Possible movement in slab after resawing

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Forum topic by ThePoulsen83 posted 11-06-2018 04:51 PM 500 views 0 times favorited 6 replies Add to Favorites Watch
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10 posts in 619 days

11-06-2018 04:51 PM

Topic tags/keywords: wood movement resaw elm

Hi All

I’m currently looking into purchasing a couple of elm slabs that a guy near me have had in his attic for the last 20 or so years. (So it should be bone dry)

The slabs are a little over 2” thick.

If I decide to buy the slabs, I’d like to extend the use of them a bit (They are quite expensive here in Denmark). I am therefore considering if I could take the slabs over to a local lumber mill and have them resaw the slabs into app. 1” thick slabs.

My concern however is on how the wood might move following such an operation. and how should I procede in order to avoid the worst movement?

Would it be ok if I put them into my house with sticks between them, and some weight on top?


6 replies so far

View AlaskaGuy's profile


5522 posts in 2917 days

#1 posted 11-06-2018 05:10 PM

Wood does not dry do to age. The woods moisture content will in equilibrium to where it is stored. If the attic had high humidly the wood will have a higher MC than if it was stored in a low humidly attic. Wood will adjust to its environment regardless of its age.

-- Alaskan's for Global warming!

View pottz's profile


7700 posts in 1592 days

#2 posted 11-06-2018 05:25 PM

A G is right you need to check those with a moisture meter if the moisture content is high and you resaw them they could very well attic is usually not very climate controlled.

-- sawdust the bigger the pile the bigger my smile-larry,so cal.

View Robert's profile


3602 posts in 2088 days

#3 posted 11-06-2018 05:31 PM

The key word is “acclimate”. For example where I live fully acclimated air dried lumber is 10 – 12%.

I always move lumber inside to climate controlled room to get down to 8%. So I agree about moving the boards inside.

Regardless, when the wood is opened up by sawing any internal tensions in the wood will be released.

Granted air dried wood is less subject, but unfortunately you won’t know until you saw it.

I suggest sticker the boards immediately after sawing and use some type of clamping or band straps to keep the wood flat. I think this works much better than weight alone.

-- Everything is a prototype thats why its one of a kind!!

View Aj2's profile


2650 posts in 2405 days

#4 posted 11-06-2018 06:02 PM

Trying to net to usable slabs from one that been sawn thick is not a very good idea. But then it really depends on what they look like some will call branch wood slabs or just planks that have bark on both sides slabs.
If I wanted to net 1 inch fo4 a project I would start with 5/4. And sneak up to my final thickness

Not saying it cannot be done but it’s a lot of extra work if the wood is wide and unruly.

Good luck

-- Aj

View msinc's profile


567 posts in 1111 days

#5 posted 11-06-2018 06:05 PM

Unless the ambient temperature of the area of that attic is pretty low I seriously doubt there will be any “high” moisture content. High humidity and attics are generally pretty rare. That said, the problem still may be worse going the other way. If the wood is as suspected and extremely very dry {low MC} and you saw them and change the location to an area with some humidity {I could hardly see how you could not, given you’re taking them from an attic to anywhere else besides an oven!!} then it is going to move.
Movement doesn’t just occur when going there is a decrease in moisture content…it also moves when going from very dry an increase in MC. In fact, I have to say, based on my experience that wood sometimes can move more when picking up moisture. Still, 20 plus years in an attic is along time to dry out…I wouldn’t look for too much movement as long as the new location is relatively dry. Best of luck.

View Manitario's profile


2797 posts in 3490 days

#6 posted 11-06-2018 06:32 PM

The wood will likely move due to two different issues; one is change in moisture content between where the wood was stored and your home/shop. The best way to deal with this would be to leave it for at least several months in your house before you try and re-saw it. Clamps/weight etc. may help keep it flat as the sawn pieces adjust to the moisture content of your place.

The second issue is internal stresses in the slab, is harder to predict and deal with. The slab may twist, cup etc when re-sawn, and no amount of clamps, weight, straps etc. is going to help, the wood will just go back to where it wants to go when you let the weight, clamps off.

My experience with slabs and re-sawing in general is plan for the movement, ie. if you have a 2” thick slab, don’t plan on getting two usable 1” thick pieces out when you re-saw it. Eg. I had some beautiful 8/4 claro walnut slabs that were well seasoned and acclimatized. One slab I got almost 1” thick resawn boards from, the other just kept cupping and twisting and the thickness of the usable pieces from it was only ~1/2”.

-- Sometimes the creative process requires foul language. -- Charles Neil

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