How long for wood to dry?

[djay]

How long can I expect green 4X4 and 2X4 lumber to cure? I have it all stacked together on a level surface. I do not have 1/4" strips separating the wood, however there is a constant dry breeze. Am I looking at 6-8 weeks? 6 months? I know there are variables that I haven't thought of, but I'm just trying to figure out when I can use this stuff. Also if this lumber is on a level surface, can I expect it to warp? How can I prevent warp?

Thanks,

Djay

 

[Doug Miller]

How long can I expect green 4X4 and 2X4 lumber to cure? I have it all stacked together on a level surface. I do not have 1/4" strips separating the wood, however there is a constant dry breeze. Am I looking at 6-8 weeks? 6 months? I know there are variables that I haven't thought of, but I'm just trying to figure out when I can use this stuff.

Without strips (called "stickers") separating the layers of wood, it will not dry in your lifetime - it will rot first. The wood *must* have air circulation on *all* sides in order to dry. And the stickers need to be thicker than 1/4" for proper air circulation: 3/4" is better.

You *must* sticker the wood if you expect it dry properly. This is not optional. You'll have a pile of useless, rotted wood within a year if you don't.

The rule of thumb for air-dryed wood is one year per inch of thickness, plus one year - so figure 5 years for 4" thick lumber, 3 years for 2" thickness. If you live in an area with very low humidity (such as Arizona), it won't take that long; OTOH, if you're in Florida, it could be much longer.

Also if this lumber is on a level surface, can I expect it to warp? How can I prevent warp?

Not enough information to tell. Depends on the species, on the individual tree, what part of the tree the wood came from (trunk or branch), on how the wood was sawn from the log, and on how it's stacked.

If the tree was pretty close to straight when it was alive, the wood came from the trunk and was cut properly and stickered promptly, stacked on a level surface, you won't see too much warping. OTOH, if the tree was leaning, or if you cut lumber out of large branches, it'll warp. (Google search on "reaction wood" to learn why.) Some species (e.g. beech) are prone to warping, others (e.g. black walnut) generally are not. Quartersawn lumber is more stable than flatsawn lumber. And on and on.

For more information:

1) look for a copy of "Fine Woodworking on Wood and How to Dry It" at your local library

2) check out the chapter on drying wood in "Wood Handbook: Wood as an Engineering Material" available on-line at http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm

3) post your question over at rec.woodworking - several guys there air-dry their own wood, and can give you a lot of useful tips.

 

[djay]

Without strips (called "stickers") separating the layers of wood, it will not dry in your lifetime - it will rot first. The wood *must* have air circulation on *all* sides in order to dry. And the stickers need to be thicker than 1/4" for proper air circulation: 3/4" is better.

You *must* sticker the wood if you expect it dry properly. This is not optional. You'll have a pile of useless, rotted wood within a year if you don't.

The rule of thumb for air-dryed wood is one year per inch of thickness, plus one year - so figure 5 years for 4" thick lumber, 3 years for 2" thickness. If you live in an area with very low humidity (such as Arizona), it won't take that long; OTOH, if you're in Florida, it could be much longer.

Not enough information to tell. Depends on the species, on the individual tree, what part of the tree the wood came from (trunk or branch), on how the wood was sawn from the log, and on how it's stacked.

If the tree was pretty close to straight when it was alive, the wood came from the trunk and was cut properly and stickered promptly, stacked on a level surface, you won't see too much warping. OTOH, if the tree was leaning, or if you cut lumber out of large branches, it'll warp. (Google search on "reaction wood" to learn why.) Some species (e.g. beech) are prone to warping, others (e.g. black walnut) generally are not. Quartersawn lumber is more stable than flatsawn lumber. And on and on.

For more information:

1) look for a copy of "Fine Woodworking on Wood and How to Dry It" at your local library

2) check out the chapter on drying wood in "Wood Handbook: Wood as an Engineering Material" available on-line at http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr113/fplgtr113.htm

3) post your question over at rec.woodworking - several guys there air-dry their own wood, and can give you a lot of useful tips.

Awesome post Doug. I appreciate all the great information!

Djay

 

[TURTLE]

How long can I expect green 4X4 and 2X4 lumber to cure? I have it all stacked together on a level surface. I do not have 1/4" strips separating the wood, however there is a constant dry breeze. Am I looking at 6-8 weeks? 6 months? I know there are variables that I haven't thought of, but I'm just trying to figure out when I can use this stuff. Also if this lumber is on a level surface, can I expect it to warp? How can I prevent warp?

Thanks,

Djay

This is Turtle.

Without Strips deviding the wood to dry. It should be dry by the year 2035 or maybe 2040.

If you strip it ever 30 inches you should not have much warping of the wood. Like it is you can see the dry wood by it turning up or bowing up to show it. As it drys through the years it will bow to tell you it is dry.

Doug Miller has some good words on dring the wood.

TURTLE

 

[PrecisionMachinisT]

How long can I expect green 4X4 and 2X4 lumber to cure? I have it all stacked together on a level surface. I do not have 1/4" strips separating the wood, however there is a constant dry breeze. Am I looking at 6-8 weeks? 6 months? I know there are variables that I haven't thought of, but I'm just trying to figure out when I can use this stuff. Also if this lumber is on a level surface, can I expect it to warp? How can I prevent warp?

As others have already said, use stickers....get it up off the floor first.

Also, consider banding the entire bundle together with steel strapping---as this will prevent almost all warpage.

 

[Guest]

The rule of thumb for air-dryed wood is one year per inch of thickness, plus one year - so figure 5 years for 4" thick lumber, 3 years for 2" thickness...

I wonder how that changes for a low-temp kiln, eg a pile of stickered wood in a greenhouse.

Nick

 

[barry (archive)]

Or, weight it down with cement blocks over the stickers.

Other factors of importance:

1. cover the stack, like with tarp, over the top, and extending off the sides, to shed water and minimize direct sunshine. Cover as little as possible.

2. place stack with max southern exposure, and open to wind movement. Temperature is very important to drying wood, having major impact on equilibrium content of wood and drying rate.

HTH,
John

 

[ConcreteFinishing StuccoGuy]

The important thing to remember in home drying rough wood is keep it slow. The slower the drying the less checking and fibre seperation. If the wood is to be used for framing, use it green and quick or it will walk away on you. Old timers up here in central ontario's logging country would stack and sticker hardwood in barn lofts and cover it with sawdust to control drying. Quick dries destroy wood.