Why are there White Stains on the side of my RV?

How To Clean And Repair Your RV's Rubber Roof | The Fun ...

http://rv-roadtrips.thefuntimesguide.com/

Tue, 09 Sep 2008 10:26:15 -0700

RV roofs are typically made from Ethylene Propylene Diene Monomer (EPDM). Over time, your RV roof will develop a chalky surface which is totally normal.

This chalking will only affect about 10% of the roof’s original thickness. Regular cleaning will help reduce the amount of chalk buildup and help prevent the white stains seen on the sides of many older RVs.

Read more ...