# Any concrete/cement pros out there?



## Bert H (Mar 2, 2004)

We have a detached garage that I'd eventually like to turn into an office. But there is a problem with the concrete slab flooring. It seems that when it was poured they must have been cheap with one of the raw materials because it scrapes off. It's like a coarse sandpaper. It's not like it's crumbling, but I could scrape it with my foot if I went at it long enough. 

What I'd like to know is if they make some kind of sealer I can put on it to stop this slow, but sure breakdown, and also decrease the dust which would be produced from it. If possible, the goal is to eventually insulate it, and maybe put in a wall a/c unit for its final use.


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## gibmaker (Jan 3, 2007)

Does it appear that there are fibers protruding from the concrete or is it literally just breaking down and really powdery? If it is just flat out breaking down and becoming powdery you need to etch the concrete with muriatic acid to stop the efflorescence. If you can stop the efflorescence your best bet would be to get a moisture cured urethane and coat the floor, but only if you can stop the efflorescence, otherwise the urethane will fail. Pictures would help.


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## Bert H (Mar 2, 2004)

I'll take a close look when I get home about the fibers, also try to get a pic. I have a stupid question: what is efflorescence?


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## freydo (Jan 7, 2006)

Efflorescence, in chemistry, is the loss of water (or a solvent) of crystallization from a hydrated or solvated salt to the atmosphere on exposure to air. - quoting wikipedia 

to me this sounds like spawling, which is what the structural guys always refer to when describing concrete that had not cured properly. the concrete is easily chipped away. the temperature was probably too cold and it was not kept at a proper curing temperature.

you can try using a sealant, which may slow down the breakdown. but the worst case scenario is that you may have to replace the concrete.

but yes... if you post some pics, someone who is a structural engineer could probably tell you exactly what's wrong.


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## Dielectric (Oct 7, 2008)

my mother in laws slab was the same way. she contacted the contractor that poured it and they sealed it for free... i could gouge it with my finger nail.


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## gibmaker (Jan 3, 2007)

The main reason why the slab is doing this is because it sounds like it has a broom finish, they didn't trowel it well, so the cream of the concrete never got as hard as it should have. The efflorescence is basically salt leaching out of the concrete. Don't you live in Florida Bert? Temp wouldn't have been a problem. You don't need a structural engineer to help you, he may be able to tell you what is wrong, but unless he has a vast knowledge of the products available to fix the situation he may only be able to do just that, tell you what is wrong. I have been working for a company for the past 10 years that does industrial/ retail flooring, as well as retail and industrial paint and just about anything else you can think of, I answer these questions from 8-5 Mon-Sat. If you want to check out our web site here it is. http://parkercoatings.com/index.html


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