This method is suitable for testing the decay-preventive efficacy of preservative formulations used for the protection of exterior joinery when they are applied to non-durable timber by specified treating methods and protected by conventional finishing systems (i.e. Use Category 3A).
The test employs simulated joinery units (millwork) (L-joints) which are placed out of doors, out of contact with the ground and are thus exposed to the normal environmental and ecological conditions similar to those of exterior joinery.The test unit specified is designed to simulate the lower joint of the opening light of an external window frame and is therefore protected with a conventional finishing system. To ensure challenge to the preserving system comparable to that met at a lower joint in practice, the cross-cut ends of the unit are sealed to prevent access of moisture and micro-organisms but the test joint itself is not sealed. To ensure uniformity of hazard the finish seal over the joint is broken prior to exposure of the test unit. The test unit has no features that shed water and is designed to exaggerate the decay hazard.
The method is standardized as AWPA Standard E9 (available from the AWPA) and EU Standard EN330.