Copyed from jayco's blog
http://blog.jayco.com/caring-for-your-rv-awning/
1.One of the best ways to keep the fabric looking good and to delay the need for deep or vigorous cleaning is to hose fabrics off on a monthly basis with clear water. This practice will help prevent dirt from becoming deeply imbedded in the fabric. In most environments, a thorough cleaning will be needed every two to three years.
2.When it’s time for a thorough cleaning, the fabric can be cleaned while still on an awning frame. For vinyl fabric – Use a soft brush and warm water with soap. For acrylic fabric, use a stiff brush and warm water with soap.
3.When cleaning the fabric, it is important to observe the following:
•Caution: Do not use oil based cleaners or any caustic, granulated, or abrasive type cleaners on your Jayco RV awning.
•Always use a natural soap, never detergent.
•Water should be cold to lukewarm, never more than 100°F.
•Air-dry only.
•Never apply heat to the fabric.
Always allow the fabric to dry thoroughly before rolling up the awning to avoid mildew. Vinyl-coated polyester fabrics are mildew resistant because of a chemical biocide in their coating. Under ordinary conditions, mildew will not appear. However, in areas where high temperature and humidity are common, mildew can be a problem and may require the material to be washed more frequently than in cooler, drier climates. To clean mildew from a unit’s awning, thoroughly rinse the fabric with clean water and allow to air dry completely before rolling it up.