According to ANSI A 250.8, the doors, frames and hardware reinforcings shall comply with the requirements of the following classification:

* Performance level per ANSI A250.4

The classification defines the model 1 as being a full flush door with a visible seam on the vertical edges. The model 2 is defined as a seamless door, however the fabrication methods are at the manufacturer's discretion.  Their is 3 types of construction:

• vertical seams edge filled and dressed smooth (lockseam on edge).
  
• intermittently welded seams, edge filled, dressed smooth.
  
• continuously welded seams dress smooth.

When an SDI specification is written, the type of construction for a model 2 door should be clearly defined to avoid misinterpretation.

This performance test includes a cycle test and a twist test. The duration is 250 000 cycles for a level C, 500 000 cycles for a level B and 1 000 000 cycles for a level A.

The deterioration of the door strength during the test, if any, is checked through a series of twist tests. These twist tests are performed before the cycle test begins and then at 25,000 cycle intervals for the first 100,000 cycles and at 50,000 cycle intervals for the balance of the test.

de La Fontaine products meet this standard using a 4070 door.  

The performance level C to A are achieve with a lockseam on edge door. Since the continuously welded construction is stronger, the CW door series automatically achieve these standard requirements.