How long can logs sit before sawing?

[Kbeitz]

The oldest down tree I have cut I think was down in the weeds not protected for around 7-8 years.
It was a 30" white pine. All the bark was gone and had some beetles holes but it was mostly good.

[Jeff]

The oldest log I ever sawed was on a circle mill. It was a 24" white oak. The old farmer was in the sawbooth  watching me, as he was a friend of the bosses, the ONLY reason we were sawing it.  The first cut you could actually see sparks, and there was no bark on this log. The saw got warm on that first cut.  I looked over my shoulder and asked him how long that log had been around.  He said, hmmm, let me see, I guess I put it in the barn in 19(dont remember now) but at the time it worked out it had been in the barn for 15 years, and had 15 years of barn residue on it.
The worst log I ever sawed.