This project was an existing spray foam and coated roof system (SFRS) installed by another contractor, the coating had completely deteriorated and the roof leaked. The original foam only averaged ½” thick ( 1 ½” inches thick should be the minimum) and was blistered and cracked. The drains, well they speak for themselves (see image).
When a properly installed SFRS reaches its life expectancy it normally only requires a recoating over the existing coating, this roof was so bad we recommend a complete tear off including the existing BUR that was below the foam. Once the tear off was complete we came back with approved primer, 1 ½” inches of roof foam, 2 gallons per square silicone coating with granules broadcasted into the top coat.
The original design of this roof only had two interior drains, as part of our re-roof we installed an over flow drain to the exterior of the building.