Subject: Windstorm Requirements
Submitted by: Bill Erickson
To be considered Fortified against windstorms in Florida, homes must include features that
address protection of the building envelope from windborne debris, wind resistant roof coverings
and underlayments as well as proof of a continuous load path from the roof to the foundation of
the building.
Building Envelope Protection: All entry doors, windows, skylights, patio doors and garage doors
must be tested and certified to meet impact resistance and pressure standards. If the units
themselves are not tested, then they must be protected by a protection system (storm shutter)
that meets the impact resistance standards. Systems must be compliant with ASTM E 1996,
SSTD-12 or Miami-Dade County protocol A 201.
Roof Construction: The roof framing, sheathing and covering all must be constructed to resist
wind pressures. In order to accomplish this, the following criteria need to be satisfied:
o
o
o
o
o
Gable end roof framing must be braced back to the interior portions of the roof and
ceiling structure (both top and bottom of trusses)
Roof decks must be at least 19/32” thick plywood and fastened to roof frame with
minimum 8d ring shank nails @ 6” on center throughout each panel and 4” on center directly
into the last truss or rafter on all gable ends.
All roof deck joints must be sealed by a self-adhering polymer modified bitumen-roofing
tape to provide a secondary moisture barrier (these materials are also referred to as “flexible
flashing”). Products must be installed per the manufacturer’s recommendations (some require
rolling after application).
Minimum 30# roofing felt (or equivalent) must be used as underlayment for the roof
covering.
Roof covering must be certified for use in hurricane regions (i.e. Miami-Dade approved
or ASTM D 3161 revised to 110 mph) and installed per manufacturer’s recommendations.
Only a single layer of covering is permitted.
Adequate Load Path: The load path from the roof to the foundation of the home must be readily
verifiable. This includes:
o
o
o
o
o
Hurricane straps or other hardware that connect the roof to the walls installed in per
manufacturer’s recommendations.
Concrete block walls vertically reinforced every 4 feet and at all corners and ends of
openings (minimum #4 re-bar)
Inter-story details strapped to provide a load path from the upper story to the lower
story.
Wall-to-foundation connection a minimum of once every four feet and at all corners and
wall openings.
Securely anchored connections for exterior structures such as carports and porches
that attach to the main structure of your home.