Your Pace Arrow has a TPO roof made by Alpha Systems. Here is what Alpha Systems says about cleaning
"As the next generation to EPDM roofing, Alpha Systems introduced Royal Tuff-Ply thermoplastic polyolefin (TPO) roofing to the RV industry in 1994. It is another attractive and lightweight alternative to metal roofing. TPO represents the latest advance in plastic technology and will provide many years of performance in products on which it is use.
Tuff-Ply TPO sheeting provides tear and puncture resistance 20 to 50 percent higher than EPDM rubber. The material offers excellent UV protection, will not retain odors and is resistant to rot. Tuff-Ply is easy to clean and resistant to mold, algae, fungus and other biological agents. It is easy to repair through an environmentally friendly heat welding process.
Alpha Systems also manufactures the roofing adhesives and sealants necessary to best fit your manufacturing or construction applications of Royal Tuff-Ply TPO.
Cleaning and Maintaining the Royal Tuff-Ply Roof
Proper care, cleaning and maintenance of TPO roofing is quite simple due to the basic properties and longevity of the material. Periodic cleaning is the primary maintenance needed. Alpha Systems recommends using Murphy's Oil Soap® with a soft nylon brush or sponge to clean Tuff-Ply.
DO NOT USE SOLID OR GRANULATED CLEANERS, as they will mar the natural finish.
DO NOT USE ARMOR-ALL® OR OTHER OIL OR SOLVENT-BASED CLEANERS, as they will leave a slick surface and possibly damage the membrane.
A thorough cleaning with moderate scrubbing action, per the suggestions above, should remove most stains and keep the roof looking good. For removal of more stubborn stains, contact Alpha Systems Customer Service at (574-295-5206).
Annual roof inspection is recommended. Check the membrane for possible damage and check the caulk or lap sealant used in all termination areas and around all accessories and fasteners."
Their website is www.alphasystemsinc.com