There are several things you can do, but my first suggestion is to make sure there is a layer of plastic on the crawl space floor. This will greatly reduce the humidity level in the crawl space.
It's inexpensive at any hardware store. Just ask for 6-mil plastic sheet for a crawl space.
Insulation certainly wouldn't hurt your heating bills.

[This message has been edited by rpxlpx (edited August 20, 2002).]

I've considered putting down a layer of plastic too to keep the moisture from the house, however, I am concerned - wouldn't the moisture just be trapped in the dirt under the house, staying soggy longer?

That is the whole point....keep the moisture out of the crawl space and in the soil where it does no damage.

Glenn

To supplement what they wrote, gravity is your friend, here. Although the moisture under the sheet will be there, it will "want" to go down with gravity, not up against gravity, unless there is some sort of forceful pressure pushing it up from below or it tries to evaporate into drier air. The plastic sheet creates a barrier that serparates the moisture in the ground from the air in the basement so that it does not evaporate. In other words, the sheet will merely let the water "know" that it can't evaporate there in the crawl space and should just keep going down with gravity to the water table.

Using a dehumidifier will help eliminate the musty smell, too. It will dry the air faster than the moisture evaporates upwards. Again, only a minimal amount of water should normally get there because gravity is pulling it down, not up.

Cleaning the crawl space and other spaces with bleach every once in a while will also kill any mold causing the musty smell. IF it is a disgusting crawl space, all the better to clean it, even if only to dump bleach on it and let it soak/penetrate into the foundation and kill 100 years of potentially built-up mold.

And, yes, you should patch any finger-wide holes in your flooring. Chances are that foot traffic will splinter the floorboards and make the hole bigger with time. Moreover, it is always best to seal the crawl space off from the living space.

Is your CS wet or just smell damp? I am having the same problems you are and have read numerous websites so I think I am a pro now. I am a new home owner and have never had to deal with these problems. My problem is easy. I need gutters and a slope away from the house. (not towards it) (idiot of the year for not spending time outside looking at the slope of my yard) One website said to tape a piece of aluminum foil to the wall of the CS. Seal it on all four sides. In a week or so go back and look at it. If you have moisture on the side showing your problem is coming from the ground or inside. If the moisture is between the foil and wall it is seeping in from outside. In which case you need gutters, a better slope away from your house or dampproof the walls of the foundation. One website I was at said don not put plastic down until you have solved where your water is coming from. Hope I helped you.