Help! My newly constructed concret cistern is leaking badly. I drained it completely an found cracks in the bottom. I dried it, calked the cracks with waterproof concrete/masonry calking, and refilled. It is still leaking over 10% of total capacity in just 3 days. Maybe it's seeping through the "waterproof cement" coating on the inside. Maybe I need to pour a new floor and waterproof it. My cistern is 8 feet long, 7 feet wide, 11 feet deep and the concrete walls are 4 inches thick. It is a buried cistern. Any recomendations?

-- Tom (redfernfarm@lisco.com), November 22, 1999

Answers

I've read about a material thats used for surface bonding cement block. In fact I think it was in countryside. In the example given you simply stack the block and apply the bonding material with a trowel I think. They built a tank with it so I assume it doesn't leak.

-- john leake (natlivent@pcpros.net), November 22, 1999.

Tom,

There is a product, I think it is called UGL, that is an epoxy type paint that is usually used to keep water from seeping into basements. Lumber Yards and larger hardware stores sometimes have a display set up with a waterproofed cinderblock coated with the stuff.

If it'll keep water from seeping in it should keep water from leaking out. I don't know if you can use it for the inside of potable water storage cisterns.

Hope this helps Cheers

-- Joseph F. Longshaw (deercreekfarm@juno.com), November 23, 1999.

my cistern is lined with rubber roofing - it DOESN'T leak - I designed the cistern to not include any seams - if you have to have seams to complete the shape make sure you use the proper cement for the rubber

-- kirby johnson (kirby@selco.lib.mn.us), November 23, 1999.

If it has a lid, make sure it is WELL ventilated before using ANY chemical ie epoxy.

-- Greg Sanderson (stonycft@worldpath.net), April 14, 2000.