Clear Plastic over wood pile to dry faster ?

[SmokeyCity]

I got an idea from bogeydave's posts that I'm gonna test on my woodpiles. I have some 4 mil clear plastic 10'x 25' sheets.

If I completely cover my piles with this plastic I should get a greenhouse effect on hot sunny days that will draw out moisture onto the under sice of the plastic. I can then flip the plastic every week to restart the cycle.

Anybody ever do this already ?

 

[midwestcoast]

I would definitely not cover the piles completely with it. The moisture that condenses on the plastic does so because it was blocked from escaping as a vapor. Adequate venting on top for exhausting hot moist air & intake on bottom for fresh air and you MIGHT see a benefit over a fully open stack. You need to ensure good airflow to replace the wind that you're blocking with the plastic. Should probably post in the Woodshed

 

[oldspark]

Yea you need air movement to go with the heat so completely covering the piles would not be good.

 

[Jags]

Its gonna turn into a mold factory and turn your wood into junk. Leave it uncovered until it gets close to the burn season, then cover the TOPS only, allowing air to hit the sides.

 

[woodsmaster]

I cover my single rows with black plastic or rubber roofing top only, to draw the heat and keep rain out of the middle of the stack.

 

[Jags]

maybe if u had pallets bewteen the pile & the plastic?

Nope - gotta have an air exchange to get rid of the moisture. Its like sealing up a zip top bag.

 

[daveswoodhauler]

Having used the tent method the op speaks of, I would urge you not to use the greenhouse application as your wodd will not season.
Take it from one that larned the hard way....as others have posted, you need air flow....cover the tops only during winter if you need to.

 

[Dieselhead]

why is it frowned upon to cover just the top of the pile during the summer months? I figure the more rain you can keep off it the faster it would season. no?

 

[Jags]

why is it frowned upon to cover just the top of the pile during the summer months?

I don't think it is frowned upon. Your local weather may play a part in that too. But one thing is for sure, no matter where your at, keep the sides open.

 

[Adios Pantalones]

Covering just the top- may or may not help. Covering the whole thing to create a solar dryer with a chimney effect wit table service, etc- has been found to not help.

I would like to test a passive system with a big black sheet metal inlet to preheat the air- increases heat and air flow. Just fer fun. You know- with all the spare time I have

 

[SteveKG]

Covering the top is ok. I built permanent sheds for five cords, the long sides are both completely open, the ends are solid and the roof is galvanized barn roofing sheets. The ends and floor actually do have some small spaces between the planks. In any case, it works great and the wood seasons quickly.

 

[budman]

Might as well have the wood chucks, chuck your wood in the lake. :ahhh:

 

[Backwoods Savage]

why is it frowned upon to cover just the top of the pile during the summer months? I figure the more rain you can keep off it the faster it would season. no?

The idea is to get the moisture to evaporate. Covering the top of the wood can impede this. However, in very wet climates, they do need to keep the stacks covered. Around here we cut during winter, split in the spring and stack the wood immediately. We leave the wood uncovered until late fall or early winter; before the snow flies. Then we cover the top of the stacks. Only the top.

To give you an idea of what happens, we stack our wood 4.5' high. By fall, that 4.5' has become 4' or less. That is because of the moisture evaporating and, of course, the wood shrinks a bit.

 

[Danno77]

this is wood shed material, no?

 

[Wade A.]

What is being proposed is something akin to a passive solar wood drying kiln....and those can be very efficient....but, you've got to provide ventilation for the warm, moist air to escape. Otherwise, as has been noted, it will merely condense when it cools and rot and mold will result. If you really wanted to take this to the next level, you can build a frame, drape it with clear plastic and hook an a/c fan, or (better yet) a d/c solar fan up to a PV panel, and run either one to an exhaust port. OTOH, I'd go to this trouble only if I were drying hardwood for furniture or cabinetry, and dare I say that this seems a pretty extreme measure to take for preparing wood to burn. Better off putting the time, money and effort into locating wood to buck, split and stack to season in time for winter. Just me.

 

[remkel]

Its gonna turn into a mold factory and turn your wood into junk. Leave it uncovered until it gets close to the burn season, then cover the TOPS only, allowing air to hit the sides.

+1- keep those piles/stacks open to air. The greenhouse effect will also trap moisture in.....let the air and sun do their jobs

 

[snowleopard]

If you *had* to put something on top to keep the rain off, I'd consider corregated plastic panels made for greenhouse roofs. They're ridgid enough not to drape the wood, and the moisured might evaporate out of the ends.

Better yet, build an elevated roof with this on it, and open sides. Put the pallets underneat the wood. Good hat, good boots.

 

[CTYank]

why is it frowned upon to cover just the top of the pile during the summer months? I figure the more rain you can keep off it the faster it would season. no?

It is ABSOLUTELY NOT frowned upon, not by experts in the lumber-processing field, and for two reasons:
1) You do not want the lumber to crack/split/check from local temp extremes.
2) You do not want liquid water coming in contact with the wood. (Weren't you trying to remove water?)

2) applies here, to speed up air-drying.

"season" is vague and meaningless here; "dry" is the operative word.

 

[drozenski]

I covered mine in clear plastic last year and it worked out great but i wont do it again.

The wood dried much faster, I only pulled the plastic 1/3rd the way down the sides

i had a temp sensor in the middle of one of my stacks and it hit 148 degrees on some of the less windy days. Usually 125 on a good windy day.

Though summer + fall + winter / the elaments destroyed the plastic and it's no longer any good. $60 down the drain. So im building a wood shed.

 

[Backwoods Savage]

why is it frowned upon to cover just the top of the pile during the summer months? I figure the more rain you can keep off it the faster it would season. no?

It is ABSOLUTELY NOT frowned upon, not by experts in the lumber-processing field, and for two reasons:
1) You do not want the lumber to crack/split/check from local temp extremes.
2) You do not want liquid water coming in contact with the wood. (Weren't you trying to remove water?)

2) applies here, to speed up air-drying.

"season" is vague and meaningless here; "dry" is the operative word.

Indeed we are trying to remove water....but are not trying to make lumber nor are we kiln drying our firewood. We generally do not get our firewood as dry as the lumber you buy.

Unless it rains a lot, like maybe in the Pacific NW, water will just run off the logs and there is a huge difference in how lumber and firewood is stacked. We can get an inch or more of rain and the following day our wood will be dry. Wood is not a sponge unless it is punky, in which case I would not bother to cut it at all. We do not cover our wood in the first summer and fall but leave it open to better evaporate the moisture. Then we cover the top before the snow flies.

 

[Dieselhead]

why is it frowned upon to cover just the top of the pile during the summer months? I figure the more rain you can keep off it the faster it would season. no?

It is ABSOLUTELY NOT frowned upon, not by experts in the lumber-processing field, and for two reasons:
1) You do not want the lumber to crack/split/check from local temp extremes.
2) You do not want liquid water coming in contact with the wood. (Weren't you trying to remove water?)

2) applies here, to speed up air-drying.

"season" is vague and meaningless here; "dry" is the operative word.

good replies, I CSS and covered pile 4.5 cord 6 months ago. hope to be able to use it for 2011 season by keeping as much moisture off the pile as possible.

 

[billb3]

I have 1/3 cord of red oak on a rack drying with a plywood "roof" on the top. Just a couple splits holding the plywood from blowing away.
Another identical 1/3 rack right next to it with no cover.
The top four "rows" of splits in the uncovered rack are sometimes wet for days after a good rainstorm and are full of fungi. Dtuff on the bottom of the rack is nice and just like the coveredrack.
I'd rather use a piece of plywood to keep the stack dry than the top layers of an open stack.

It's just fungi, but that is part of a decomposition process I'd rather avoid.



If you don't get rain often and high humidity and your uncovered stack don't start growing weeds and maple trees like so many uncleaned gutters then you probably will get by without covers on top.
Most important is to have the wind help massage the moisture away.

Middle of an open field is usually best for that.
Barring having an open field most of us have to make do with a compromise that comes as close to that as possible.

 

[Wade A.]

Ditto to CTYank's comment. Most of the lumber I've used for furniture making (cherry and walnut) were cured/dried/seasoned in just this manner. We'd take the boards right out of my grandfather's sawmill and stack 'em up with spacers (stickers) between them. Whe the pile got too top heavy to safely put more on it, we'd top it with some sheet metal roofing or any other rigid, waterproof covering we had. The crucial point was to extend a drip edge a sufficient distance so that there was not chance of water running down the side of the stack. In a couple of years, your green lumber would stabilize to the point where you could plane it down to thickness, width and length.

 

[roddy]

gotta put my 2 cents in......i,m a lumber purchaser for a large wholesale op outta Ky(i run a Canadian division).....when we kiln dry lumber we take to 5 % then put back moisture to relieve stress that occurred the drying process,finishing about 6-8 % moisture (simply put) now when we finish the drying process,lumber is covered right away.one rain shower will drive the moisture up past 15 %.it is never let uncovered.people who say moisture wont find its way back into wood are just not informed(or choose not to be)sure ,it may be on the surface,but it takes time to dry out and return to the previous
level of dryness...thus you are extending your drying time each time your wood get s wet....its as simply as that,cover your wood,and leave space between your top row and the cover if possible....now your drying wood efficiently,oh yeah plastic does not make a good cover,any moisture must be allowed to dissipate...

rod

 

[Don2222]

Hello

My plastic is to keep the water and snow off the top. Air still comes thru the sides.