Is cement waterproof ?

[jclary]

Interesting. I just had a new 24 x 36 garage built and I'm pretty sure no moisture barrier was used beneath it. On Mrs. Bob's 2/3 it's 4000 psi and my modest 1/3 "Studebaker side" it's 5000 psi. I've been told I need to put a sealer on the floor. True? If so, what type/brand is recommended? I'm not interested in those Epoxy coatings as I've yet to see one last for more than a year here in Minne-snow-tah, land o' 10,000 MinnDot salt piles.

Bob, from the "far from expert" on this subject...you are waaay ahead of my dirt floor man cave. I have some old conveyor belts placed down as a moisture barrier. Before you go anal and lie awake worrying about this, I would suggest you take a little time and monitor your floor. You could go out and check the chassis under your car and look for "sweating" and condensation. If it stays wet, then you could have a problem that needs to be addressed. However, I would think that under normal circumstances, with good air circulation, a little moisture that quickly evaporates and dissipates, would be acceptable.

My (suspect) understanding is that sealers are to protect the concrete from bad stuff you might spill on it or do to the concrete, not for protecting the stuff placed on the concrete. For now, I'll sit back and wait for the real experts to comment.

[Skip Lackie]

My (suspect) understanding is that sealers are to protect the concrete from bad stuff you might spill on it or do to the concrete, not for protecting the stuff placed on the concrete. For now, I'll sit back and wait for the real experts to comment.

My understanding is the same as John's. I had the top of my garage floor sealed when I had it built ten years ago. Water runs right off and oil can be wiped up easily. But gasoline softens the sealer and makes it kinda sticky. And lacquer thinner removes the sealer instantly. There may be better products on the market today --it might be worthwhile to check the specs to see how impervious the various seals really are.

[JBOYLE]

I've heard in Chicago they make overshoes out of the stuff.
So it must be waterproof.

[BShaw]

My understanding is the same as John's. I had the top of my garage floor sealed when I had it built ten years ago. Water runs right off and oil can be wiped up easily. But gasoline softens the sealer and makes it kinda sticky. And lacquer thinner removes the sealer instantly. There may be better products on the market today --it might be worthwhile to check the specs to see how impervious the various seals really are.

I went to Menards this afternoon. They only had one sealer, Rustoleum brand, and the salesperson, while friendly and eager, had no product knowledge on that particular item. I'll spend some quality time with Google tonight and see what the 'net says.

[TXmark]

well they build boats out of concrete, google it and see. I remember as a boy reading about concrete boats in Popular Science

[jclary]

well they build boats out of concrete, google it and see. I remember as a boy reading abpot concrete boats in Popular Science

I have seen some of those. However, not even boats are "waterproof!" If they were, the huge industry manufacturing bilge pumps would not exist.