Crawl Space Moisture

I own a house the first time and need advice on maintaining my crawl space free of moisture and mold. We are in the South and allergies are a problem with my family. The crawl space openings sufficient or should I do something more?

We went through the problem of moisture and ventilation of the crawl space problem years ago. We found that there were conflicting views on the vents, barriers against moisture, sump pumps and adequate ventilation. We have been informed when we have studied more.

We found each household can have its own solutions, but the levels of moisture in the wood you say a lot. When humidity levels are more than 20%, decay is inevitable, but not yet rotten. Humidity levels over 28% means that the wood decay fungi is active (it feeds on the starch of your wood to rot there) and it is probable that the damage already visible. Fungi and mold do not grow or become active if levels are lower. Generally, the flow of air keeps the moisture levels down.

Here is a PDF publication Clemson University home care on levels of moisture and control to address:

http://virtual.clemson.edu/groups/psapublishing/PAGES/FYD/HL255.pdf

NC State also has one http://www.ces.ncsu.edu/depts/fcs/housing/pubs/fcs486.html

It's a good thing too. The Billion Dollar Thief: Moisture

http://virtual.clemson.edu/groups/psapublishing/PAGES/FYD/HL239.pdf

A non-pdf http://virtual.clemson.edu/groups/psapublishing/PAGES/FYD/fydhmnt.htm page

Our solution: we had Temp-Vents installed (the company ships anywhere and their prices http://www.ventking.com/ better) and our house is more beautiful too. They open and close automatically with the temperature differences. We were told by many that you close your vents manually. Who wants to do that? It could be 30 degrees at night here, then 65 in the day during fall and spring. Temp-Vents open and close automatically and do not even use electricity or batteries - and they really do look nice. Good luck!

You may want to have a mold expert (try Servicemasters) see if there is already mold under there. If so, the ventilation is not sufficient to get rid of. I would try to drill at least two sides of the space so that you seem to pass through.

Ventilation should be sufficient, if the vents are the correct size depending on the amount of space for ventilation. Also make sure that there is no mold or other things up there, as aspestos or something. Make sure theres no water either by causing the mold.

I live in the South too. When I bought my house the previous owner put a dehumidifier in it and the society it has also put clear plastic on the ground and all the blocks on the foundation. It is very dry!

cut vents on all four walls and install the duct grilles or covers. Check your crawl regularly and if it is not enough (although it should) install a fan 100V learned from the crawl space with a timer. Not to be strong and do not need to run all the time. Simply vents should do so.

Here's a little advice from the EPA:

http://www.epa.gov/iaq/homes/hip-moistur ...

And some others:
http://www.housingzone.com/article/CA625 ...
http://www.askthebuilder.com/543-Crawl-S ...