Three Factors that Architects, Builders and Property Owners Must Address Before they Choose a Roof

Fire Safety and Protectionhave been chemically treated for fire retardancy.
Fire safety is a particularly important consideration,Wind Resistance
since the roof is vulnerable to fire from overhead orUL also tests shingle performance against high winds.
airborne sources.The fire resistance of roofingTo qualify for the UL wind-resistant label, shingles
materials is tested by themust withstand continuous test winds of at least 60
Underwriters’Laboratories, Inc. (UL), anmiles per hour for two hours without a shingle tab
independent, not-for-profit public safety testinglifting. Wind-resistant shingles demonstrated their
laboratory. UL established the standard for theeffectiveness under hurricane conditions during the
testing of roofing materials with the assistance ofwinds brought to Florida in 1992 by Hurricane
nationally recognized fireauthorities.Andrew, which at the time was the worst hurricane
Manufacturers voluntarily submit materials for testing.ever recorded in the United States.
The materialsthen are classified and labeled accordingSelf-sealing asphalt shingles that bear the UL
to the classes below. The American Society forwind-resistant label are manufactured with a
Testing and Materials (ASTM) is a voluntaryfactory-applied adhesive. Once the shingles are
organization concerned with the development ofapplied, the sun activates the preapplied thermoplastic
consensus standards,testing procedures, andsealant and each shingle is bonded to the one below
specifications.it. Although self-sealers originally were developed
Class A. The highest fire-resistance rating for roofingspecifically for high-wind areas, they are standard in
as per ASTM E-108. This class rating indicates thatmost parts of the country today.
the roofing material is able to withstand severeEstimating Life Expectancy
exposure to fire that originates from sources outsideIn addition to fire and wind ratings, roof coverings
the building.have a life expectancy. Manufacturers offer a
Class B. This fire-resistance rating indicates that theguarantee or warranty for their products. For
roofing material is able to withstand moderateexample, most of today’s asphalt shingles are
exposure to fire that originates from sources outsidedesigned to provide satisfactory service for 15 to 25
the building.years.
Class C. This fire-resistance rating indicates that theGenerally, the longer the life expectancy, the more
roofing material is able to withstand light exposure toexpensive the shingle material. You might find,
fire that originates from sources outside the building.however, that a more expensive shingle is the most
Many communities require new roof coverings toeconomical in the long run because the cost of
meet at least theUL Class C standard. Thismaterials and labor is amortized over a longer period
requirement has the backing of nationally recognizedof time. Keep in mind that while the labor cost to
authorities such as the National Fire Protectionapply the shingles varies with the product, it is the
Association and the International Association of Firesame whether the life expectancy of the shingle is 15
Chiefs. Some roofing materials, such as slate and clayor 25 years.
tile, offer natural fire protection. Asphalt shingles areEstimate the probable annual cost of a new roof by
manufactured to meet the Class C standard oradding the cost of labor and materials and then
better. Readily combustible materials, such as woodendividing the total by the shingle’s design life.
shingles, do not meet the UL standard unless they