Our acid-stained concrete floor is turning white. Last August we started construction on our new home in WI. The ground floor is a poured slab with radiant heat and a 30″x 30″ scored grid pattern through -out. After 3 months a dark brown acid stain (Brickform) was applied, followed by a concrete sealer. A couple of weeks ago the floor started to “cloud” up. It began in spots and is now spreading. I talked to Brickform and they thought that moisture is coming up through the slab and the sealer was probably put on too thick so that the moisture is not escaping. They suggested stripping the sealer and resealing. In addition the floor is “sweating” quite abit, especially near load-bearing walls.
If we strip the floor and reseal will this take care of the problem? Or will it happen again next Spring? Can we go over the floor with tile or wood? And if we do, are we creating any additional problems? Any insight would be greatly appreciated.
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You can check if there's moisture coming up through the slab by sealing a foot square piece of poly sheeting to the floor with tape on all four sides and looking for condensation in a day or so. If that's the case, sounds like you'd need to solve that problem before you could do much of anything safely whether that is restaining it or putting in another floor...
Is there any chance of a leak in the radiant tubing?
Edited 6/8/2004 1:56 pm ET by PaulB
Paul, I think he has already done a moisture test. The sealer is probably as effective as the visqueen.
You might be right about the radiant leak.
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Hi Paul,
I'll do the poly test tonight. I don't think it's the radiant tubing. If it was, then I think there would be some kind of seepage in the saw cuts (they're 1" deep). The clouding isn't isolated to 1 spot, rather it is several large patches scattered throughout. The other odd thing is that 1" on both sides of the saw cuts have the normal color making almost a border around the cloudy white color.
"Last August we started construction on our new home in WI. The ground floor is a poured slab with radiant heat and a 30"x 30" scored grid pattern through -out. After 3 months a dark brown acid stain (Brickform) was applied, followed by a concrete sealer. A couple of weeks ago the floor started to "cloud" up. It began in spots and is now spreading. I talked to Brickform and they thought that moisture is coming up through the slab and the sealer was probably put on too thick so that the moisture is not escaping."
Will Ryan home by chance?
Jon
Nope not a Will Ryan home. Our builders are currently trying to work with the subs who did the flatwork and staining. But I'm not real confident in any solution that sub might come up with.
Was there no VB or poly placed under the slab before it was poured? If not, then ground water can be wicking up through it and causing effloressence
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I just checked the construction photos and there is a layer of poly. On top of the poly is a layer of rigid foam(2"blue) with radiant coils stapled to the insulation. The rigid foam is not continuous . The cloudy appearance looks like effloressence to me - but I'm not an expert.
Any chance the staples penetrated the VB?
What is the water table like? It's a wet year here and high, making drainage difficult at some places.
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I don't think the staples are long enough to go all the way through the 2" insulation. However, looking closer, it looks like there are a couple of open areas in the poly where column footings were to be poured. I can't tell in the photos how tight the poly is to the frost walls. It has rained alot here and we are pretty saturated. Bedrock is 5' below the surface so it takes a while to drain. Assuming this is where the moisture is coming from, is there anyway of dealing with this? Is it adviseable to go over the concrete with tile?
if minor subterranean moisture is the cause, then I would not suppose it would hurt clay or ceramic tiles. You might still find the moisture migration but the heat should keep it from condensing and causing other symptoms.
If it is a more major water problem then you might need to tunnel under with drain to pick up the water and lead it to daylight or a sump pit. I wouldn't worry about that based on what I read here so far.
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Was the sealer applied too soon? Perhaps the concrete had not fully cured?
Latticrete makes a crack isolation membrane that would probably work as a vappor barrier as weel if you end up tiling.
Eric