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Mold/Mold, moisture in crawl space


Hello Daniel,

My house has water in the crawlspace coming through the foundation.  Whoever built the house in 1991 installed a french drain but while digging out around the outside foundation to make room for ductwork for a new heat pump, I discovered the french drain was all clogged up with red clay (which is normal in this area).  So each time it rains water can not enter the drain, so it gets in, and mold is beginning to develop.  

I have had 2 estimates for crawlspace waterproofing and both of them suggested the encapsulating process with sump pumps and a dehumidifier.  My crawlspace has very limited head room, about 3 feet.  So I feel the easiest fix would be to address the outside issues instead, to keep water out.  I am no expert, but common sense tells me this would be easier.

What is your opinion?  I have not had anyone, at least so far,  suggest working from the outside, opting instead to work inside the crawlspace where it would be 10 times more difficult.  Not to mention more costly by hiring an electrician to provide power for the sump pumps, the sump pumps themselves, the water lines, dehumidifier, etc.,  and the very cramped space making it hard to dig trenches under the house.  

I welcome any ideas you may have.  


Hi Gary sounds like a serious problem from what you described. To prevent mold growth you need to stop the water from getting into the crawlspace.Also moisture in the air inside the crawl space needs to be eliminated. So a dehumidifier inside the space will be needed regardless of what you do to stop the water. Make sure the dehumidifier drains outside the crawlspace when it is installed.Now regarding the water and how to prevent it from getting inside. You will need to dig out against the foundation and install a high quality perimeter drain that will not get clogged up with clay again. I am not an expert on drains so you need to consult with a contractor who has a 100% successful track record installing such drainage systems. While the perimeter of the crawl space is excavated I do recommend a rubber membrane be attached to the foundation wall be fore it is back-filled. The contractor should include this in his scope of work.
Now there may be mold inside the crawlspace walls and other areas so the mold needs to be killed.
I can help you understand how to go about that if need be. I wish you good luck! Daniel


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Daniel Cetrone


I am probably able to help you understand the mold problem you are having, why it is happening and what to do about it! Most mold problems small, thus easy and simple to remediate. Large mold problems are a different case! They can cause an entire home to be unhabitable!


I am a residentail contractor with 29 years or experience remodeling, repairing and building homes. Throughout many of those I handled insurance damage restoration and remediation projects.

Fitchburg State College, Secondary Education Major, Industrial Ars specialty 1975 Water Damage Restoration certification from (IICRC) Institute of Inspection, Cleaning and Restoration Certification 2000

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