Guide To Mitigation Features
A proven 2001 FBC (or 1994 SFBC) equivalent roof covering on all roof systems that are structurally attached or over living space. This is usually determined by construction permit, and in limited cases through research of the actual materials used.
Roof to Wall Connection
Many homes are constructed with metal clips, single wraps or double wraps securing the roof structure to the walls of the home. They need to be properly installed and on every truss or rafter to qualify, making attic access very important for the inspector.
Roof Deck Attachment
The roof deck of the home, often plywood, must be securely fastened to the trusses or rafters of the main roof structure. The inspector carefully measures and records the nail size used and the spacing of the nails. Again, attic access is very important.
Actuarial and engineering studies (such as this one in 2008 by Applied Research Associates) demonstrate how a roof that consists almost entirely of hip shapes fares significantly better than other roof shapes when subjected to hurricane-force winds. The inspector carefully documents all of the non-hip features of the home and compares these to the length of the entire perimeter.
Secondary Water Resistance
Secondary water barriers can be installed in the attic space and also on top of the roof deck. They are in most cases optional and come at additional expense. Paperwork is required to prove the materials that were used and certify the installation meets the requirements listed on the windstorm inspection form.
Opening Protective Devices, such as shutters or impact-tested windows, must either be on all openings, or all openings containing glass, depending on the specific requirements of your insurance company. To count as Class A protection, the opening protection product must have been tested to meet the 9 lb. missile test, among other tests. An example of a product being tested can be found Here. An example of various products passing and failing the impact test can be found Here.