Crawl space utilized: Storing Lumber

[Tim Allaire]

Underneath my house I have a 3ft crawl space that is empty. Any recommendations for storing drying lumber under there? It is a dry space (not that easy to access, but would work) and sheltered from the elements. Any moisture issues that anybody could think of?

Tim

[Jim Becker]

Not ideal because of limited air flow and likely damp conditions even if it's typically "dry". Nature of crawl spaces. How it was constructed will be a factor, too. Crawl spaces are also a natural draw for "critters" in many places.

[George Bregar]

I'm with Jim, there is no such thing as a dry crawlspace.

[Daniel McCurdy]

Every home is differnt, so I don't clame to know what your space is like, but I'd say yes, issues if you don't control the humidity. Maybe not too moist now, but what will it be like in a couple of months, especially in NC? I'd toss a hygrometer in there to see what the humidity level is...but better bet on it being different come spring and summer.

Airflow is the big factor in drying lumber. So you're going to have to make sure air is passing over that lumber (since the wind won't be doing it for you in there)...and then you'll have to get that air vented to the outside well enough so there's not too much moisture build up.

I'd probably pass on that one if it were my crawl space. But that's because it was easier for me to dedicate space outside for drying and get it covered from the elements. Plus I wouldn't want to lug weights around in that tiny space to stack on the pile. By all means though, if you can keep the moisture levels down and keep air flowing, I don't see why it would be an issue...except maybe the potential for bugs. But that wasn't your question.:)

Let us know what you decide.

[Keith Beck]

Tim,

I don't know if your part of NC is anything like it is here in southern Virginia, but there's no way I'd put any lumber in my crawlspace with the termite problem we have around here. I've already had to repair several termite infested areas in my house and I wouldn't want to give them any reason to keep hanging around.

My .02...

Keith

[David Giles]

While I agree that a crawlspace is less than optimal for wood drying, you kind of asked how to make it work. So here's some ideas:

1. Clean out any construction trash, such as old wood, nails and concrete pieces. Throw 1-2" of sand or fill dirt inside if the ground is clay. Line the dirt with 6 mil crosslinked plastic (the crosslinked stuff is super tough). Use "Great Stuff" canned foam to seal the plastic to the foundation. This eliminates any moisture from ground.

2. Spray the underside of the crawl space with Timbor using a garden sprayer. Timbor resists mold and mildew and will protect the underfloor from higher moisture content. It also stops roaches and termites.

3. Set up a ventilation system to circulate air around the boards and out of the crawlspace. Use a moisture sensor to monitor relative humidity. Add a couple of lights to see.

4. Add an inexpensive source of heat if you can. I'm thinking of solar panels circulating hot water. Open flames are probably a bad idea.

5. Rig up a way to move around the crawlspace. Maybe lay 3/4" ply over the plastic and use an mechanics creeper to roll around.

If you do this, please post some pictures. It would be a wood drying first!

[Chase Gregory]

Don't let the folks that hold your termite bond see the buffet...;)

Chaser

[Steve Clardy]

Your attic space [if you have one] would be a better choice.

[David G Baker]

If the crawl space was located in a state that has warm temperature and low humidity like areas of California and the South West it may work. The house I had in Northern California was required by code to have good cross ventilation in the crawl space. I did a lot of work in the crawl space year round and it was always dry. If the lumber could be stored suspended from the floor joists and had no ground contact, it might work.

[Chris Padilla]

Yep, what David said. My crawl space here in the Bay Area is as dry as the Mohave and if I thought about it, I could possibly store wood under there but it would take some work to make access easy...so I won't do it. :)

[Joe Chritz]

I have been doing some research on air drying lumber and David's post #3 and #4 are the most important from what I understand. It is less important where the lumber is and more important what the conditions are. That's why solar kilns and the like can work.

Steve Clardy's idea of attic storage is best. I use an overhead rack that will store about 100-150 BF but if I would have though of it I would have made attic storage by using trusses designed for the task. Especially since I just sourced a lot of air dried cherry for $1.85 BF. :D

Joe

[Tim Allaire]

Does anyone have a lead on a solar powered heater that would work for such a task? Perhaps something that would move air? Wouldnt that help with the moisture content (along with the a sand bed and proper weight--thinking about using a car jack to apply pressure rather than weights). Suggestions?

[John Schreiber]

That's an interesting idea which would work for me too. I imagine making some kind of a rack which would keep it away from the existing floor walls and ceiling, perhaps hung from the joists. Perhaps some sort of a semi-enclosed box with a low power electric heater at the bottom. I think I may experiment with a relative humidity indicator down there to see what happens.

[Jim Becker]

Tim you need air movement, not heat. The best place to dry lumber is outdoors where the wind can blow through the pile and wick of the moisture being released. My concern with an attic is that it may get too hot too fast and that can cause other stability issues with the lumber.

[Sam Yerardi]

I agree a bit with Jim on the reservations of using the attic because depending on the attic, the ambient temperature can go up and down dramatically on a regular basis which may/may not be good for the lumber. Having said that, I once bought a stack of cherry that had been in the attic of a barn for many years and it was very dry and stable. Granted, I can't say that was an apples to apples comparison (actually a cherry to cherry comparison - sorry I've needed a laugh all day - couldn't resist it :).

[Bob Feeser]

Here is a little humor.

http://img.photobucket.com/albums/v196/evsac/Video/useless.gif

Besides that, pertaining to curing. I had some 2" thick walnut, fresh, and raw from the sawyer, that were the whole width of the tree/coffee table top style with bark in both sides, placed them in a hot attic for a summer, and they were cooked. No problems. For thinner stock you need stacks, with separator sticks in between, so the weight of the stack keeps them straight while they are drying. Professional kilns use that method. The longer you take to cure wood, the more stable it is. Force dried/kiln is less stable than stacked cured over a summer in a warm garage, and basement cured in an aerated basement, that is cooler over 2 years is even better. Then again, kiln dried wood that is able to sit for a while is a good idea. I know Hearnes Hardwoods advertises that they kiln dry it, then store it for a year. (Jim are you listening, I know Hearnes is one of your favorites;-)
Another sawyer that I use, when asked if there is any other special instructions, he says, "Yeah, keep it out of the sunlight".
Pertaining to using the crawl space; Is the air circulated with a fan constantly, and is the ground under it moist, or are you in a higher elevation, with a water table that is deep underground. In a moist environment, which crawl spaces are famous for, since many of them are that way because a basement can not be dug because of the perc, then trying to aearate that space reliably is a challenge. If it is especially dry underneath it, and ventilated with a fan, that could be ideal. An outside storage shed is better, and I have seen rural areas with a wood stack, simply covered with a tarp to keep the rain off of it, and the sun off of it, but allow the air to get through. Stacked once again with spacers. By the way do not scrimp on how wide the spacers are, it really makes a difference. I had some 1/2" spacers in a garage, and it wound up mildewing. There was only an inch of space in between the stacks as well.

[Steve Clardy]

I agree a bit with Jim on the reservations of using the attic because depending on the attic, the ambient temperature can go up and down dramatically on a regular basis which may/may not be good for the lumber. Having said that, I once bought a stack of cherry that had been in the attic of a barn for many years and it was very dry and stable. Granted, I can't say that was an apples to apples comparison (actually a cherry to cherry comparison - sorry I've needed a laugh all day - couldn't resist it :).


Same basis as a solar kiln.

Heat during the day, cooling off period at night.

I've done it both ways. Attic and solar drying.
Never noticed any difference.