Hi, I'm new to the forum. Looks like a great site.
I put up a shed/garage in my back yard about 4 years ago. The building turned out real nice. Problem is, the floor's been damp since day #1. It's that way year 'round. The building is 20' x 20' on a concrete slab. The slab is 1' thick at the perimeter, 4"-6" thick elsewhere, laid on top of compacted gravel, no vapor barrier. It sits at the highest point in my relatively flat yard. The soil is clay. The building is not plumbed, there are no water lines nearby, and the area did not seem wet before or during excavation. The guy who built it for me is long gone.
The bare concrete is always slightly damp, and efflorescence appears all over. The combination of moisture and alkalinity has caused damage to the bright metal surfaces on the small collection of motorcycles that I store in the shed. Because of this problem, I have not bothered to finish the interior walls or add wiring.
I had hoped to leave the floor in bare concrete, but it was just too much of a problem.
I tried to seal it w/this stuff:
http://www.moxie-intl.com/moxie1500.htm
Then I painted it w/this 2-part epoxy:
http://www.rustoleum.com/CBGProduct.asp?pid=16
The paint stuck for about 6 months, and then flaked off.
This all seems like a ground water problem, but here's the really odd part that might lead to a different answer. When the floor was poured, they ran out of concrete about 3/4 of the way through the job. The builder called out for more concrete, which I believe was delivered from another plant, maybe even a different vendor. The area of the floor that was poured in the 2nd batch dried fine, and the paint has stuck to it w/no problems.
Does this point to a problem w/the 1st batch of concrete? Is it possible that it never cured completely?
At this point the building is worse than useless to me. It is actively damaging the toys that I built it to house. I'm going to put everything into a storage unit until I figure this out. It would be nice if I could find a product to seal the floor, but I don't know were to turn. That Moxie stuff shown in the link above seems to be so much snake oil. Does anyone make a surface coating that will stick to wet concrete? I suppose I could lay out some 6 mil plastic and pour another thin slab on top, but that would create a big problem w/the door openings. Raising the building would be a real pain in the rear end.
Help!!!
Here are some photos.
I put up a shed/garage in my back yard about 4 years ago. The building turned out real nice. Problem is, the floor's been damp since day #1. It's that way year 'round. The building is 20' x 20' on a concrete slab. The slab is 1' thick at the perimeter, 4"-6" thick elsewhere, laid on top of compacted gravel, no vapor barrier. It sits at the highest point in my relatively flat yard. The soil is clay. The building is not plumbed, there are no water lines nearby, and the area did not seem wet before or during excavation. The guy who built it for me is long gone.
The bare concrete is always slightly damp, and efflorescence appears all over. The combination of moisture and alkalinity has caused damage to the bright metal surfaces on the small collection of motorcycles that I store in the shed. Because of this problem, I have not bothered to finish the interior walls or add wiring.
I had hoped to leave the floor in bare concrete, but it was just too much of a problem.
I tried to seal it w/this stuff:
http://www.moxie-intl.com/moxie1500.htm
Then I painted it w/this 2-part epoxy:
http://www.rustoleum.com/CBGProduct.asp?pid=16
The paint stuck for about 6 months, and then flaked off.
This all seems like a ground water problem, but here's the really odd part that might lead to a different answer. When the floor was poured, they ran out of concrete about 3/4 of the way through the job. The builder called out for more concrete, which I believe was delivered from another plant, maybe even a different vendor. The area of the floor that was poured in the 2nd batch dried fine, and the paint has stuck to it w/no problems.
Does this point to a problem w/the 1st batch of concrete? Is it possible that it never cured completely?
At this point the building is worse than useless to me. It is actively damaging the toys that I built it to house. I'm going to put everything into a storage unit until I figure this out. It would be nice if I could find a product to seal the floor, but I don't know were to turn. That Moxie stuff shown in the link above seems to be so much snake oil. Does anyone make a surface coating that will stick to wet concrete? I suppose I could lay out some 6 mil plastic and pour another thin slab on top, but that would create a big problem w/the door openings. Raising the building would be a real pain in the rear end.
Help!!!
Here are some photos.