If you mean it is weathering/rotting at the exposed edge where it attaches to the luff rail which is secured to the TC. Liff is a sailing term to name a part of a sail...in the RV world I use it to refer to the edge of the awning fabric that has a cord sewn in so it can be pulled thru the c shaped rail that holds it to the TC.
All you need to do because usually the awning has more fabric than needed to extend the canopy...is take the fabric to a good car upholstery shop and have them trim off the rotted fabric and sew in a new cord. If you are handy you should be able to remove the roller and fabric, but the shop can too, but it will cost.
Other thing is go on line to Dometic and get the part number for your fabric and a local dealer and order it...that 12 foot comment is totally bogus...can't your TC manufacturer give you the part number for the canopy, then you can get the fabric replacement number.
This will get you started.Spare Parts for RV Products
Pasted from web:
You can order parts for your Dometic RV product(s) directly by calling the retail sales department at 1-800-544-4881. Please be sure to have your model number available so the correct parts list can be obtained.
If you are in need of any Dometic RV refrigerator, air conditioner or A&E awning parts you can also call us at 1-800-544-4881 or purchase from any RV Dealer or Camping World location.
If we can be of any future service do not hesitate to contact us. Thank you for choosing Dometic.
Dometic RV Products Customer Support
customersupportcenter@dometicusa.com
Just out not on Dom site is a new product that has a tough plastic flex material that rolls around the fabric when in travel position...it is not an add on it is part of the new fabric I am ordering for my Slide awning...have to wait as it is so new...got that info from RV supply house who have info, not on Dom site yet!
2005 Lance 1161, 2004 Dodge CTD 3500 Dually 19.5's Stabiloads Roadmaster Sway, 2009 20' Raider 185 Pro Fish 90hp & 9.9 Yamaha vintage Penn elec.downriggers EZLoad roller trailer