A recurring dream for maintenance managers is to have a building with a roof that provides leak-free service forever.  That's not possible, but maintenance managers can maximize service for the design life of a roof system through preventative maintenance (PM).  A state-of-the-art PM program protects the roofing investment and adds years to the system's serviceable life.

Such a program also can reveal minor problems before damage spreads.  If undetected, minor problems can escalate until they become expensive to fix.

Establishing a program
An effective PM program schedules inspections and required repairs.  The best time to start a PM program is during the design and installation of a new roof system.  The program should include the following elements:

• historical file.  At the time of acceptance, an owner should require that key information be compiled and submitted as a part of close-out documentation.  Information should include:
• as built plans and specifications, including addenda
• current roof plans showing penetrations and equipment
• minutes of pre-bid and pre-construction meetings
• shop drawings and product data
• daily quality assurance reports
• change orders
• correspondence on the installation
• manufacturer or contractor warranties
• documentation of roof inspections or evaluations, including photos
• documentation of changes made to the roof or new equipment installed.

Historical file information assists in diagnosing conditions observed during roof surveys and facilitates accurate and complete development of repairs.

Roof surveys
Roof surveys should be performed by a competent person at least twice a year, in the spring and fall.  During the spring survey, you can observe any winter damage, and crews can make repairs during favorable weather.  Fall surveys allow you to identify and repair the roof before weather turns colder.  Also, schedule additional surveys after major storms or construction activities.  Combine moisture surveys with visual surveys when you suspect moisture infiltration.  During the survey:

• check roof components
• identify deficiencies requiring corrective action
• develop long-range preventive maintenance needs
• discuss observed conditions that may impact the long-term performance of the roof system.

Survey documentation should consist of a written report, photographs and notes on a roof plan that indicate conditions observed.  The roof plan should supply sufficient data to facilitate performance of the required repairs.  Several checklists are available for documenting conditions observed during a survey.  These checklists, however, often fall short of conveying true condition assessment over the long term.

Corrective action
Once you obtain survey information, implement corrective activities.  These activities can be accomplished by in-house personnel, roofing contractors or both, depending on the quantity and types of action required and technical abilities of in-house personnel.  Generally, minor repairs can be accomplished using industry-standard repair procedures.  This eliminates the need for lengthy repair specifications.  If repairs are major, however, or are required on several areas, develop detailed plans and specifications to aid in obtaining competitive pricing.

Frequency
The frequency of various tasks associated with a roof PM program depends on the roof's age and condition, environmental influences, roof-top traffic, occupancy sensitivity, size and roof accessibility.  The following guidelines can help determine the frequency of the tasks:

• Perform comprehensive visual roof surveys semi-annually.  For large roof areas in good condition with limited roof-top traffic, however, perform a comprehensive survey in the spring.  Do limited overview surveys in the fall to ensure integrity prior to winter weather.
• Conduct warranty surveys before the contractor or manufacturer's warranty expires.  This allows the repair of any deficiency covered, before the expiration of possible monetary obligation.
• Perform housekeeping surveys on most roof areas monthly.  These surveys help to identify potential problems.  You might need to increase the frequency of these surveys.  For example, roofs adjacent to trees may require that crews remove vegetation from drains weekly during the fall.
• Schedule corrective steps or repairs reasonably soon after the survey.  Delaying corrective action can allow small, isolated deficiencies to become major problems that can be expensive and difficult to repair.
• Conduct roof moisture surveys on three-year cycles unless specific conditions exist that warrant more frequent surveys or you suspect moisture in the roof system.  Perform the first or base-line survey before the contractor's warranty expires so that repairs are covered under the terms of the warranty.  In any case, the first roof moisture survey should be performed within two-three years of installation. 

Non-invasive moisture testing technologies--infrared thermography, electric capacitance and nuclear detection--allow an inspector to test for moisture in roof materials without having to cut into or otherwise create penetrations in the roof.  Here's a brief description of each system:

• Electrical capacitance--an electric capacitance meter placed atop a roof creates an electrical field in the top few inches of a roof.  If water is present, the dielectric properties of the roof change, causing the meter reading to increase.
• Nuclear detection--A nuclear meter indirectly reads moisture by emitting neurons from a radioactive source into the roof.  Hydrogen atoms in the roof slow down the neurons, and a counter in the unit reads the backscatter.  Since water contains hydrogen, areas of wet insulation generate higher readings, causing the unit to sound.
• Infrared thermography--Infrared scanning detects moisture-laden insulation by reading differences in surface temperatures of wet and dry insulation.  Wet areas show up brighter, or hotter, through the system's camera.

Staffing
The person performing visual roof surveys should be very familiar with the design, installation, repair and types of failure for roof systems surveyed.  Whether surveys are done by in-house staff of contracted to a consultant depends on the technical competence and availability of your resources.  In-house personnel who've had training in roof inspection, diagnosis and repair can perform limited overview surveys, such as those done in the fall.

Consider assigning housekeeping surveys to mechanics responsible for daily building PM duties.  In most cases, you can include the housekeeping survey on a computer-generated work order system so it becomes an integral part of the building PM schedule.

Staffing requirements for roof repairs depend on many of these same technical and availability issues.  Housekeeping and minor PM activities usually can be performed with in-house personnel.  Specialized or extensive repairs, however, as well as roofs covered by an active warranty, generally are contracted to roofing professionals.

Performance benefits
Longer service and fewer leaks are the primary performance benefits of an established roof PM program.  Secondary benefits include minimizing or reducing:

• costly emergency or crisis repairs
• product damage
• building structural damage, including framing and exterior finishes
• interior finish damage, including walls, floors and ceilings
• occupancy downtime and disgruntled occupants.

For more on the cost side of a PM program, see the accompanying article, "The Cost of Roofing PM," on page 34.

An overlooked benefit of a PM program is found within most roofing manufacturer's labor and material warranties.  A common warranty provision is that they can be voided if an owner fails to perform regular inspections, repairs and routine maintenance in a timely manner.  As a result, proper PM helps facilities meet warranty requirements.  A roofing PM program might not be the whole answer to a maintenance manager's dream of ensuring a leak-free roofing system.  Such attention to leak detection and prevention, however, is sure to help maintenance managers and roof maintenance crews sleep easier.

The Cost of Roofing PM

The cost to establish a preventive maintenance (PM) program depends on the amount of roof area, the type of facility and the number of activities done by the in-house employees and outside contractors.  For example, in setting up a program on a new roof of average size, maintenance costs generally will fall in the following range:

Estimated costs don't include administrative, surveying or training costs and are provided as a representative range for comparison only.  When estimated costs are combined with roof construction costs and average roof longevity, you begin to see the cost effectiveness of a PM program.  This example assumes that the average life expectancy of a non-maintained roof will be 12-15 years and that a reasonable expectation for a maintained roof is 20 years.  We have not allowed for leak repairs that one would expect to be higher for the non-maintained system.  No increase has been included for inflation.

For an example of how a roofing PM program can actually save your facility money, see PM savings:

PM Savings