OT, Shop floor concrete coatings

[BOSS351]

Ok, I was planning on putting an Epoxy floor coating on my new concrete shop floor (1 month old). The shop is 960 sqft. I was looking at an epoxy by Behr ( http://www.behr.com/behrx/act/view/p...tings&catId=16 ) until I realized it is just a paint. Then looked into the Rustoleum PRO 2 part epoxy kit (would take 2 at $118 each). This seems to have gotten good reviews at Garage Junkies, but I do not have a vapor barrier under the floor (advised against it by several concrete guys locally) and it says not to use it on floors that sweat. The whole reason I wanted to coat the floor was to stop condensation from forming on the underside of cars I park in it. Also, found out a lot of the coated floors around here still get the condensation forming, and get really slick. Also, with welding and cutting (O/A) damage to the coating is a concern.

This is a long winded way of asking what you all use and to point out the fact that you can not use these coatings on floor that sweats to others considering doing this.

In the end I have decided to leave the floor bare concrete.

[houlibar]

Here in California I havn't seen very many painted garage floors. At work we painted our shop floor with a 2 part epoxy. I can't think of the brand right now, but they offer two versions. One called 400 and the other called 700. The 700 is I believe the most expensive. A lot higher than the price you quoted. But it's really tough stuff. Even the spot on the floor under the vice where we weld has held up with all the hot slag dripping on it. Sure, it's discolored, but it's not peeled and seems to be quite intact.

OT, but meant to ask: does the sweating concrete and paint quideline apply to basement walls too? We don't have basements in California. But I love checking out basements when we visit the wife's family in Michigan. (UP)

[BOSS351]

There is paint specifically for basements (I believe Drylok is one). They must be able to hold up to hydrostatic pressure, which seems to be the problem for the garage coatings.

[Pumpkinhead]

We don't have basements

oooooooh, a chill just ran up my spine!

[houlibar]

We don't have basements

Well yeah, why do you think there are so many retards roaming the streets here?

[daimon1054]

1 month old is to new to coat everything I read says 90 days min and as much as 1 year is better. As to no vapor barrior who ever told you not to was a dip wad. I don't know what will stop sweating, I would call the tech lines for all these products and see what they say.

[JohnV]

I have heard good things about the floor paint from Griots Garage. Of course preparation of the floor is the key. They have instructions on the website on how the floor needs to be prepped. The link to it is below.

http://www.griotsgarage.com/catalog....3080&SKU=90011

John

[dda52]

I think......wait a minute....there. I switched hats. Speaking as a concrete contractor now, ..I think no vapor barrier will be the downfall of any coating you come across. Water can build up behind anything you put down and make it peel up. It is the vapor wicking action you need to stop before any coating will work. I looked at my books I have on hand...all the waterproofing admixtures and coatings in front of me specifically do not inhibit vapor transfer. There may be one out there though. The best thing would be to check with a local concrete chemical supplier and see what they can do for you. If it exists, you would be getting some kind of moisture sealer and epoxy coating [B]SYSTEM.[/B] You must get the system if it exists. Never mix system components with another brand or system...it will not work, period. The systems have a balanced chemical make up that tolerates each other. Add a stranger to the mix and the results can be very ugly. Ugly can mean it looks bad to as far as it starts to eat up the surface of the floor. Not good. Be very sure you have a good grip on something when you price the things...I have seen some commercial coatings that ran around $120 a quart. They were light years above and beyond what you can get from the box stores, though.

IMO, I think bare floors are best. They may not look as good, but you don't have to worry about them so much. Bare may be better in your case.


EDIT: FWIW, concrete is considered "cured" at 28 days. Lots to most coatings are engineered to work properly at that cure rate. Local conditions, temp variations, water content of the concrete, water reducing agents used, air entrianment used in the mix....all these and more can influence the cure rate. It is best to wait as long as possible when applying coatings. 60 - 90 days would be good insurance against failure. More is always better in this case.

[James D. Clark]

Concrete floor condensation or sweating is caused by the floor being colder than the air and high humidity. High ground moisture under the floor will also keep the floor cooler than the air and cause sweating. Either some way of artifically heating the floor to keep the floor temperature near the air temperature or dehumidifying the air or just waiting for the floor temperature to match the air temperature is about all that can be done. A surface treatment won't stop the condensation.

[BOSS351]

Thanks for the replies everyone. Pretty much reinforces my decision not to coat.

[toolaholic]

finishers hate plastic ,and use to stab it full of holes if i wasn,t around.
the one and only reason. it holds in the mix water and takes for ever to go off!
i started building back east, and all my basements had plastic.

you were done wrong!

[dda52]

For the record, I don't hate plastic. It serves a very important purpose...esp this time of year. It was 104 in the shade at 3:30 today. I say keep that water in as long as possible. Otherwise I'll have to put my tennies on to keep up with it. ( I've got some parking lot coming up that is gonna be like that I'm afraid. )

[Frank S]

As far as preventing condensation on the underside of my car I just use a sheet of 6mil plastic on the floor. It makes cleanup easy too (from oil drips, etc.). Cheap to replace and easily removed if you need to weld.

[Sundown]

We don't have no stinkin moisture here, the humidity was all the way up to 10% or so the last few days. The only time I can get the concrete wet is to water it with a hose, frowned upon by the mayor as wasting his water.

[BOSS351]

At this point I was planning on putting some cardboard down under the car that will be stored long term. The plastic is a good idea, I'll keep my eyes open for some freebies along that line.

As for the vapor barrier, I spoke with 4 or 5 contractors (general, builder, and conctete) and all said it's not usually done up here, although I never was given an explanation why not. Not arguing as I don't know, but may the temp extremes here have an influence ( -20*F to 100*F w/high humidity)? I see most who have responded are in the South West and don't have the temp extremes. Just wondering. I am happy with the floor as is and was given a very good deal on it.

Just trying to learn.

Thanks everyone