Proper application of the perimeter edge is critical to the success of a roof system (steep- slope or low-slope) due to susceptibility of wind damage. Proper securement of the roof system and perimeter metal is required to eliminate damage from high velocity winds. Proper securement requirements are obtained through completion of perimeter metal calculations. It is also a code requirement that perimeter metal materials are certified by ANSI/ES-1. The IBC code provides further details of these requirements.
The other condition that is extremely important is the waterproofing of the fascia in conditions where the drainage of water occurs at the perimeter. This is a consistent condition in steep-slope applications or low-slope applications that drain at gutters or scuppers.