Quality of old timber

[chuckey]

I have taken down the roof structure of a pigsty. The purlin I recovered is 17' X 8 1/2" X 3" which is what I need as a floor joist in my barn. The timber is a bit worm eaten - the top 1/4" has holes in it. Anyway to test it I propped it up on blocks, sat on the centre, and measured a deflection of about 1/8" when I sat on it (13 stones). I did a similar thing with one of the new C16 9" X 2" floor joists and it did not deflect the thickness of a pencil line (<1/32").

All the existing floor joists in the barn deflect a lot, and the ones I have removed to make room for the 9 " X 2"s have been cut up to show the wood worm is only in the top 1/4" or so.

Has any one any comments on why this should be so?, the barn is in Wensleydale, where presumebley the timber came from.
Frank

 

[biffvernon]

I'd use it with no worry.

 

[Moneypit]

Different species of timber perhaps?

 

[Penners]

Even different trees of the same species can behave differently.