The Truth About Shingle Warantees
When it comes to roofing products, most consumers consider the length of the warranty as a primary factor in the selection of asphalt shingles. Unfortunately, the length of the warranty does not necessarily indicate the useful lifetime of the material. Manufacturers have found that by limiting liability to manufacturing defects, they can dramatically increase warranty periods.
In general, warranty duration of asphalt shingles has increased 50% in the last 30 years. Of course part of this increase is due to improved manufacturing techniques and raw material formulations, but part of the increase is due simply to rewording of the warranties to limit the manufacturer's exposure by increasing installation requirements, excluding transfer of the warranty to new homeowners, and prorating the warranty.
3-Tab Asphalt Shingles generally have a warranty period that ranges from 20 to 30 years. Architectural Laminate Asphalt Shingles generally have a warranty period ranging from 30 years to 50 years on commercial buildings or "lifetime" on residential buildings. These limited warranties are commonly prorated and limited to the material costs only. You're on your own for labor, disposal fees, and accessories like vents, flashings, and underlayments.
What does prorating mean?
Just like tires or car batteries, shingle warranties are normally pro-rated. Should the material fail prior to the expiration of the warranty period, the amount of refund or credit issued by the manufacturer is proportional to the amount of time remaining in the warranty period. If your shingles fail prematurely due to a manufacturing defect, you'll need a 100% new roof. However, the benefit of the warranty may only be 20% of the cost of a new roof:
|Prorated Warranty Example|
A = number of affected squares = 25 squares
B = initial value of material = $100 per square
C = number of months remaining in warranty = 249 months
D = total length of warranty (in months) = 360 months
|Prorated Warranty Value||=||A x B x C||=||25 x $100 x 249||=||$1,729.17|
Of the original $2500 cost of the shingles, the warranty will only cover $1,729.17. In addition, no manufacturer's basic warranty covers labor, dump fees, flashing, ventilation, underlayments, or fasteners. Shingles only. All of the additional labor and material are the homeowner's responsibility.
Most popular shingle manufacturers provide standard warranties on their products at no additional cost, with upgraded warranties available for a fee, often only through certified contractors. The length of the material warranty should not be the greatest concern in the selection of a roofing system. The warranty itself does not offer a homeowner a guaranteed lifetime on the shingles, and does nothing to insure that they have been installed correctly.
Only a trusted manufacturer and qualified local contractor installing a complete system will guarantee the reliability of your roof over it's expected lifetime.