Roof Warranties RAND Engineering Architecture, DPC

By Stephen Varone. AIA and Peter Varsalona. PE

As president of my condominium association, I am responsible for overseeing the installation of a new roof on our building. What kind of warranty should we ask for with a roof replacement? What exactly should the warranty cover and for how long? Who's responsible if the roof leaks: the contractor or the manufacturer? How much extra should we expect to pay for a reasonable warranty?

A No Dollar Limit warranty reimburses owners for the full replacement cost of the roof for the entire term of the warranty.

Roof warranties come in three basic types: materials only, materials and labor on a pro-rated basis, and No Dollar Limit (NDL). Materials-only warranties are worth little if anything because roof replacement projects that turn out badly are almost always caused by improper installation and/or poor design, not defective roofing materials. A pro-rated labor-and-materials warranty covers poor workmanship, but for a lesser amount with each passing year. Toward the end of the term in a pro-rated warranty, you would receive only a fraction of the replacement cost for a new roof.

The third type of warranty, an NDL—is the best and most cost-efficient type of guarantee to get for your roof for the long term. A NDL warranty will reimburse you for the full replacement cost of the roof—whether the deficiencies were caused by poor materials or labor—for the full term of the warranty. For example, if a roof with a 20-year NDL starts leaking in the 19 th year, the manufacturer will pay the full cost to repair or replace it.

NDL warranties usually come in 15- and 20-year terms. In addition to the extra five years of coverage, the 20-year NDL roof typically has one or two extra layers of membrane than a roof covered by a 15-year NDL. (Warranties for 12-year terms or shorter are usually pro-rated.)

Manufacturers offering NDL warranties require that the roofing materials be installed by contractors who are certified by that manufacturer. The manufacturer will provide a list of certified contractors in your area, so your engineer or architect should send bids for the project only to those companies on the list. If subcontractors will be working on the project, the manufacturer must certify them as well. You should be aware that a contractor certified to install a roof covered by a 12-year pro-rated warranty is not necessarily certified by that same manufacturer to install a roof covered by a 20-year NDL warranty (sometimes called Gold or Platinum status coverage). Double check with the manufacturer if there’s any question about the certification level of a contractor on the list.

Under the agreement between the manufacturer and the contractor, for the first two years the contractor typically assumes responsibility for roof problems caused by poor installation. After that initial period, and for the rest of the term of the warranty, the manufacturer takes over responsibility for roofing problems, but with limitations and exclusions (see below). If the contractor goes out of business, it is the manufacturer’s responsibility to find another contractor who will make repairs to the roof, without charge to the building’s owner if it is NDL coverage.

Limitations and Exclusions

A common misconception about long-term warranties is that they are all-inclusive insurance policies that guarantee that the roofing system will never leak. Warranties generally stipulate that the manufacturer will repair leaks caused only by specific items covered under the warranty. Every warranty, even the most comprehensive NDL, has limitations and exclusions designed to significantly limit the manufacturer’s liability.

Warranties do not cover poor design flaws that contribute to leaks, such as ponding.

Chief among those exclusions is that warranties typically cover just the roof surface itself and the base flashing (the part of the roof membrane that extends up parapet and bulkhead walls to protect the seam of the roof and the wall.) Leakage caused by roof-level components such as parapet walls, copings, bulkheads, pavers, and roof decks, for example, are usually not covered.

Nor will warranties cover poor design flaws that may contribute to leaks. For example, most manufacturers will void the warranty if water ponds on the roof for longer than 24 or 48 hours, as this is probably caused by poor drainage from an improperly pitched roof. Roofs without counterflashing (usually a copper strip imbedded into the parapet wall that protects the seam of the base flashing) will also be a reason to void a warranty. Manufacturers can even contest specific details of the roof design, such as base flashing that does not extend far enough up the parapet walls as specified.

Other exclusions may include:

    Lack of proper roof maintenance. People walking on the roof or using it for recreational purposes. Movement or cracking of the roof deck or of the building itself. Exposing the roof to chemicals, grease, oil, etc. Any repairs, modifications or additions to the roof not authorized by the roofing manufacturer.

The best way to decrease the likelihood of the warranty being voided is to get the manufacturer involved in the project from the onset. Before beginning a particularly complex roof installation, the engineer or architect may even chose to submit a draft of the drawings and specifications to the manufacturer to verify which parts of the project scope they will cover or exclude. It will also give the manufacturer an opportunity to review the design details (such as base flashing) and note which ones are potential trouble spots that could risk the terms of the warranty. Necessary modifications can then be made to the design so that the new roof will be in accordance with the warranty. On more routine roofing projects, the engineer or architect should at least discuss with one of the manufacturer’s representatives any aspects of the design or installation that may subsequently cause concern for the manufacturer regarding issuance of the warranty.

The manufacturer should also be asked to send a representative to the site at least twice a month during the repair phase to make sure that the contractor is installing the roofing materials properly and that there aren’t any conditions that could adversely affect the roof’s performance. Once the job is completed, the manufacturer should conduct a final visit to give final approval on the quality of the project.

It is the responsibility of the board to perform regular maintenance on the roof and the surrounding roof structure to ensure the warranty remains valid. Drains should be kept clear at all times and periodically cleaned out, debris should be kept off the roofing surface, pitch pans (which cover penetrations from roof structures such as ventilation stacks) should be properly sealed, and residents may need to be reminded that recreational use of the roof is not permitted.

If you’re planning to add a roof deck in the future, you will need to get what is called an "overburden clause" from the roofing manufacturer. This clause specifies additional requirements, such as proper protection of the roof surface, that must be met so the new roof structure does not damage the underlying membranes and the warranty can remain in effect. You won’t be able to get an overburden clause for a roof that has already been replaced without having the additional structural and waterproofing protection that a roof deck demands.

Repairs First, Roof Last

Before you move ahead with replacing your roof, you should make sure that the rest of the roof-level structures, such as parapets, bulkheads, and copings, are in sound condition. It does no good to install a new roof without fixing deteriorated parapet walls, missing bricks, open mortar joints, or cracked copings. These types of defects should be repaired before installing a new roof because water infiltration will saturate the new roofing membranes and void your warranty. Another reason to have these repairs done before the new roof is laid down is that tools, scaffolds, and debris from fixing the other parts of the roof or the facades may damage the new membrane, nullifying your warranty.

Repairs done after the roof is replaced must be made by a contractor certified by the manufacturer.

Keep in mind that any repairs done after the new roof is in place must be made by a contractor certified by the manufacturer. The board, in turn, should notify the manufacturer of the repairs made so it can be noted in your warranty file. Keep all records of the repairs in the board’s files as well.

Generally speaking, a typical roof replacement project will cost approximately $17 to $20 a square foot, including the NDL warranty. A 20-year NDL warranty will usually cost up to $1 more per square foot than a 15-year NDL, which, considering the added coverage, is well worth it.

Warranties don’t cover everything, and in and of themselves, they won’t keep your roof from leaking. But a roof backed by a NDL warranty from a reputable manufacturer and properly installed by a certified contractor should keep you dry for many years to come.

Stephen Varone , AIA is president and Peter Varsalona , PE is principal of RAND Engineering & Architecture, DPC . This column was originally published in the December 2003 issue of Habitat Magazine .

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