checks from developing in air drying.
Perhaps you have noticed that the past
few summers in the U.S. have been accompanied by unusual, extremely dry
air for a week or so.
In Georgia, we have seen humidi-ties under 30 percent RH in the warm
afternoons…dry enough to check
freshly stacked oak even with excellent
When lumber is dried to 7 percent
MC, but then is exposed to more
humid air in shipment or storage ( 65
percent RH is a common average RH
in much of the U.S.), this will swell the
surface slightly and close the checks so
tightly that they cannot be seen. Exposure to the dry air in a heated plant,
home or office will reopen them as the
A varnish or other finish will not
stop moisture movement enough to
prevent this from happening. The best
that you can do, in addition to working
to improve air drying, is to cut surface
check samples from wide, flatsawn
See page 102 in Drying Hardwood
Lumber ( https://www.fs.usda.gov/
treesearch/pubs/5710) for instructions
on how to cut these test pieces.
QWe have some jatoba piec- es and they seem to have a lot of splits developing
after we finish the pieces...
like a month later when installed in
a home. We checked the MC on the
returned pieces and it checked ok.
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“Higher lumber prices mean that the yield of
parts for lumber will be extremely critical for a