ASTM International E1646-95 Standard Test Method for Water Penetration of Exterior Metal Roof Panel Systems by  Uniform Static Air Pressure Difference

ASTM E 1646 test method covers the determination of resistance of exterior metal roof panel systems to water penetration when water is applied to the outdoor face simultaneously with a static air pressure at the outdoor face higher than the pressure at the indoor space, that is, positive pressure.

This test method is a specialized adaptation of test method  E331.

The purpose of this test method is to conduct quality assurance water penetration testing of the roof including panel side laps and structural connections.

The test method simulates a wind driven rain event that is imposed on sidelaps and rain that is free to drain while building a water head as it flows.

For that reason the slope of the roof plays a significant importance.

The test is conducted by attaching the chamber to the test specimen. A section of calibrated spray racks are set in place 12 inches above the specimen.

The calibrated spray racks shall deliver water uniformly against the roof surface at a minimum rate of five gallons per square foot per hour.

Pre-loading is a essential part of the testing procedure. The preload test pressure differences positive and negative are to be specified.

The positive preload pressure difference shall be greater of 75% of the live load or 50% of the building design positive wind pressure difference.

The positive test pressure shall be greater than or equal to 15 pounds per square foot. The negative preload pressure difference shall be 50% of the design wind uplift pressure difference.

Prior to testing a positive static air pressure differential preload is applied. This preload is applied for a minimum of 10 seconds. After applying the preload there is a two minute recovery period.

Then the specimen is preloaded with a negative static air pressure differential for a minimum of 10 seconds. After applying the preload there is a two minute recovery period.

This process is repeated for a total of three cycles.

The specified air pressure is applied for 15 minutes while applying the calibrated amount of water.

SITC has utilized this test method to assist our clients with their quality assurance testing of metal panel roof systems. They have found this test method accelerates their ability to qualify their new research and development projects.

Contact SITC if we can assist you with your ASTM 1646 testing.