Secondary Water Resistance
A proper SWR will increase your insurance credits significantly depending on the insurance carrier in question. However, having a SWR or not is the million dollar question. To understand whether or not the home does or does not have an SWR, you must first understand the nuances associated with this question.
The 2001 Florida Building Code references the SWR with any reroof or new roof. The difference is that the FBC definition of an SWR is NOT the definition used by the Office of Insurance Regulation on the wind mitigation inspection report (OIR-B1-1802), so just because a roof meets the 2001 FBC, DOES NOT mean it has a qualifying SWR.
Many inspectors incorrectly complete this question because of this confusion. In order to qualify for an OIR SWR credit, you must have a self adhering modified bitumen roofing underlayment applied directly to the roof sheathing or foam SWR sprayed from inside the attic (not foam insulation!).
Photographs of the application of the SWR or other documentation from the roofer or homeowner are required to accompany the report to validate when the SWR is not visible.