Adhesion:

All paints should be tested for adhesion and flexibility before using.  Apply 1 to 2 coats of the test paint to several one square foot pieces of the facing, and allow to dry for one to two days at room temperature.  When dry, apply masking tape over the painted surface and rub well to insure intimate contact.  Check adhesion by removing the masking tape at both slow and fast speeds.  If the paint film cannot be removed with the masking tape, then adhesion is good.  The paint adhesion is satisfactory if the paint film comes off with the masking tape and provides some resistance to the removal (similar to removing masking tape on painted walls at home).  The adhesion is not satisfactory if the paint film is removed easily, with little or no resistance.

 

Flexibility:

Apply test paint and allow to dry as above.  When dry, crumble the painted facing into a tight round ball as though you were going to throw it into the waste basket.  Then immediately unroll to its original flat shape.  The paint should be flexible and not crack or flake off during this test.  The facing is a flexible membrane and will elongate or shrink with changes in the temperature and humidity.  The paint must be flexible and remain adhered to the facing during changes in temperature and humidity.    It should be noted that the application of a paint or coating to the surface of a facing may change the flame spread and smoke developed ratings.