FEMA P55 Coastal Construction Manual, Fourth Edition - Mad Cad

Volume II Designing the builDing envelope 11
11.2.1.2 Wind-Borne Debris
If a solid door is hit with wind-borne debris, the debris may penetrate the door, but in most cases, the debris
opening will not be large enough to result in signifcant water infltration or in a substantial increase in
internal pressure. Terefore, in wind-borne debris regions, except for glazed vision panels and glass doors,
ASCE 7, IBC, and IRC do not require doors to resist wind-borne debris. However, the 2007 FBC requires
all exterior doors in the High-Velocity Hurricane Zone (as defned in the FBC) to be tested for wind-borne
debris resistance.
It is possible for wind-borne debris to cause door latch or hinge
failure, resulting in the door being pushed open, an increase in
internal pressure, and potentially the entrance of a signifcant
amount of wind-driven rain. As a conservative measure in windborne
debris regions, solid personnel door assemblies could be
specifed that resist the test missile load specifed in ASTM
E1996. Test Missile C is applicable where the basic wind speed
is less than 164 mph. Test Missile D is applicable where the basic wind speed is 164 mph or greater. 5 See
Section 11.3.1.2 regarding wind-borne debris testing. If wind-borne
debris-resistant garage doors are desired,
the designer should specify testing in accordance with ANSI/DASMA 115.
11.2.1.3 Durability
For door assemblies to achieve good wind performance, it is necessary to avoid strength degradation caused
by corrosion and termites. To avoid corrosion problems with metal doors or frames, anodized aluminum or
galvanized doors and frames and stainless steel frame anchors and hardware are recommended for buildings
within 3,000 feet of an ocean shoreline (including sounds and back bays). Galvanized steel doors and frames
should be painted for additional protection. Fiberglass doors may also be used with wood frames.
In areas with severe termite problems, metal door assemblies are recommended. If concrete, masonry, or
metal wall construction is used to eliminate termite problems, it is recommended that wood not be specifed
for blocking or nailers. If wood is specifed, see “Material Durability in Coastal Environments,” a resource
document available on the Residential Coastal Construction Web site, for information on wood treatment
methods.
11.2.1.4 Water Infltration
Heavy rain that accompanies high winds can cause signifcant wind-driven water infltration. Te magnitude
of the problem increases with the wind speed. Leakage can occur between the door and its frame, the frame
and the wall, and the threshold and the door. When wind speeds approach 150 mph, some leakage should be
anticipated because of the high-wind pressures and numerous opportunities for leakage path development. 6
5 The 164-mph basic wind speed is based on ASCE 7-10, Risk Category II buildings. If ASCE 7-05 or an earlier version is used, the
equivalent wind speed trigger is 130 mph.
6 The 150-mph basic wind speed is based on ASCE 7-10, Risk Category II buildings. If ASCE 7-05 or an earlier version is used, the
equivalent wind speed trigger is 120 mph.
COASTAL CONSTRUCTION MANUAL
Cross referenCe
For more information about
wind-borne debris and glazing in
doors, see Section 11.3.1.2.
11-7