This link has some good advice how to keep your awning looking good and waterproof. The big tip is don't use any soap/detergent...
http://www.caravan-advice.co.uk/awning-c...ml#.WAUImuzTVpU
Cleaning Your Awning
Always try to keep your awning as clean as possible which will help to keep it waterproof. Some of our awning care advice :
The best way to clean the awning is when you have erected it on the caravan so that you can reach all the sides plus the roof with a step ladder.
Only use just warm water with a soft brush. Anything stronger (even just washing-up liquid) could remove the waterproofing or damage the canvas.
Don't use a pressure washer as this may also cause damage, not only to the canvas but also to the seams.
Only clean the awning when it is completely dry.
Sometimes just brushing off mud or bird poo when it has dried is better than wetting the canvas and then trying to get it off.
If warm water doesn't remove the stains, you may have to buy a specialist awning cleaner.
If you do have to buy some always try it first on an inconspicuous area of the awning just in case it marks the canvas.
Storing Your Awning
The most important point to remember when storing your awning is to always pack it away when it is completely dry. If it is wet, or even just damp, when you take down your awning you must dry it out completely at home to prevent any mildew forming.
The poles must also be completely dry before storing to prevent rust.
Fibreglass poles only need to be wiped with a damp cloth.
Steel or aluminium poles should be wiped once a year with either silicone or wax polish which will help to prevent any rust.
When you are not using your awning store it in a dry, aired place.
Don't leave the awning in your caravan over winter just in case any condensation forms in your caravan. The best place is a cool and dry garage.