Determining the species of Wood Beam
Determining the species of Wood Beam
(OP)
I am trying to determine the species of several timber beams reclaimed from an old barn. Of course I am trying to determine the structural properties, but beyond that I am just plain curious since some of the scrap may be used for furniture. Does anyone know where I can send samples to have them tested and also how much this sort of testing might run?
thanks,
~waytsh
thanks,
~waytsh





RE: Determining the species of Wood Beam
RE: Determining the species of Wood Beam
See http://www2.fpl.fs.fed.us/WoodID/idfact.html
for more info.
Good Luck!
RE: Determining the species of Wood Beam
RE: Determining the species of Wood Beam
RE: Determining the species of Wood Beam
For wood strength ASTM D143, D245, D1990, 2555, and D4761 are the appliable testing standards in the US.
ASTM D143 is one of two basic mechanical testing Standards for wood in North America when the goal is to develop estimates of properties for structural design. ASTM D143 tests small clear (knot- and defect-free) specimens then modifies the clearwood properties and their variability to estimate the 5th percentile of clearwood property then further account for the effects of knots, slope-of-grain, density, and grain orientation (flat-, quarter-, or bastard-sawn). With flat-sawn lumber the growth rings are parallel to widest face. With quarter-sawn lumber the growth rings are perpendicular to widest face. With bastard-sawn material there is NO control on growth ring orientation. Bastard sawn most accurately reflects actual production lumber. ASTM D245 instructs the user how to use D143 values to derive allowable design stress (ADS) values. ASTM D4761 is used when testing production-sized lumber and timber. ASTM D1990 instructs the user how to use D4761 values to derive ADS values. Both methods are used to derive allowable design stress values in North America. Most hardwoods use the D143/D245 methods, most softwoods use the D4761/D1990 method. The former was used from 1934-1990, while the latter is now the preferred way.
Consider a 3-point flexural test method.
see the proceedures listed at:
http
http
and additional info at
http://www.wwpa.org/_techguide/subscribe.asp see TN4 and TN5
Cheers
Boo1
RE: Determining the species of Wood Beam
Note also that published allowable stresses for some species have changed over the years, because testing methods have evolved, and also (I've been told) because recently grown versions of some species simply don't have the strength their old-growth incarnations had. (Why that is might be another good topic for this forum.) When looking at a very old wood structure it may be advisable to at least start with a review of any design data that you can find for your wood species that is contemporary with the building. Hope this helps. Good luck.