We had the same sort of problem with our awning... sun-damaged weather shield... it actually separated the dual-layer awning fabric up there and in a rain would cause a water-balloon effect.
In addition, there was some damage to one of the upright awning supports from the previous owner. It was bent or torqued/twisted just enough to make it difficult setting up or closing the awning.
After careful consideration, we decided to replace the whole awning.
We chose a Dometic 8500 Plus awning with it's automatic rain shed feature. And we had it done at... CAMPING WORLD.
Yes, believe it or not, they had a sale on (well, we WAITED for them to have one) and got the old awning removed, the new one installed. We got the Product Protection Plan for it to extend the warranty at any Camping World shop in the country. We have used it several times since and been VERY pleased. (the awning... not the Protection Plan
)
Lenchernit... with an awning as long as what you are wanting, I think you'll want one of those center rafter supports. One of our camping friends in Georgia has a 34-foot trailer and a LONG awning. They added this center rafter support and he says it's a good idea for such a long awning.
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Dave & Cindy
'99 Chevrolet 2500 ext. cab (2WD)
5.3 liter V8, 3.73LS, Prodigy, Hensley Arrow
2004 Sunline Solaris SE T-2499 #5527