On Thu, 29 Dec 2005 21:18:58 -0800, Larry Jaques
wrote:

On Thu, 29 Dec 2005 15:52:23 -0500, with neither quill nor qualm, Greg
quickly quoth:


I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

I seem to recall seeing that being covered in "Understanding Wood" by
Bruce Hoadley. See your local Librarian!


You are correct on that. Table 6.2 gives the tangential/radial expansion
differences and there is discussion following that regarding estimating how
much a piece of wood at one moisture content will move when the humidity
causes the moisture content to change to another value. One could probably
do some worst-case analyses to find the limits using the formulae Hoadly
provides.



+--------------------------------------------------------------------------------+

If you're gonna be dumb, you better be tough

+--------------------------------------------------------------------------------+