A 14k trailer and you never go with more than 8 yards? Or am I misunderstanding you and you have 2 axles rated at a total of 7k? I would think it's probably closer to 7' wide, I don't think even semi trailers are a full 8' wide. Even at that, I'm thinking you probably have a total rating of 14k....
FWIW, we have a 6'x14 trailer (total rated capacity is 7k) that we can stuff 10+ yards onto, as well as a 7x18 trailer (total rated capacity is 12k) that we can stuff 15+ yards onto.....
You have to watch your
combined gross vehicular wieght rating when buying a trailer. Any combination with a rating of 26,001 pounds or more, with a trailer rated at 10,001 pounds or more, you MUST have a Class A CDL. The CGVWR can be 26,001 pounds or more if the trailer is rated at 10,000 pounds or less. Until the truck rating is 26,001 pounds or more, then you are back to needing a CDL...
So basically if you have an F450 and a 12k trailer, you need a CDL. You should be fine (AFAIK) with an F350 and a 14k trailer, but you can't get any bigger with either one.
Dan