National Coatings Corporation highly recommends that one of the adhesion test procedures outlined below be performed on roofs prior to the application of an AcryShield roof coating system. Running these tests will help ensure that the coating will adhere properly once installed.
PROCEDURE #1
Once the roof has been cleaned and dried, press a 3 to 4 inch long piece of 2 inch clear packaging tape to the roof using hand pressure. Then, peel the tape off the roof. If it comes off easily, and or is laden with dirt, degraded roofing material and other particulates, the roof is not cleaned satisfactorily. Re-clean and dry the roof and repeat this test. This test should be conducted in several areas around the roof, especially in ponded or other dirty areas.
PROCEDURE #2
Apply the roof coating to the prepared roof surface and while still wet, imbed a 1 inch wide cloth strip. The strip should be 12 inches long, but imbed only about 6 inches of it. Allow this to dry. If wet adhesion properties are needed, adhere a 12 inch diameter by 2 inch sheet metal cylinder to the roof substrate using a caulk. When the caulk is dry, fill the area with water and wait for one week. After the dry/immersion period, attach a small fish scale (the kind used by sport fisherman, available at sporting goods stores) to the free end of the cloth strip. Carefully, cut the 1 inch wide sides of the strip that is imbedded in the coating, being careful not to cut into the roof substrate. Pull slowly on the fish scale, pulling the 1 inch wide cloth strip away from the roof substrate. Read the weight (force) required as the cloth strip is pulled away. This method is similar to the ASTM C-794 adhesion test.
For further information, please contact a National Coatings Technical Consultant.