Roof Underlayment for Asphalt Shingle Roofs
www.fema.gov
HURRICANE RECOVERY ADVISORY
Recovery Advisory No. 1  Roof Underlayment for Asphalt Shingle Roofs September 
2004 
Purpose: To provide recommended practices for use of roofing underlayment as an 
enhanced secondary water barrier in hurricane-prone areas (both coastal and 
inland).
Note: The underlayment options illustrated here are for asphalt shingle roofs. See FEMA 
publication 55, Coastal Construction Manual, for guidance concerning underlayment for other 
types of roofs.
[text box] 
This fact sheet provides general guidelines and recommended enhancements for 
improving upon typical practice. It is advisable to consult local building requirements for 
type and installation of underlayment, particularly if specific enhanced underlayment 
practices are required locally.
[end of text box]
Key Issues
 Verify proper attachment of roof sheathing before installing underlayment
 Lapping and fastening of underlayment and roof edge flashing
 Selection of underlayment material type
Sheathing Installation Options
The following three options are listed in order of decreasing resistance to 
long-term weather exposure following the loss of the roof covering. Option 1 
provides the greatest reliability for long-term exposure; it is advocated 
in heavily populated areas where the design wind speed is equal to or greater 
than 120 mph (3-second peak gust). Option 3 provides limited protection and is 
advocated only in areas with a modest population density and a design wind speed 
less than or equal to 110 mph (3-second peak gust).
Installation Sequence  Option 1 [endnote 1]
1. Before the roof covering is installed, have the deck inspected to verify that 
it is nailed as specified on the drawings.
2. Install self-adhering modified bitumen tape (4 inches wide, minimum) over 
sheathing joints; seal around deck penetrations with roof tape.
3. Broom clean deck before taping; roll tape with roller.
4. Apply a single layer of ASTM D 226 Type II (#30) felt.
5. Secure felt with low-profile, capped-head nails or thin metal disks 
(tincaps) attached with roofing nails.
6. Fasten at approximately 6 inches on center along the laps and at 
approximately 12 inches on center along two rows in the field of the sheet 
between the side laps.
7. Apply a single layer of self-adhering modified bitumen complying with ASTM 
D 1970 over the #30 felt throughout the roof area.
8. Seal the self-adhering sheet to the deck penetrations with roof tape or 
asphalt roof cement.
Installation Sequence  Option 2 [endnote 1]
1. Before the roof covering is installed, have the deck inspected to verify 
that it is nailed as specified on the drawings.
2. Install self-adhering modified bitumen tape (4 inches wide, minimum) over 
sheathing joints; seal around deck penetrations with roof tape.
3. Broom clean deck before taping; roll tape with roller.
4. Apply two layers of ASTM D 226 Type I (#15) felt with offset side laps.
5. Secure felt with low-profile, capped-head nails or thin metal disks 
(tincaps) attached with roofing nails.
6. Fasten at approximately 6 inches on center along the laps and at 
approximately 12 inches on center along a row in the field of the sheet between 
the side laps.
Installation Sequence  Option 3 [endnotes 1,2]
1. Before the roof covering is installed, have the deck inspected to verify 
that it is nailed as specified on the drawings.
2. Install self-adhering modified bitumen tape (4 inches wide, minimum) over 
sheathing joints; seal around deck penetrations with roof tape.
3. Broom clean deck before taping; roll tape with roller.
4. Apply a single layer of ASTM D 226 Type I (#15) felt.
5. Tack underlayment to hold in place before applying shingles.
Endnotes:
1 Note: If the building is within 3,000 feet of saltwater, stainless steel or 
hot-dip galvanized fasteners are recommended for the underlayment attachment.
2 Note: (1) If the roof slope is less than 4:12, tape and seal the deck at 
penetrations and follow the recommendations given in The NRCA Roofing 
and Waterproofing Manual, by the National Roofing Contractors Association. (2) 
With this option, the underlayment has limited blowoff resistance. 
Water infiltration resistance is provided by the taped and sealed sheathing 
panels. This option is intended for use where temporary or permanent 
repairs are likely to be made within several days after the roof covering is 
blown off.
General Notes
 Weave underlayment across valleys.
 Double-lap underlayment across ridges (unless there is a continuous ridge 
vent).
 Lap underlayment with minimum 6-inch leg turned up at wall intersections; 
lap wall weather barrier over turned-up roof underlayment.
Additional Resources
National Roofing Contractors Association (NRCA). The NRCA Roofing and 
Waterproofing Manual. (www.NRCA.net)
[End of Recovery Advisory No. 1]
Asphalt Shingle Roofing for High-Wind Regions
www.fema.gov
HURRICANE RECOVERY ADVISORY
Recovery Advisory No. 2  Asphalt Shingle Roofing for High-Wind Regions 
September 2004 
Purpose: To recommend practices for installing asphalt roof shingles that will 
enhance wind resistance in high-wind, hurricane-prone areas (both coastal and 
inland).
Key Issues
 Special installation methods are recommended for asphalt roof shingles used in 
high-wind, hurricane-prone areas (i.e., greater than 90-mph, 3-second peak 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. 1 for installation techniques in 
hurricane-prone areas.
Construction Guidance
1. Follow shingle installation procedures for enhanced wind resistance.
--Shingle installation at eaves
--Shingle installation at hips and ridges
--Shingle installation at rakes
2. Consider shingle physical properties.
--Fastener Pull-Through Resistance [note 3]
For Design Wind Speed [note 1] of >90 to 120 mph, minimum recommended 25 lb at 
70 degrees Fahrenheit.
For Design Wind Speed [note 1] of >120 mph, minimum recommended 30 lb.
--Bond Strength [note 3]
For Design Wind Speed [note 1] of >90 to 120 mph, minimum recommended 12 lb.
For Design Wind Speed [note 1] of >120 mph, minimum recommended 17 lb.
Notes
1. Design wind speed based on 3-second peak gust.
2. ASTM D 3462 specifies a minimum fastener pull-through resistance of 20 lb at 
70 F. If a higher resistance is desired, it must be specified.
3. Neither ASTM D 225 or D 3462 specify minimum bond strength. If minimum bond 
strength is desired, it must be specified.
--For organic-reinforced shingles, the standard is ASTM B 225, and the 
characteristics are relatively high fastener pull-through resistance.
--For fiberglass-reinforced shingles, the standard is ASTM D 3462, and the 
characteristics are considerable variation in fastener pull-through resistance 
offered by different products.
--For SBS modified bitumen shingles, a standard does not exist for this product. 
It is recommended that SBS modified bitumen shingles meet the physical 
properties specified in ASTM 3462. 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 hurricane-prone 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, hurricane-prone climates and consider organic shingles only in cool, 
hurricane-prone 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, shingle uplift loads should 
be calculated in accordance with UL 2390. Shingles having a bond strength (as 
determined from test method ASTM D 6381) that is at least twice as high (i.e., a 
minimum safety factor of 2) as the load calculated from UL 2390 should be 
specified/purchased.
[End of Recovery Advisory No. 2]
Tile Roofing for Hurricane-Prone Areas
www.fema.gov
HURRICANE RECOVERY ADVISORY
Recovery Advisory No. 3  Tile Roofing for Hurricane-Prone Areas November 2004 
Purpose: To provide recommended practices for designing and installing extruded 
concrete and clay tiles that will enhance wind resistance in hurricane-prone 
areas (both coastal and inland).
Key Issues
Missiles: Tile roofs are very vulnerable to breakage from wind-borne debris 
(missiles). Even when well attached, they can be easily broken by missiles. If a 
tile is broken, debris from a single tile can impact other tiles on the roof, 
which can lead to a progressive cascading failure. In addition, tile missiles 
can be blown a considerable distance and a substantial number have sufficient 
energy to penetrate shutters and glazing, and potentially cause injury. Where 
the basic wind speed is equal to or greater than 110 mph (3-second peak gust), 
the wind-borne debris issue is of greater concern than in lower wind speed 
regions. Note: There are currently no testing standards requiring roof tile 
systems to be debris impact resistant.
Attachment methods: Storm damage investigations revealed performance problems 
with mortar-set, mechanically-attached (screws or nails and supplementary 
clips when necessary) and foam-adhesive (adhesive-set) attachment methods. In 
many instances, the damage was due to poor installation. Investigations revealed 
that the mortar-set attachment method is typically much more susceptible to 
damage than are the other attachment methods. Therefore, in lieu of mortar-set, 
the mechanically-attached or foam-adhesive attachment methods in 
accordance with this Advisory are recommended.
To ensure quality installation, licensed contractors should be retained. This 
will help ensure proper permits are filed and local building code requirements 
are met. For foam-adhesive systems, it is highly recommended that installers 
be trained and certified by the foam manufacturer. 
Uplift loads and resistance: Calculate uplift loads and resistance in accordance 
with the Design and Construction Guidance section below. Load and resistance 
calculations should be performed by a qualified person (i.e., someone 
who is familiar with the calculation procedures and code requirements).
Corner and perimeter enhancements: Uplift loads are greatest in corners, 
followed by the perimeter and then the field of the roof (see Figure 1). 
However, for simplicity of application on smaller roof areas (e.g., most 
residences and smaller commercial buildings), use the attachment designed for 
the corner area throughout the entire roof area. 
Hips and ridges: Storm damage investigations have revealed that hip and ridge 
tiles attached with mortar are very susceptible to blow-off. Refer to the 
attachment guidance below for improved attachment methodology.
Quality control: During roof installation, installers should implement a quality 
control program in accordance with the Quality Control section below.
Design and Construction Guidance
1. Uplift Loads
In Florida, calculate loads and pressures on tiles in accordance with the 
current edition of the Florida Building Code (Section 1606.3.3). In other 
states, calculate loads in accordance with the current edition of the 
International Building Code (Section 1609.7.3).
As an alternate to calculating loads, design uplift pressures for the corner 
zones of Category II buildings are provided in tabular form in the Addendum to 
the Third Edition of the Concrete and Clay Roof Tile Installation Manual (see 
Tables 6, 6A, 7, and 7A). [note 1] 
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Classification of Buildings
Category I - Buildings that represent a low hazard to human life in the event 
of a failure
Category II - All other buildings not in Categories I, III, and IV
Category III - Buildings that represent a substantial hazard to human life
Category IV - Essential facilities
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Note: In addition to the tables referenced above, the Concrete and Clay Roof 
Tile Installation Manual contains other useful information pertaining to tile 
roofs. Accordingly, it is recommended that designers and installers of tile 
obtain a copy of the Manual and the Addendum. Hence, the tables are not 
incorporated in this Advisory.
2. Uplift Resistance
For mechanical attachment, the Concrete and Clay Roof Tile Installation Manual 
provides uplift resistance data for different types and numbers of fasteners and 
different deck thicknesses. For foam-adhesive-set systems, the Manual refers to 
the foam-adhesive manufacturers for uplift resistance data. Further, to improve 
performance where the basic wind speed is equal to or greater than 110 mph, it 
is recommended that a clip be installed on each tile in the first row of tiles 
at the eave for both mechanically-attached and foam-adhesive systems. 
For tiles mechanically attached to battens, it is recommended that the tile 
fasteners be of sufficient length to penetrate the underside of the sheathing by 
 minimum. For tiles mechanically attached to counter battens, it is 
recommended that the tile fasteners be of sufficient length to penetrate the 
underside of the horizontal counter battens by  minimum. It is recommended 
that the batten-to-batten connections be engineered.
For roofs within 3,000 feet of the ocean, straps, fasteners, and clips should be 
fabricated from stainless steel to ensure durability from the corrosive effects 
of salt spray.
3. Hips and Ridges
The Concrete and Clay Roof Tile Installation Manual gives guidance on two 
attachment methods for hip and ridge tiles: mortar-set or attachment to a ridge 
board. Based on post-disaster field investigations, use of a ridge board is 
recommended. For attachment of the board, refer to Table 21 in the Addendum to 
the Concrete and Clay Roof Tile Installation Manual. 
Fasten the tiles to the ridge board with screws (1 minimum penetration into the 
ridge board) and use both adhesive and clips at the overlaps. 
For roofs within 3,000 feet of the ocean, straps, fasteners, and clips should be 
fabricated from stainless steel to ensure durability from the corrosive effects 
of salt spray.
4. Critical and Essential Buildings (Category III or IV)
Critical and essential buildings are buildings that are expected to remain 
operational during a severe wind event such as a hurricane. It is possible that 
people may be arriving or departing from the critical or essential facility 
during a hurricane. If a missile strikes a tile roof when people are outside the 
building, those people may be struck by tile debris dislodged by the missile 
strike. Tile debris may also damage the facility. It is for these reasons that 
tiles are not recommended on critical or essential buildings.
If it is decided to use tile on a critical or essential facility and if the 
tiles are mechanically attached, it is recommended that clips be installed at 
all tiles in the corner, ridge, perimeter, and hip zones (see ASCE 7-02 for the 
width of these zones). (See Figure 1)
Figure 1. For critical and essential facilities, clip all tiles in the corner, 
ridge, perimeter, and hip zones. NOTE: See ASCE 7 for zone width.
5. Quality Control
It is recommended that the applicator designate an individual to perform quality 
control (QC) inspections. That person should be on the roof during the tile 
installation process (the QC person could be a working member of the crew). The 
QC person should understand the attachment requirements for the system being 
installed (e.g., the type and number of fasteners per tile for mechanically 
attached systems and the size and location of the adhesive for foam-adhesive 
systems) and have authority to correct noncompliant work. The QC person should 
ensure that the correct type, size, and quantity of fasteners are being 
installed.
For foam-adhesive systems, the QC person should ensure that the foam is being 
applied by properly trained applicators and that the work is in accordance with 
the foam manufacturers application instructions. At least one tile per square 
(100 square feet) should be pulled up to confirm the foam provides the minimum 
required contact area and is correctly located.
If tile is installed on a critical or essential building, it is recommended that 
the owner retain a qualified architect, engineer, or roof consultant to provide 
full-time field observations during application.
Note 1. The Manual can be purchased online from the Florida Roofing, Sheet Metal 
and Air Conditioning Contractors Association, Inc. at www.floridaroof.com or by 
calling (407) 671-3772. Holders of the Third Edition of the Manual who do 
not have a copy of the Addendum can download it from this web site.
[end of Recovery Advisory No. 3]