I worked on an exterior sump pump recently for a client and got to thinking this may be just what I need for a rental that I own. The sump pit was about 10 or 12 feet deep, 24″ in diameter and had a cover that bolted on. It was made of plastic and was located just outside of the house about 30″ from the foundation wall. There were two plastic drain tile that emptied into the pit. Has anyone ever installed one of these. I have a house built in the 1950’s with a sump pit in the crawl space that is only about 18″ deep. The floor of the crawl is clay and always seems like it is wet. I thought if I installed one of these deep exterior sump pits it would lower the water table under the house over time and it would dry out. Would this work or would I be better off digging a new sump pit in the crawl space? There is no drain tile around the foundation.
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In general I like the idea of an exterior sump.
BUT, even DRY dirt will release lots of moisture into the crawlspace.
The solution is is to cover the floor of the crawlspace with poly.
William the Geezer, the sequel to Billy the Kid - Shoe
With clay soil, tough to bring down the water table as the water is trapped and runs thru cracks etc. If sandy soil, this would work well (called a well point)
Your crawl space moisture is likely from drainage and since there is no draintile, no way to take the water to the pit.
I'd go thru gutters, extending downspouts, exterior grade, all the 1st items to make sure that drainage is the best it can be and then if that doesnt work, i'd bite the bullet and install a draintile system. Otherwise, I think you are just chasing your tail.