Posted: 16/09/2014 at 23:40
If it is sold as 10ft x8ft it has to be that size regardless of the preservative. You have the right to reject the goods as they are not as described and as such not what you were paying for. That's the basis to reject them, the lack of preservative on the inside doesn't really matter that much in law, it just adds to the evidence that the product you bought was not what was supplied. Was it advertised as treated as well, if so that hasn't been done properly so the company that supplied it hasn't got a leg to stand on in law. If you do decide to take it further, photographic evidence to back your claim, both of your shed, and the display models will assist the case.
As for the aggravation, well that's up to you.