wood, timber, lumber

[popndekl]

what is the difference?

[gorbee natcase]

Timber is cut and stress graded

[mikeyg]

timber is what you yell when a tree is aout to fall down.

[Floristan]

Wood is the generic category: timber is wood, lumber is wood.  Timber refers to trees that will be or have been cut for processing into lumber.  Lumber is processed timber.

IMO     (I can't believe I'm answering this!  )

[Torp]

Here is my take:

Lumber is a type of finished good (like plywood is another type), you find it in Home Depot.  

Wood is a term that is commonly used to refer to the intermediary raw material before it is turned into lumber or plywood but after some burly logger cuts it down.  You'll find this out in the log yard or on a log truck.

Wood is also a term used by those not in "the know" to describe anything from a tree on the stump to the Home Depot inventory.

Timber is essentially the raw resource, i.e. a tree with branches, standing on the stump, you find it in the forest.  

It should be noted that most of these terms are interchangeable in many cases.  Timber is a case in point.  As mentioned, timber can refer to the actual trees in a forest, but, it can also refer to a finished piece of wood used in timber framing.  You see this type of construction in ski lodges sometimes.

Why do I know such things?  I work here...

www.bc.com

[popndekl]

well... thanks 

[Torp]

Well...you're welcome.