Services & Maintenance: Keeping On Top Of Leaks
By Richard L. Cook, Jr., RRC, RWC, CCS, LEED® AP
Published in the November 2010 issue of Today's Facility Manager
The roof is an important facility asset. It serves as a capstone of sorts to the building envelope, yet its importance is often overlooked—as what is out of sight is frequently out of mind. However, in a time of tighter budgets and increased emphasis on sustainability, it makes more sense than ever for facility managers (fms) to take a proactive approach to maintaining their roofs. They can hire skilled designers and contractors, use quality materials, and develop a long-term roof maintenance plan (RMP) that will positively affect their organizations’ bottom lines.
According to the National Roofing Contractors Association (NRCA) Project Pinpoint (a survey derived database intended to compile information regarding the use and performance of roof systems in the United States), while most roofs are designed for a 20 year life cycle, the average age of those replaced is 13 to 17 years. Often because of a lack of proactive maintenance, roofs are not reaching their maximum useful lives.
“In the long run, fms wind up spending more by deferring maintenance, because they will need to replace the roof sooner,” says Douglas R. Stieve, Region I Director at RCI, a professional association of building envelope consultants.
By getting organized, fms can prevent water infiltration crises and ensure the maximum value of a roof installation. The foremost consideration is the age of the roof and its maintenance history. Improper installation or deferred maintenance can result in slow leaks undetectable in the interior. ∫By the time water infiltration appears inside, structural decay can be well underway. But many roof failures, such as membrane tears, can be repaired fairly easily if caught early.
Other factors to consider in preventing water infiltration are:
- type of roof;
- prevalence of snow, ice, rain, and thunderstorms in a given climate;
- and if the membrane is exposed to sunlight and the aging effects of heat and UV radiation.
Additionally, the vast majority of water infiltration occurs through the penetrations and terminations on a roof. (A penetration is an interruption in the membrane for vent stacks, chimneys, skylights, and the like.) Examples of terminations and penetrations are parapet walls, joints, curbs, pipes, perimeters, and areas where one roof level or angle intersects with another.
Water may be forced through building members by hydrostatic pressure, water vapor gradient, capillary action, or wind driven rain. This is aggravated by porous concrete, cracks, or structural defects or by joints that are improperly designed or installed.
Any time in a roof’s lifespan is a good time to reinforce and strengthen it. Often overlooked is that fms and their staff should be involved in the design of a new roof or retrofit from the start. They will want to know, “can I change these filters?” or “what safe access means will be available?” And designers should know if the roof will create challenges for the fm.
Watch For Potential Leaks
“The most important thing is diligence—getting up and inspecting the roof,” says Thomas M. Gernetzke, RCI secretary/treasurer. Fms should have a complete inspection conducted at least twice each year—once in autumn and again in spring; they may want to do this more often if trees or foliage overhang the roof. Also, fms should visit the roof before and after any expected storms to make sure drains are not blocked, flashings are in place, and loose objects that could fly around and puncture holes in the membrane are removed.
When establishing an RMP, a well trained individual should make a thorough first inspection to establish a benchmark. Then the fm can decide who will be responsible for regular inspections. The most important thing is to have an objective, knowledgeable person visually surveying the roof on a regular basis.
If fms cannot afford to put every roof in an RMP, they can prioritize and begin with the most problematic ones. RMP tools range from a simple paper file, to manual systems using a word processor for the report, a spreadsheet for the database, and AutoCAD for the drawings, to propriety RMP software. The choice of tools depends on the organization and the types and number of roofs.
Once a benchmark has been established, it is important for fms to cover the following during routine inspections:
- Check for standing or ponding water. Is the roof getting dry as soon as possible? It should be dry at least 48 hours later when there has been no precipitation.
- Clear away debris.
- Notice the condition of the membrane. Are there any splits, punctures, damage?
- Hop on the surface. Are there any soft spots underfoot?
- Are seams and laps well adhered?
- Are flashings tight? Are drains clear?
- Are there any invasive plants that could split through the membrane?
When Water Has Infiltrated
The first step after discovering water entry is for fms to contain and catch it to mitigate interior damage. Next, the fm should look at how the water manifests itself to identify the source. If the onset is sudden or it’s at the level closest to the roof, staff should look to the most obvious first (e.g., broken sprinkler valve, broken pipe, overflowing condensate catch pan in an HVAC unit, mechanical duct door left open, or clogged drain).
Next, the roof should be inspected carefully for loose flashings, cracks, or punctures. If there is a slow, recurring leak that appears during storms, the source is likely systemic and hidden, and more expertise may be required.
Visual inspection is more difficult for systems in which the waterproofing membrane is covered with an overburden—such as soil with vegetation, ballast, or pavers. A greater emphasis in inspection and testing during construction is justified for these systems.
To find the cause of water infiltration with these and other types of situations, it may be necessary for fms to employ non-destructive testing (NDT) tools. This includes infrared imaging, nuclear, and capacitance/impedance testing methods that meet ASTM standards. NDT often needs to be employed after deferred maintenance has allowed problems to develop undetected.
Whatever action is called for, fms should document exterior conditions in their RMPs. This proves valuable should a professional roof consultant be called in, and fms should be sure to note:
- date of month and time of day;
- precipitation (amount, intensity, and duration);
- wind (direction, intensity, and duration); and
- who noticed the leak and what they were doing at the time they noticed it.
Depending on the difficulty of identifying the source of the leak, repairs can be handled in-house, with the assistance of a roofing contractor, or, after further testing and diagnosis, by a roof consultant.
Who Does The Work?
Cleaning and inspecting a new roof twice a year can be done by most in-house staff. Once a roof is five to 10 years old, the matter of who should survey it has a lot to do with the fm and the number and age of buildings being maintained. Facility management departments that employ 20 to 30 people may have the expertise in-house. Otherwise, it is worth considering a relationship with a qualified independent roof consultant trained to assess and customize the RMP, inspect membranes and flashings, and deploy NDT equipment as needed.
One issue for fms to keep in mind, according to David R. Hawn, RCI immediate past president, is the perception that roofing contractors are in the best position to identify water infiltration problems and then make repairs. Not all contractors have the expertise to solve what may be a complex problem. A contractor might notice a number of places on the roof that could be sources and repair them without getting to the deeper problem.
This is where roof consultants can be valuable. They are trained to identify the water entry conditions precisely, isolate causes, and rectify them by detailing specifically how to make the repair. A consultant can track and design a solution to the problem.
A maintenance issue unto itself, a leaky roof can impact other facility components and the operations inside. Fms who conduct regular inspections are in a better position to keep operations and budgets under control.
Cook is a principal of ADC Engineering Inc. in Hanahan, SC and is first vice president of RCI, Inc.. RCI is a professional association of roofing, exterior wall, and waterproofing consultants that developed the Registered Roof Consultant® (RRC), Registered Roof Observer® (RRO), and Registered Waterproofing Consultant® (RWC) professional designations.
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