Winter weather can be a hassle for even the most prepared plants

How to save your roof when Old Man Winter makes a surprise attack

By Sheila Kennedy

You thought you were ready for winter. Your roof is well ventilated and the drains are clear. Leaks have been patched and defects repaired. Insulation is adequate and intact, and you added a vapor retarder to keep moisture from condensing on the underside of the roof deck. But this winter's weather is unusual, and you’re experiencing excessive snow accumulation, ice dams and leaks after all. Now what will you do?

Consider outside expertise: Ice and snow removal is best left to trained, licensed roofing professionals because of the inherent risks involved – risks to life and safety and the risk of damage to the roof surface. Your contractor should be familiar with the products and procedures recommended by your roof manufacturer, including those specific to cold and wet conditions. Following are some of the techniques either you or they may employ.

Melt ice and snow: Ice dams can expose the roof to leaks. Making a channel in the dam will allow the trapped water to drain off the roof, but ice scrapers can accidentally damage the membrane. In warmer temperatures, tap water will form a channel less intrusively than other means.

Chemical deicers should be used sparingly and following the manufacturer’s directions. The use of certain chemicals could void your roof warranty, but safe ice- and snow-control products are available in pellet, liquid and aerosol spray forms. Rock salt and calcium chloride are not ideal for roofs.

Another option is lining the roof, gutters or downspouts with heaters. Heating cables conserve energy by automatically adjusting the heat output to match ambient conditions. Snow and ice sensors and melting controls can automatically activate and deactivate heaters based on weather-driven thresholds.

Remove snow: Heavy, wet snow, sleet and freezing rain can burden the roof structure. Determine the safe snow depth for the roof based on the building design and structural load limits. Initiate your snow removal plan when the snow accumulates to half this depth. Do not attempt to remove all the snow – damage to the roof may result.

Snow-blowers, roof rakes, plastic snow shovels and wheelbarrows should be kept on-site in climates where accumulation is likely. Target snowdrifts first, and try to maintain an even load across the rooftop. If a snow-blower is used, set the blades high to avoid damaging the membrane, and make sure you have adequate fuel on hand. Once the snow load is reduced to safe levels, nature can take its course.

Repair leaks: Gale-force wind, hail and windborne debris can compromise the membrane. Cuts or punctures, damage to the seams and flashings, and clogged gutters can lead to leaks in the roofing system. Keep the bottom of downspouts clear so that water can drain properly. Make sure shoveled or plowed snow does not obstruct them.

If water is flowing into your roofing system, consider making a small hole in the ceiling to allow trapped water to drain out. This may prevent further ceiling damage or collapse, but make sure you have buckets ready.

Some pliable roof-patching compounds are designed for cold-weather repairs and can be applied in wet weather at temperatures as low as 25°F or even 0°F.

Handle emergencies: If conditions suddenly become extreme, pull out your tarpaulins, generators and space heaters. Protect any interior items that are in the path of leaks. Be alert for visible and audible signs of structural stress and evacuate the area immediately if conditions appear hazardous. Turn off the gas, electricity and processing systems, and enlist a structural engineer to evaluate the facility. Contact your insurance company for guidance.

Do postmortems: A thorough roof inspection should follow each major winter storm to ensure that no new defects or failures have occurred. Any temporary repair measures should be followed by permanent corrective actions as soon as possible. For example, improper roof insulation and ventilation, as well as air leaking from the interior of the building to the roof, promote reoccurrence of ice dams. Quick and effective action is crucial – it may not be long before the next winter storm strikes.

Find more information: Ask your insurance company about its loss control or risk-management guidelines pertaining to winter weather conditions.

Available for purchase from the National Roofing Contractors Association Web site is the “SPRI/NRCA Manual of Roof Inspection, Maintenance and Emergency Repair for Existing Single-Ply Roofing Systems,” and “Repair Manual for Low-Slope Membrane Roof Systems.”

If coating repairs are required, a technical bulletin titled, “Cold Weather Application Tips for Roof Coatings” is available for free from the Roof Coatings Manufacturers Association (RCMA).

Contributing Editor Sheila Kennedy is managing director of Additive Communications. E-mail her at
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