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Asphalt Shingle Roofing for High-Wind Regions
Home Builder’s Guide to Coastal Construction
FEMA 499/June 2005
Technical Fact Sheet No. 20

Purpose: To recommend practices for installing asphalt roof shingles that will
enhance wind resistance in high-wind, coastal regions.

Key Issues
--Special installation methods are recommended for asphalt roof shingles used in
high-wind, coastal regions (i.e., greater than 90-mph gust design wind speed).
--Use wind-resistance ratings to choose among shingles, but do not rely on
ratings for performance.
--Consult local building code for specific installation requirements.
Requirements may vary locally.
--Always use underlayment. See Fact Sheet No. 19 for installation techniques in
coastal areas.
--Pay close attention to roof-to-wall flashing and use enhanced flashing
techniques (see Fact Sheet No. 24).

Construction Guidance
1.  Follow shingle installation procedures for enhanced wind resistance.

2.  Consider shingle physical properties.

Properties: Fastener Pull-Through Resistance (ASTM D 3462 specifies a minimum
fastener pull-through resistance of 20 pounds at 73 degrees Fahrenheit. If a
higher resistance is desired, it must be specified.)
Design Wind Speed greater than 90 miles per hour to 120 miles per hour (Design
wind speed based on 3-second peak gust): Minimum recommended fastener pull-
through resistance 25 pounds at 73 degrees Fahrenheit.
Design Wind Speed greater than 120 miles per hour: Minimum recommended fastener
pull-through resistance 30 pounds.

Shingle Type: Organic-Reinforced
Standard: ASTM D 225
Characteristics: Relatively high fastener pull-through resistance

Shingle Type: Fiberglass-Reinforced
Standard: ASTM D 3462
Characteristics: Considerable variation in fastener pull-through resistance
offered by different products

Shingle Type: SBS Modified Bitumen
Standard: A standard does not exist for this product. It is recommended that SBS
Modified Bitumen Shingles meet the physical properties specified in ASTM 3462.
Characteristics: Because of the flexibility imparted by the SBS polymers, this
type of shingle is less likely to tear if the tabs are lifted in a windstorm.

3.  Ensure that the fastening equipment and method results in properly driven
roofing nails for maximum blow-off resistance. The minimum required bond
strength must be specified (see Wind-Resistance Ratings, below).

Fastener Guidelines
--Use roofing nails that extend through the underside of the roof sheathing, or
a minimum of 3/4 inch into planking.
--Use roofing nails instead of staples.
--Use stainless steel nails when building within 3,000 feet of saltwater.

Weathering and Durability
Durability ratings are relative and are not standardized among manufacturers.
However, selecting a shingle with a longer warranty (e.g., 30-year instead of
20-year) should provide greater durability in coastal climates and elsewhere.

Organic-reinforced shingles are generally more resistant to tab tear-off but
tend to degrade faster in warm climates. Use fiberglass-reinforced shingles in
warm coastal climates and consider organic shingles only in cool coastal
climates. Modified bitumen shingles may also be considered for improved tear-off
resistance of tabs. Organic-reinforced shingles have limited fire resistance –
verify compliance with code and avoid using in areas prone to wildfires.

After the shingles have been exposed to sufficient sunshine to activate the
sealant, inspect roofing to ensure that the tabs have sealed. Also, shingles
should be of “interlocking” type if seal strips are not present.

Wind-Resistance Ratings
Wind resistance determined by test methods ASTM D 3161 and UL 997 does not
provide adequate information regarding the wind performance of shingles, even
when shingles are tested at the highest fan speed prescribed in the standard.
Rather than rely on D 3161 or UL 997 test data, wind resistance of shingles
should be determined in accordance with UL 2390. Shingles that have been
evaluated in accordance with UL 2390 have a Class D (90 mph), G (120 mph), or H
(150 mph) rating. Select shingles that have a class rating equal to or greater
than the basic wind speed specified in the building code. If the building is
sited in Exposure D, or is greater than 60 feet tall, or is a Category III or
IV, or is sited on an abrupt change in topography (such as an isolated hill,
ridge, or escarpment), consult the shingle manufacturer. (Note: for definitions
of Exposure D and Category III and IV, refer to ASCE 7.)