Home > Articles By Issue > Building Envelope & Exteriors > Article April 2003

Raising The Roof

By David A. Carl, Johns Manville

Roofs take more abuse than any other part of a building. Because they are out of sight-and usually out of mind-roofs can be severely damaged without anyone noticing. It is then that things begin to go wrong: a ceiling tile begins to dampen, a small puddle starts to accumulate on the floor, or merchandise or equipment gets damaged.

Leaking roof systems are one of the most frustrating concerns that facilities managers and building owners experience. By implementing an inspection, maintenance, and repair program-one aimed at achieving the full potential of a roof system's service life and resisting the many predators that attack roofs-building owners and managers can avoid costly replacements and keep facility users safe.

Why Now?

In these times of economic downturn, roof maintenance is more important than ever. While spending money on maintenance seems to contradict the idea that one must relentlessly fight costs during periods when consumer spending is down, it is important not to defer these expenses. Spending to maintain a roof asset today can prevent costly surprises in the future, which generally are more expensive than routine maintenance.

There is no such thing as a "maintenance free" roof. While a roof is one of a building's first lines of defense against the elements, it often is one of the last components to receive routine maintenance. Just like cars, roofs need regular preventive maintenance (PM). Maintenance for all roofs, regardless of the membrane type, includes regular inspection, cleaning, and repair. There are also common preventive methods, including the application of coatings to protect membranes from the elements that can also extend a roof's life.

Pay Careful Attention

Most roof manufacturers' warranties require that the roof be inspected at least semi-annually. These inspections are best completed in the spring- after the roof has been exposed to the harsh effects of winter-and in the fall-after a long hot summer. Additional inspections should be done after work crews have been on the roof, if leaks are found, or if weather conditions necessitate.

At a minimum, the following items should be checked:

1. Ensure that all drainage areas, scuppers, and drains are cleaned on a regular basis. This will allow for proper water run-off and avoid overloading the structure with ponding water.

2. Ensure that the roof membrane is not exposed to solvents, greases, oils (or other non-roofing-related petroleum products), or other contaminants as these may adversely affect the membrane.

3. Provide protective walkways if there is regular (once a month or more) foot traffic on the roof for equipment repairs or other reasons.

4. Properly maintain all counterflashings, metal work, drains, equipment curbs and supports, and any other rooftop accessories functioning in conjunction with the membrane roofing system.

5. Contact the roof manufacturer or contractor who installed the roof, if any additional equipment is to be installed on the roof (i.e., HVAC units, TV antennas, vents, or electrical and plumbing penetrations). A roofing contractor familiar with the roof membrane system should flash these penetrations into the roof system.

6. Examine the edges of the roof. Wind damage often occurs in these areas. Materials that have been lifted by the wind will need to be repaired.

7. Caution all trades servicing roof equipment that the roof is guaranteed and work should be carried out accordingly.

8. Restrict access to the roof. Do not use the roof area as a work or storage area, as this increases the potential for membrane punctures and other damage.

9. All pitch pans and exposed mastics are identified as maintenance items and should be replenished as needed.

In addition, several other non-roof related building envelope components can allow water infiltration either into the building and/or into the roofing system. It is important that those components also receive the same amount of attention. Costly damage to the roofing system can occur as a result of water infiltration from sources such as HVAC units, walls above the base flashing, copings, and other roof penetrations.

Categorically Speaking

There are three main types of roof repairs: emergency, temporary, and permanent. Because permanent repairs are intended to last the remaining life of the roof (and should be up to the task if they are done right the first time), they are the most cost effective and should be implemented if possible. However, if roof replacement is planned for the near future, it may be financially prudent to make only temporary repairs. Because of the variety of repair materials available, it is important to consult a roofing professional or the roofing system manufacturer for recommendations.

While many facilities have personnel on staff who are sufficiently familiar with the roof to conduct inspections and minor repairs, it is recommended that facilities also contract with a roofing professional to conduct inspections, maintenance, and repairs. Roofing professionals are familiar with products and repair procedures and are equipped to make repairs using materials compatible with the existing membrane. Facilities crews not particularly adept withregards to roofing sometimes attempt repairs to the membrane using products or materials that are not compatible with it. This can cause further leaks and a more expensive permanent repair later on.

Consequences Of Actions

The consequences of poor roofing maintenance can be devastating. The following are examples of how severe the problem can become:

• A metal deck is so severely rusted that the roof system is the only thing holding together the structural integrity of the building;
• Mold growth is so extensive that abatement and health concerns are created; (for more on mold, see FM Issue on page xx of this issue.)
• A roof is so saturated by moisture that its designed weight of 10 pounds per square foot is exceed by 30 pounds; and
• Base flashing is so deteriorated that structural steel has to be replaced before the roof can be replaced.

The best way to measure the effectiveness of PM is to consider life cycle costs. These costs include maintenance, cost of damage due to leaks, lost energy due to wet insulation, insurance premiums, and all other costs associated with the roof. These costs can quickly add up if a roofing membrane is not properly maintained. For help in conducting a life cycle cost analysis, examine ASTM Standard E-917: Standard Practice Of Measuring Life Cycle Costs Of Buildings And Building Systems.

Depending on the size of the roof and the membrane system installed, if not properly maintained, a roof asset could end up costing a company a great deal of money. In order to protect this asset, it is important to begin a regular maintenance and repair program. Any flaw in a roof, if left unattended, can inflate the original repair cost in terms of interior damage, wet insulation, escalated energy costs, and other maladies. So be smart. Start an inspection plan today and make roof repairs in a timely and informed manner.

Carl is the manager of the Guarantee Services Unit for the Denver, CO-based Johns Manville Roofing Systems Group. For more information, call (800) 922-5922 or visit the Internet at www.jm.com. Was this article helpful?

Do you have a PM program in place to help nurture your membrane into its golden years? Send comments via e-mail to jkorot@groupc.com.