While spending the Winter in Alabama last year I did a roof and caulk inspection.
I noticed the vinyl screw cover the length of the roof on both sides was cracked for almost the entire length of the trailer.
I contacted Heartland Customer Service and explained my problem.
I was told that Heartland had discovered that on early models of the 3450TS the vinyl screw cover did not have the correct amount of UV inhibitor in the product, causing it to crack.
Heartland sent me enough vinyl screw cover to replace both sides of the roof, at no charge to me.
Always check with Heartland Customer Service before you buy anything, you may find they have had a problem they are correcting.
I hope this information helps someone.
Hockster