"Rich S." wrote in message ...

The wood you find at the Borg* may have the word "Fir" but you will notice
the absence of the modifier "Douglas".

Much to my surprise about six months ago in Pasadena CA or therabouts
I found some bords at the borg (aka Home Depot) that were stamped
by HD 'Green Fir' and 'Doug Fir' in another place by the supplier.
They were in fact green Douglas Fir.

It just goes to show you that it isn;t only the guys working retail
at HD who don;t know wood.

Douglas Fir is not fir. It is not even the same genus as fir. It
more closely resembles Larch and can be grouped by the American Software
Lumber Association with Larch in terms of properties but it isn't a
Larch either. Doug Fir is its own genus.

Anyhow, for structural lumber the common species groups in ascending
order by tensile strength are SPF (spruce or pine or fir) Hem-Fir
(Hemlock or Fir), Doug Fir or Larch, and Southern Yellow Pine.

Doug Fir and Southern Yellow Pine are about equal in strength and
stiffness, SYP is denser.


I'm about the open up a wall in my
living room and install a couple more windows. You can bet I'll be going to
a real lumber yard and buying kiln-dried Douglas Fir studs and headers. That
wet sub-species crap at the Borg will twist and turn like a stick of red
licorice as it cures.


Doug Fir supposedly has the unique property of maintaining dimensional
stability as it dries. I suspect that property was observed in the
Old growth wood and question if it it is still true for the plantation
grown stuff.

If I build an aircraft, you can be damn sure that I'll be getting my
wood from a bona-fide lumber dealer or direct from a sawyer and not
from a home center.

--


FF