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Sealing a Cistern

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My contractor took all my money now I need to seal my own cistern. It is poured concrete . There is no water in it might be damp though. How do i prepare it. How do I apply the first coat of Thoroseal how many coats any help

Topic starter Posted : September 5, 2010 3:40 pm
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Power wash it and pump/ vacuum it out.

Then mix the Thorough Seal as directed and roll a few layers on. I'm not an expert but that's worked for me. A little moisture doesn't hurt because it's a product that mixes with water and creates a cementatious seal. It applies pretty thick and a large brush should be used. Just slop it on. On the floor you can mop it on.

Posted : September 5, 2010 3:51 pm
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All cisterns will leak water out to the outside walls in a matter of a few years no matter how well the block/cement is prepared & sealed with sealant. We are having a custom made cistern liner installed sometime later this month (like a big bladder in your cistern) that is guaranteed to not leak for 20+yrs. After having our cistern sealed and then re-sealed all within 8 years, it's not worth the time & money to keep re-sealing it. We ordered our PVC cistern liner from DLM Plastics in Findlay, Ohio. The web site is

Jumbie -STX

Posted : September 5, 2010 4:48 pm
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