.That will work.I did this for years.Let us old gizzers know how it turns out.

[pops2]

writing b4 I said to use muratic acid which is hydrochloric acid. they are one and the same, but dilute 50/50 with water then pressure wash.
there should be no reason why you can not use muratic acid where you are as when you use it and are finished the job the ratio of acid to water is miniscule.
We used to wash our mixer trucks with muratic acid mix to remove excess concrete from the paint.

the reason that you need to etch the concrete is to remove the resid ent concrete dust and so you will have a good substrate for the coatings to adhere to.

good suggestion in regard to use stain first as it will absorb into the concrete as paint will only sit on the surface unless it is especially for sealing and coloring the concrete.

[bamaboy473]

Originally Posted by pops2

the reason that you need to etch the concrete is to remove the resid ent concrete dust and so you will have a good substrate for the coatings to adhere to.

Hello expert, from a non-expert We've always considered that using muriatic acid on old concrete can increase spalling, as it gets under the surface and loosens part of it. Have I been under the wrong assumption on this?

Using Clorox/Jomex to kill mold and clean the surface, followed by pressure-washing is what we do. Would you suggest using acid in place of...or in addition to... the clorox and Jomex?

[Scooter]

Rick and Sandy....I sent you a P.M.

[Bamaman]

If your concrete is rough, you can fill up the cracks and then roll it with a product like Rustoleum 10x. Home Depot also has a product that's about the same, and I understand customers are happier with it than the Rustoleum product. It's often used on wood decks, too.

I applied H&C solvent based concrete stain to my slick finish concrete screen porch last week. I'll be adding a second coat as soon as we have a good dry day. The negative about concrete stains is you cannot park any rubber tire on them. Any surface with tires on it (garages, airplane hangers, etc.) require an epoxy floor. They're not badly priced now that the big box paint companies have got into the epoxy business.

[DegoRed]

billy, let me offer you an alternate solution, that I feel is a better solution.

I do agree that Muratic acid is the best way to clean concrete, however, it can have some unintended consequences. Muratic would be my first choice, but since you said you can't use it, here is another alternative. This Cleaner is very powerful, if you put this on your car and came back 30 minutes later, it would eat the paint off your car.

I would do this:
1. pressure was your slab to clean it.
2. mix this purple cleaner up with some water in a 5 gallon bucket.
3. scrub you slab with a big scrub brush on a pole, and let is sit for little while
4. re-pressure was your slab to clean it
5. possible redo in trouble areas if needed

Now that you have a clean slab, the choice is yours on what to use. I would not waste my money on any paints, as they will come off real quickly. I would stain the slab. Here is the rub, there are several concrete stains on the market now, but not all are created equally. Use an ACID based stain, those are the only ones that work and hold up well. The one we use a lot is Scofield.

Staining concrete is so easy. Just mix up the stain in a cheap plastic sprayer. Pump up sprayer and spray on. Stay off slab for 24 hours. Your done. The reason to use ACID based stain, is that it etches into the concrete, so your not just changing the top appearance, you are actually changing the top layer of concrete. Water based and oil based stains will disappear fairly quickly in the weather, where as the ACID based are permanent. The acid based stains don't really cost any more than the others, maybe a buck to two max. Also, go a bit darker than you think you might want, the stain always seems to come out just a hair lighter than you think it will.

Feel free to PM for help on this. Have done a lot of slabs and counter tops over the years, its really very simple.

After typing this up, I hit youtube, there is a ton of info on this For Example also learned not to use an acid based cleaner, which I did not know. Good Luck!

[TQ60]

For cleaning old concrete the best bang for the buck is bleach and tide.

Look for an old floor polisher as they can be found for a few bucks.

Get a tank sprayer and mix very strong bleach and saturate the concrete late night and let it soak overnight. (Test in a corner first)

In the morning spray it again and if yiu found a scrubber give it a round and rinse off well.

Let it dry to see how it looks.

Repeat with tide to remove what the bleach left and to remove what is left of bleach.

Check with local building department for their suggestions as to best ways to seal your pad.

They will be aware of what is legal and not as well as what may or may not work.

Others already stated moisture will rise from bottom so options very limited.

[bamaboy473]

Originally Posted by Scooter

Rick and Sandy....I sent you a P.M.

Yes, I got it and responded. Hope it helped.

[bamaboy473]

Our deck was 10 years old when I cleaned and stained it. Going on year 4 in a southern Alabama atmosphere, there are some spots that have lifted a bit from aggressive pressure washing (no sunlight on the area next to the house) Lifted isn't a good word because it's more like the small areas (less than dime-sized) are just gone; blown away by the psi. The stain on the concrete is there for the long haul, IMO.

We used Behr semi-transparent Concrete Stain, Latex.

I'm not sold on either acid or latex, so acid might be better (but can't be much better than what we used). We didn't want acid due to ten years of plantings, flowers, shrubbery that we didn't want to die. That's the only reason.

I'm going to get several gallons of this stain in the fall, and over-spray what's down. Hope it sticks.

P.S. that's why I wouldn't seal anything. once you seal it, applying succeeding layers becomes incredibly difficult because you have to somehow remove the sealant.