Concrete issue – trapped water between foundation and vapor barrier
I have a problem with my house where water is trapped between the plastic vapor barrier and the foundation. The water is finding its way out of the foundation by way of the outside of the house where the foundation meets the house. The water is not leaking out, its coming out as vapor and deteroriating the concrete where its coming out. The water was trapped on top of the barrier about 10 years ago when I experienced a slab leak and the plumber made a mistake and cut the vapor barrier and didn’t fix the pipe and then filled the hole in the foundation with concrete. The leak continued and filled the top of the vapor barrier with water. Now, the water is trying to get out as vapor and is breaking down the concrete in certain areas of the exterior foundation. I was wondering what options I have to fix this:
1) cut a couple of holes in the foundation in the house and place some sucking fans on the holes to pull out the water vapor? Maybe one fan is blowing into one hole and another is sucking out of another hole in different parts of the house.
2) drill holes from the house’s outside foundation where the foundation meets the house and where the water is deterioratting the concrete to provide an easier path for the vapor to escape?
3) Are there any experts that can provide direct assistance on this issue?
Thanks for any ideas on this
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Replies
Bob,
1. Please describe your foundation. It sounds like a slab on grade, but I want to be sure it's not a crawl space or a basement foundation.
2. Water does not usually cause deterioration of concrete, so something else is going on. What's your climate?
As a New Englander, I have dealt with water issues in basements and homes my whole life, professionally and personally. I do not recommend more penetrations of the foundation. Water seeks the path of least resistance. That said, ensure no more water can enter the scenario you described artificially. Provide a warmer, drier atmosphere than that of the exterior of the foundation walls. Heat, dehumidification and make-up air may all be required. Patience will definitely be a key ingredient! Good luck!
Thanks for the responses to the question here. The foundation is a slab on grade. So water doesn't typically deteriorate concrete? That's good news. Something else must be causing the concrete to break apart on the exterior. I'll have to investigate this. As for cutting the concrete/drilling holes, that was an idea to try to release the water. I'll have to do some more research on how to get the water out.
Also, I live in So California and the climate is usually warm and dry.
Bob,
Do you see any evidence for your complicated theory about trapped water and water vapor escaping from your foundation? Or is the only evidence the deteriorated concrete?
BSC has publsihed on CA builders putting sand over the poly and then pouring a slab. If this was done then a path for water was created between you vapor barrier and the slab. I would go to the BSC webiste and find the article. Dont remember if the gave a solution other than dont do it.