I have a flat Rubber Roof. It has some cracks & needs a coating.

http://www.henry.com/Cool_Roof_Coatings.28.0.html

Have a look at this webpage. Scroll down to the botttom. If you know for
sure you have a "rubber" roof, selcect EPDM/Hypalon from the drop down menu.

This will give you a list of appropriate coatings. Henry's is a reputable
company that makes good products. They can be bought in 1's or 5 gallon
pails at Home Depot/ Lowes etc in the "roofing" section. Many can be
"rolled" right onto your existing roof with a large roller (available in the
same area at HD) just like "paint", especially the white "rubber" roof
coating types. They ve been applied by tens of thousands of homeowners in
hot climates like AZ and FL.

These coatings are good for sealing "cracks".

Check with the manufacturer of the roof . If it is truly a single ply
'rubber' roof, it can be destroyed by some materials.

Try and follow this previous advice if you can find out who made the
membrane. My inlaws place had a EPDM (white rubber roof, made of 3-4 thin
layers of rubber ) membrane made by tire MFG "Firestone" on their place.
It is often used for mobile home or RV roofs.