As this column was prepared, the Weather Channel was tracking a major snowstorm moving up the East Coast. Weather predictions like these are far more accurate today than they were just a few years ago, but our preparations for dealing with major weather events often aren’t taking advantage of those extra few hours or days.
If a major storm is headed your way, use the extra time to make a contingency plan for your roof delineating necessary responsibilities before, during, and after the storm. When bad weather hits, you’ll be glad you did.
Set up a meeting with your chief of maintenance or general contractor and other trades to address several issues. Identify the critical parts of the building, such as boiler rooms, computer rooms, and electrical installations. Assign a priority to get to those areas and, when needed, restore or protect them first. Be sure to account for these areas as well so you’re not scrambling during the storm:
- Ensure access to snow blowers, fuel for power tools and shovel storage.
- Confirm that roof drains and scuppers have been tested and properly hooked up to the storm sewers. Roof drains should be set into a sump (depressed area with thinner insulation) so that heat from the building will melt ice and snow at the drain first. Install tell-tails to help locate rooftop drains, vents and HVAC units so that snow blowers do not cause damage during the snow removal process.
- Discuss how to access snow blowers, shovels, sandbags and other safety equipment where needed. Safety considerations like gloves, boots, helmets, and eye protection should be stored in an easily accessible area where they can be quickly employed as needed. Frostbite is no laughing matter.
- Pails of asphalt mastic should be available, along with work gloves and trowels. These are generally available at big box centers but may be sold out during major events, especially those that can cause wind damage. (Pruning large tree branches will help avoid the associated window breakage.)
- Protect emergency power. Before the storm hits, test your backup power sources and make sure key personnel are trained to operate them.
- Don’t forget communication. Landlines and cell phones may be unreliable during a major event. Employees will be concerned with the safety of their families, so back-up phone numbers should be available as needed.
DURING THE STORM
Use traffic cones to keep pedestrians and their vehicles away from areas where snow will be dumped. Generally, no one should be traipsing around on a roof in bad weather. Single-ply membrane roofs can be very slippery when wet and will be slow to melt ice compared to a dark-colored bituminous roof. Roof-mounted photovoltaic panels may mean there are only narrow paths to navigate, and the possibility of falling is increased. If solar panels are on your roof, establish how to remove drifted snow without damaging the panels.
If deflection of the roof deck is observed from extreme water or snow accumulation, it may be necessary to evacuate the building and to notify emergency services.
HVAC maintenance or repair of rooftop equipment may take on an urgent nature if it affects building operations. However, wind damage or falling ice may result in electrical hazards. Proper insulated boots, helmets, and gloves should be on hand for the emergency crews.
In an extreme blizzard, drifting snow or frozen roof drains may be cause for concern about roof collapse. If emergency crews are attempting to remove snow or ice, they should use plastic shovels rather than metallic ones to avoid dinging the roof membrane.
Some thermoplastic roof membranes (PVC or TPO) can be heat welded to repair membrane damage. However, the heat welders require electricity, and wet, powered cables can be a hazard. (A trained roofing crew will bring their own electrical generators, properly grounded.) A building manager may be better off to make emergency patches with asphalt mastic or peel-and-stick membrane, even though the mastic will contaminate the patch areas and will need to be cut out and replaced when the weather improves.
Torching grade polymer-modified bitumen (MB) can be used to patch BUR as well as MB membranes. (In a pinch, they could also be used on rubber and plastic membranes.) However, there are fire risks, both from the torching and storage of propane gas. A wise building owner would send critical personnel to a Certified Torch Applicator Training Program (CERTA) offered by NRCA or MRCA if this kind of repair is planned.
Locating active roof leaks is very difficult on ballasted (or vegetated) roofs. The common moisture detection devices (nuclear, capacitance, infrared, and vector) are difficult or ineffective with ballasted EPDM, so it is worth the effort to use thicker membranes (i.e. 60 mils instead of 45 mils for greater puncture resistance) as well as stone mat with these ballasted roofs. It is highly recommended that the roof be flood-tested before the ballast is installed.
One final word: Keep the drains and scuppers clear of debris!
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How to Patch TPO
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