most timber yards simply won't know what you are talking about. They keep their stock out of the actual rain but that's about it for weather protection.
Depends on the yard.
Dedicated timber suppliers tend to know the worth of their stock if its to be used for joinery and sold as unsorted as they will have too many returns if it isn't stable. The place I used to go to in Bristol before they were swallowed up by Travis Perkins had a dedicated racked shed for this purpose, with the timber kept well away from any weathering. I've usd their timber for years without any problems.
The builders merchant types may not be so diligent though, and this is evident when you actually ask for unsorted. The majority seem to think that as its stacked in piles of random lengths, it is indeed 'unsorted!' :shock:
That said, how many hardwood importers keep their stock in climate controlled conditions once it's off the ship?
The ones I've known around Bristol, (and there were quite a few when the docks were working) all had similar set ups, slatted storage barns for air flow, and a tin roof to keep the water off.
Andy