Water"proofing" Dirt Crawlspace

I live in Southeast US and have recently purchased a 1920's Bungalow in need of some work. In this particular case, the dirt crawlspace has been taking on water in heavy rains. I have already added gutters and downspouts to take away the majority of the moisture away from the house, but it still finds its way in. I do not care to make the crawlspace a useful area, but I would like to keep the wetness down. I already have plastic lining the floor and have considered making a trench-sump to control the water's flow.
Any suggestions?

 

chief,

I will answer this based on information that may be relevant to your area. This is from rlcengineering so take it for what it is worth, I think it is good information.

Almost 70% of the houses in South Carolina have crawl space foundations. We build more crawl space foundations than any other state in the country. Yet we continue to have problems with our crawl spaces. These problems include mold and decay, elevated radon levels, and termite and other pest concerns. We see condensation on ductwork, mold on joists, termite and wood boring beetle damage and cupped hardwood floors. Our current solution is to increase ventilation of the crawl space.

Since moisture is such an issue in crawl spaces, addressing moisture issues is the first priority in closing a crawl space. Exterior water must be directed away from the foundation with proper grading of the lot and proper handling of roof runoff. Crawl space soil should be completely covered with a vapor retarder. Capillary moisture movement should be restricted using either capillary breaks under piers and foundation walls, or by covering foundation walls and piers with a vapor retarder. Foundation walls can be insulated rather than floors over crawl spaces for enhanced thermal performance. In some instances, a dehumidifier will need to be added to the crawl space because of the complexity of home designs and the psychrometrics involved. Specific details for a sealed crawl space can be found at this web site;

http://www.rlcengineering.com/csspecs.htm

In a good crawl space, with good moisture control in and around the foundation, moisture problems won't exist. Interior moisture levels will be more stable. Hardwood floors and other interior wood will be more stable and less prone to shrinkage and warping. Energy costs will be lower and duct condensation will be eliminated.

Hope this helps!

 

You might take a look at the grading around the foundation to be sure that it will guide water away from the house.

One more step.

 

chfite,

That was in my post...

"Exterior water must be directed away from the foundation with proper grading of the lot and proper handling of roof runoff. "

 

Oops.

 

chfite,

That's ok...we know how it is getting old! Thanks for the input though!

Your Fellow Moderator!