# Cracking in cedar slabs



## rmckenz85 (Feb 6, 2013)

I have a bunch of ceder slab and i cut some up to make a bench and brought the pieces in the house to dry out i woke up today and they are cracked all over? Can anyone tell me why? Are the drying too fast?


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## rmckenz85 (Feb 6, 2013)

rmckenz85 said:


> I have a bunch of ceder slab and i cut some up to make a bench and brought the pieces in the house to dry out i woke up today and they are cracked all over? Can anyone tell me why? Are the drying too fast?


It is eastern red cedar the slabs are 2 inches thick 12 to 14 diameter and 8-10 ft long the long were sitting at the mill for a month or 2 and i had them slabbed about 2 wks ago and they are sitting in my garage and its winter here so the temp is only around 30 deg and up. How long do i need to let them airdry before i can build furniture with them?


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## Shop Dad (May 3, 2011)

Your house has a very low ambient moisture level, especially in winter. The drying needs to be controlled so that the outside does not dry too much faster than the inside. They should probably be outside several months before bringing in, maybe more. Figure it dries approximately 1 inch of thickness per year outside.


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## rmckenz85 (Feb 6, 2013)

Ok. I thought cedar dried much faster than harwoods. Alot of people say they build with it in a few weeks and say its ok and others wait a few years. Not sure who to believe haha!


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## Shop Dad (May 3, 2011)

Cedar very likely does dry faster. Just not THAT fast.


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## TomC (Oct 27, 2008)

Shop Dad said:


> Cedar very likely does dry faster. Just not THAT fast.


Here in NC 4/4 ERC will be ready in about 6 week just air drying.
Tom


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## Shop Dad (May 3, 2011)

Good to know. I have some ERC courtesy of Sandy. Mostly for bowls though. So 8/4 needs 12 weeks?


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## scsmith42 (Jan 24, 2011)

Shop Dad said:


> Good to know. I have some ERC courtesy of Sandy. Mostly for bowls though. So 8/4 needs 12 weeks?


No.

For each additional inch, figure a 60% reduction on the drying rate. Thus, 8/4 dries at 40% of the rate of 4/4, and 12/4 dries at the rate of 40% of 8/4.


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## scsmith42 (Jan 24, 2011)

rmckenz85 said:


> I have a bunch of ceder slab and i cut some up to make a bench and brought the pieces in the house to dry out i woke up today and they are cracked all over? Can anyone tell me why? Are the drying too fast?


As others have indicated, your slabs are drying too quickly on the surface. The cracking that you mention is called surface checking.

It's best to air dry outdoors, under cover, preferably starting thick slabs in early winter when they will dry slowly for the first 6 months.

Wood dries very slowly - and poorly in log form. This too can create cracking due to the inconsistent moisture content across the slab.

Your best bet would be to move them back outside, and leave them for about 2 two 3 months (this advice only applies to a fast drying species such as cedar). You can bring them back into the house then for faster drying.


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## rmckenz85 (Feb 6, 2013)

scsmith42 said:


> As others have indicated, your slabs are drying too quickly on the surface. The cracking that you mention is called surface checking.
> 
> It's best to air dry outdoors, under cover, preferably starting thick slabs in early winter when they will dry slowly for the first 6 months.
> 
> ...


Im going to buy a moistue mete what % does it need to be to build with?


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## scsmith42 (Jan 24, 2011)

Edited to remove duplicate post.


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## scsmith42 (Jan 24, 2011)

If the bench is to be used indoors in a modern, climate controlled home, usually it will equalize out to around 7% inside the home. Thus, it's a good idea for the lumber to be 10% or less when you construct the bench, in order to avoid significant wood movement.

If the bench is to be used outdoors, then depending upon where you live (as well as the time of year) it will typically equalize out to somewhere between 12% - 16%MC.

If you buy a pin type meter, see if you can get one with insulated pins that are at least 3/4" long. That way you can reach the center of your 2" slabs. If you buy a pinless meter, see if you can buy one that will read to a depth of at least 7/8".

Wood dries from the shell to the core, so it's possible for the shell to be 12% while the core is still 30% or more. When you dry lumber your own lumber, you can make more informed decisions as to when to use it if you can read the MC% at both the shell and the core.


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