Check to make sure the weather is right before you start painting your roof. Make sure that rain isn't forecast for the next few days, and the temperature should be over 50 degrees Fahrenheit. Temperatures lower than that, or a humid environment, can damage the roof coating before it dries.
Make sure there are no leaks, cracks or deterioration in your roof. If there are, tend to them before beginning to paint a coating onto your roof.
Clean your roof. You can accomplish this with a wire brush, rough sandpaper or a putty knife to remove any flakes from the rooftop. Sweep any debris away with a broom, and hose the entire thing down. Do not begin painting until the roof is dry.
Use the paint brush to paint a layer of primer over all of the seams and edges of the roof. This will help prevent future cracks and leaks. Overlap coating at any edges you meet by one inch, and make sure you completely cover any screw heads.
Mix the roof coating as per the manufacturer's instructions as you wait for the patching cement to dry.
Apply the coating to the roof with a roof brush or coating paint roller. Make sure you only start coating after the primer has dried. Also make sure you apply the coating according to the instructions on the manufacturer's label. Different brands may specify varying instructions regarding how to properly apply roof coating. For example, some brands will recommend applying a minimum of three coats instead of two.
Wait for the roof coating to try. Apply a second coat if needed. If you have applied coating to the roof properly, it should effectively help reduce the temperature of your home.