How to Keep Your Roof Leak-Free
For too many FMs, roofs are a prime example of “out of sight, out of mind.” But maintenance is vitally important if you want to keep the rest of your building in good shape. Don’t make emergency spending for roof repairs a habit. Use your budget wisely and perform inspections and preventive repairs to avoid big expenditures.
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Get a handle on roof maintenance with this guide to keeping your roof in good health.
Why Maintenance Matters
Regular roof inspection and maintenance helps you save money, time and headaches in four ways:
1) More time between replacements. The biggest reason to maintain your roof is that it extends the roof’s life, which offers multiple advantages. Roof technologies have improved considerably over the last few decades, so it’s not unreasonable to expect a lifetime of at least 20 years from a properly installed and maintained roof. Without maintenance, the expected lifetime is more like 10-15 years – and if you’re planning to occupy your building longer than that, the cost of re-covering or replacing your roof 5-10 years early will add up quickly.
2) Avoid structural damage. Roof leaks lead to rusted steel or rotting wood that can compromise your facility’s structural integrity, requiring a costly fix.
3) Preserve your building’s interior. The contents of your building are probably worth more than the cost of a roof repair. What happens if water drips on a computer or server rack in your facility and it shorts out? How much data could you lose? Material damage and the cost of lost opportunities can both be avoided by keeping your roof leak-free with maintenance.
4) Reduced hassle and liability. When water comes in, the typical solution is to put out trash cans to catch the drips. But containers clog hallways, and in a retail setting, they present an extra obstacle for shoppers. Overflow or drips that have missed the trash can create a slippery surface that increases the risk of personal injury, which could result in a costly lawsuit if someone slips in the puddle and gets hurt.
A lack of leaks also means fewer leak calls, making your life easier and allowing you to budget for planned roof maintenance instead of wasting money responding to emergencies.
Design a Real Maintenance Program
Too many FMs rely on a “fix things when they break” mentality, which isn’t a maintenance program at all. Preventive maintenance programs are a step up as their aim is to discover problems before they cause failures and fix them early.
But for the best possible results, institute a roof asset management (RAM) program, which combines preventive maintenance and inspections with corrective action to keep the same problem from recurring.
For example, you might realize your roof has seen quite a few leaks around your HVAC equipment from foot traffic and mechanics dropping tools. You would catch the damage during a regular inspection and fix it before it caused a major failure, but you also might put down some walk pads in the affected area to prevent future damage.
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RAM programs also incorporate planning for future re-roofing and replacement – you might plan to get 25 years out of your new roof, so you would start budgeting for a replacement 25 years in the future. If the roof is still sound after 25 years, you obviously don’t have to replace it right away, but in the meantime you’ve already started to develop funding.
This is vital – roofs can cost $10 to $20 per square foot, and when you measure the size of your roof, the total cost can be shocking. Replacing a 10,000-square-foot roof could run $100,000 or more.
Planning ahead to replace the roof helps spread out the expenses and ensures that you can afford the replacement when you need it. Sometimes during snowy seasons, contractors will offer good rates on roofing work just to keep their crews busy and maintain a cash flow into their business, so if you’re able to plan for this well ahead of time, you can take advantage of better prices.
PHOTOS COURTESY OF Ted Michelsen
To start incorporating a RAM strategy, you first need to make sure your roof is maintainable – see “8 Elements of a Maintainable Roof” to determine whether your roof fits into this category. Next, make sure your crew is up to date on training and development. Anyone who works on the roof needs to have a basic understanding of roof materials and technologies.
After everyone is up to speed, conduct an initial roof assessment. This involves a detailed measurement of the roof – not just the perimeter, but also the locations of all penetrations, drains, rooftop equipment and anything else installed on the roof.
Take at least two or three people with you – the first assessment takes two to five times as long as a normal inspection (though some of this time will be spent in your office putting together a roofing diagram and organizing the collected information) and it’s difficult to get accurate measurements with only one person. The assessment results will be valuable later.
The other advantage of this assessment is that it can help you flesh out information that might be missing from your roofing records. Take notes on the types of flashing, membranes and other components you find while conducting your assessment. Also mark any repairs you discover – they are potential sources of leaks.
Based on the information from the initial inspection, you can then start planning a repair project to fix any obvious defects you found on the roof.
As the repairs are completed, keep track of what was fixed and when in your records. Refer back to this documentation whenever you do your regular inspections, which should be taken care of at least twice a year – as a rule of thumb, inspect your roof when the ducks fly south and again when they fly north. Newly installed roofs might need additional inspections – check your warranty to see how often the manufacturer requires you to inspect the roof.
Also inspect after any major storm or whenever someone has accessed the roof to repair equipment – that way you can catch any damage right after it occurs and stop it from getting out of control. If you find a leak, repair it immediately.
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Other low-priority repairs, like seams that are just starting to open up, may be able to wait a few months. The lowest priority repairs are issues that aren’t leaking at all, such as patches or ponded water that hasn’t gotten into your building yet. Keep an eye on them during regular inspections.
Inspect for Common Issues
During your inspection, don’t just look for existing problems – watch for common conditions that can afflict any roof type. Debris left on the roof can potentially cause damage – for example, nails left on a ballasted single-ply roof can easily puncture the roof membrane. Save yourself the trouble of trying to find a small tear and keep junk from collecting in the first place.
Flashing defects occur in areas that see a high level of differential motion between the roof and building. This movement changes directions, adding stress to the flashings. It’s not uncommon for even a properly designed roof to have flashing issues, and the problem is multiplied if the design isn’t ideal.
A common problem I see is that many designers bond metal, which moves a lot, to a roof membrane that either does not move much or the movement stresses the adhesive so much that it fails.
Bad details, such as poorly installed drains, joints or penetrations, aren’t flexible enough and keep the roof from moving. This means the cycle of expansion and contraction won’t work properly, creating a failure.
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Roof owners often overlook that temporary repairs are temporary regardless of roof type. Putting down duct tape or spreading some roof mastic can be great in a pinch to stop water from coming in, but a “temporary” repair should be just that – and it should be replaced with a permanent repair as soon as possible. That requires you to remove any wet or damaged materials and restore the affected spot to the same condition as the rest of the roof.
For example, a roof with a 90-mil single ply membrane needs a 90-mil patch, not a temporary fix with a membrane that’s thin and crackable, and it must be adhered with materials designed to be used with your roof type. If you rely on temporary patches, you’ll keep fixing the same problem over and over again.
Know Your Specific Roof Risks
Depending on your roof type, your building may also be vulnerable to problems that plague certain materials. With built-up roofing, you may run into blisters, which are built in during construction when the contractor doesn’t ensure a solid film of bitumen between the plies, thus allowing air pockets to grow.
The industry recommendation is not to repair blisters – they’re difficult to fix and an improper repair can leave you with multiple blisters instead of one. Keep people from walking on the blister, then fix the damage whenever it finally opens and breaks. The membrane under the blisters will still offer some protection when this happens, which will give you time to get someone on the roof to repair the failed area around the blister.
Built-up roofs can also suffer from displaced or damaged surfacing. The surfacing is there to protect the waterproofing bitumen, so if strong winds are scouring off that protection, weathering will damage the waterproofing material and shorten the life of the roof. Fix this as quickly as possible, even if that only entails putting some roof mastic and gravel back on it until you can secure a lasting repair.
Blisters can also affect modified bitumen, particularly older roofs utilizing SBS sheets in hot asphalt. Before 2004, the asphalt typically wasn’t hot enough to create proper bonding between the modified bitumen and the lower plies. Industry recommendations for the proper asphalt temperature have since eliminated the problem, but if your roof dates earlier than 2004, keep an eye out for blistering.
Also watch for exposed modified membranes, which can fail in as few as five years if you live in a high-UV area. A coating can save your membrane if you catch the problem early enough, but when it’s badly degraded, the only solution is a new membrane.
One of the biggest issues with single-ply roofs is open seams, so when you’re inspecting your roof, look carefully at all the seams. This type of roof has no redundancy, so if the roof fails, water has a direct path into your building. Single-ply sheets also tend to be thin, so dragging equipment or tools across the roof creates a split that allows water infiltration.
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Over time, you may spot raised fasteners on a single-ply roof. Fasteners are not typically set soundly or tightly, so building movement tends to cause the fasteners to back out and raise up. Excessive foot traffic can also lead to fastener trouble because it compresses the membrane and raises the load on the area with the fastener, which can then tear a hole in the membrane. When this happens, cut an X in the affected area, re-seat the fastener and put a patch on top.
Raised fasteners can also affect metal roofs, though for different reasons. Fastened roof systems, such as structural metal roofs, pair fasteners with rubber gaskets. A fastener that isn’t fully seated into its gasket can allow water into the building. If the threading on the fastener is stripped, simply buy a larger diameter fastener and seat it properly.
Corrosion is another concern for metal roofs. Copper coils in rooftop HVAC units produce condensate that contains both copper ions and acids, both of which will damage the zinc-based protective coatings on metal roofs and lead to rapid rusting. The damage can be catastrophic if you don’t catch it early enough.
To prevent this from happening, duct the condensating water to keep it from running across the membrane. If you’re already noticing damage to the steel, look into new coatings to protect it from further deterioration.
In the meantime, invest in the Repair Manual for Low-Slope Membrane Roof Systems if you don’t already have it. This comprehensive repair manual is available from NRCA, ARMA and SPRI and will walk you through long-term repairs for all of the major membrane types. You can even include it in your bid requests – copy the pages with the repairs for the work you need done to ensure everyone who bids on your work is doing the same industry-approved procedures.
With a well-planned roofing maintenance program and proven repair procedures, you can maximize the life of your roof and keep your building in the best shape for years to come.
Ted Michelsen is the president of Michelsen Technologies, LLC. He is a roofing educator who has worked with the Roofing Industry Educational Institute and the Better Understanding of Roofing Systems Institute. His extensive background in roofing products includes 26 years at Johns Mansville, where he served as vice president for technical services and research in the roof systems division. *Photos courtesy of Ted Michelsen
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