DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Building & Construction (http://www.diychatroom.com/f19/)
-   -   crawl space and moisture (http://www.diychatroom.com/f19/crawl-space-moisture-32684/)

Jeremy Hillary Boob, PhD 11-26-2008 07:33 PM

crawl space and moisture
 
I have a narrow crawl space under part of my house---it varies from about 24 inches below the floor, to just a few inches. When we moved in (about a year ago), it was a rats paradise, so I spent a lot of time sealing up the entry points. It wasn't exactly ventilated before, but there were some fairly easy entry routes for those nasty beasts (which may have provided some limited ventilation, but also allowed some water in). In any case, no rodents are getting into that crawl space now, but I'm thinking that moisture is going to create problems (i.e., dry rot). I have a couple of questions.

1) Is it critical to ventilate the crawl space? I live in a damp area (a redwood forest, with lots of rain and fog during the winter), so it's not going to be extremely dry, even with good ventilation.

2) Assuming the answer to 1) is "yes", do you have any suggestions on how to go about this? There is no easy access to the crawl space and I don't want to give the rodents any way in, so the fewer potential access points I create, the better.

Thanks.

4just1don 11-26-2008 08:42 PM

Have you considered a dehumifier that dumps either into a drain OR pumps outside?? that way NO outside humid air is going inside,just drying it out,,,which it needs anyway. Put it on a medium setting and it runs when it needs to.

Do you heat the house in winter time?? Just a furnace duct run down there will help,,with the dry furnace air. Same with a little ac air.

joasis 11-26-2008 09:05 PM

1 Attachment(s)
This is what will happen if you seal a damp crawl space, and this is a picture from a home in Oklahoma...semi arid climate.

4just1don 11-27-2008 07:44 AM

Another crawl space trick is to put 6 mill poly or better,,down on the ground,,,keeps most of the musty smell and most of the humidity in the ground. A little bit of that playbox white sand they sell at big box stores around the edge,,to keep it down,,and your good to go.(or rob your kids or neighbors sand box) Smooth rocks work too

Jeremy Hillary Boob, PhD 11-27-2008 02:51 PM

Quote:

Originally Posted by 4just1don (Post 190627)
Have you considered a dehumifier that dumps either into a drain OR pumps outside?? that way NO outside humid air is going inside,just drying it out,,,which it needs anyway. Put it on a medium setting and it runs when it needs to.

Do you heat the house in winter time?? Just a furnace duct run down there will help,,with the dry furnace air. Same with a little ac air.

Quote:

Originally Posted by joasis (Post 190635)
This is what will happen if you seal a damp crawl space, and this is a picture from a home in Oklahoma...semi arid climate.

Quote:

Originally Posted by 4just1don (Post 190710)
Another crawl space trick is to put 6 mill poly or better,,down on the ground,,,keeps most of the musty smell and most of the humidity in the ground. A little bit of that playbox white sand they sell at big box stores around the edge,,to keep it down,,and your good to go.(or rob your kids or neighbors sand box) Smooth rocks work too

Thanks for the suggestions. There is no way I can get sufficient access to put down a poly sheet over the dirt---I'd be lucky to cover 25% of it. The house is heated by a pellet stove and there is no AC. I think the dehumidifier might be the only realistic option but even that will not be easy to rig. I might have to cut a hole thru the subfloor, which should be interesting.

Btw, I removed a big chunk of the subfloor (about 5' x 9') when I remodeled a bathroom (I only removed it because rats had damaged part of it). In the process, I found a small patch of dry rot, but I was actually surprised there wasn't more, given that the house is 20 years old (and I'm sure the crawl space was essentially sealed for most of that time).

joasis 11-27-2008 08:13 PM

If you do not get some kind of ventilation going, the small area of dry rot you exposed in a 20 year old home will eventually consume the entire sub structure of the home...and a dehumidifier isn't cheap to run in the long haul....you might wish to call a building inspector for on site advice.


All times are GMT -5. The time now is 05:12 PM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved