The First Facility Management Blog

The Ice-Away Snow Melt mat from Cozy Products is designed to protect against slip-and-fall accidents and workman’s compensation claims. Its heavy duty construction consists of an electric heating element sandwiched between two protective surfaces of non-slip rubber.

Ice-Away Snow Melt Mat from Cozy Products

The mat should be placed on dry ground, and once it’s plugged in, it begins to melt snow and keeps the surface free of ice. Applications include entrances, ramps and handicap accessible structures, loading docks, hospitals, nursing homes, hotels, schools, churches and synagogues, and residences.

Using 40 watts per square foot (mats are 2′x3′), the Ice-Away Snow Melt mat costs less than embedded systems and is portable. Plugs into any standard 110V outlet and melts up to two inches of accumulated snow in less then one hour.

Equipped with a 15′ power cord that plugs into standard outlets using its own Equipment Leakage Circuit Interrupter (ELCI). 
Designed to be left outside for the entire winter season, each mat is built and tested according to the IEEE 515.1 electrical standard.

The U.S. Environmental Protection Agency (EPA) has proposed a new rule that would make deicing practices on aircraft and at airport runways more environmentally friendly while maintaining operational safety. Discharges from deicing operations at airports can have major impacts on water quality, causing reductions in wildlife, contamination of drinking water sources, and impacts in residential areas and parkland. EPA is proposing requirements for control of the wastewater associated with the deicing of aircraft and pavement at more than 200 commercial airports.

EPA estimates that six major airports, which are among the largest users of aircraft deicing fluid, would likely install centralized deicing pads to comply with the proposed requirements. Airports using lesser amounts of deicing fluid would collect 20% of the spent fluid with technologies such as glycol recovery vehicles. The estimated 50 airports that currently use urea to deice runways would use more environmentally friendly deicers, or reduce the discharges of ammonia from continued use of urea. A number of airports in the country already comply with the proposed requirements.

EPA and states would incorporate the proposed requirements into stormwater permits. The EPA has worked closely with the Federal Aviation Administration which has determined that, if implemented, this regulation would have no impact on the safe operation of airplanes or runways that are treated for snow and/or icing conditions.

EPA is proposing technology-based effluent standards for discharges from airport deicing operations. The requirements generally would apply to wastewater associated with the deicing of aircraft and airfield pavement at primary commercial airports. Airports that conduct aircraft deicing operations, have 1,000 or more annual jet departures, and 10,000 or more total annual departures, would be required to collect spent aircraft deicing fluid and treat the wastewater. These facilities could either treat the wastewater on-site or send it to an off-site treatment contractor or publicly owned treatment works. Some airports would be required to reduce the amount of ammonia discharged from urea-based airfield pavement deicers or use more environmentally friendly airfield deicers that do not contain urea.

The Administrator signed the following notice on August 17, 2009, and EPA is submitting it for publication in the Federal Register.

The proposed rule is open for public comment for 120 days following publication in the Federal Register.

More information on the airport deicing proposed rule: http://www.epa.gov/guide/airport/

The Institute for Business & Home Safety is offering the following information and engineering guidelines that can help prevent this threat to life safety and property. Emergency managers in a number of states are warning facility managers to pay attention to the accumulation of ice and snow on their buildings.

The age of the building is a major factor in the snow load risk.

• Newer building codes provide much better guidance for estimating snow loads, particularly the increased loads near changes in roof elevations where snow drifts and snow falling from the upper roof can build up on the lower roof near the step.
• Older roofs can also suffer from corrosion of members and connections which can reduce its ability to resist high snow loads.
• Buildings with light weight roofs, such as metal buildings or built up roofs on bar joists generally provide less protection from overload than heavy roofs.

The safety margins used by engineers are based on a combination of the weight of the roof and the snow loads. Consequently, there is usually a larger margin of safety against excess snow loads for heavy roofs than for light weight roofs.

• For flat roofs, the step-down area between roof sections is particularly susceptible to roof overload because of the tendency for ice and snow collection, especially during periods of windy weather.
• Roof top equipment and roof projections, such as mechanical equipment, which is over 2′ tall causes snow accumulation due to drift, creating the need for higher snow load consideration in these areas.

-An even more serious condition can be created when a taller building or a taller addition is built adjacent to an existing building.

-Unless, the existing building is strengthened in the area next to the new taller building or addition, snow accumulation on the lower roof near the step could produce much higher loads than those considered by the original designer for the existing building.

The design plan is the best source for determining how much snow load a building can handle. These designs can range from a snow load of 10 to 20 lbs per square foot in Mid-Atlantic states, to between 40 and 70 lbs per square foot in New England.

IBHS offers these general guidelines to help estimate the weight of snow:

• Fresh snow: 10-12 inches of new snow is equal to one inch of water, or about 5 lbs per square foot of roof space, so you could have up to 4 feet of new snow before you need to worry.
• Packed snow: 3-5 inches of old snow is equal to one inch of water, or about 5 lbs per square foot of roof space, so anything more than 2 feet of old snow could be dangerous.
• The total accumulated weight of two feet of old snow and two feet of new snow could be as high as 60 lbs per square foot of roof space, which is getting toward the design limits of even the best designed roof.
• If there’s ice, it’s much heavier, with one inch equaling about a foot of fresh snow.

Lastly, IBHS advises, for safe removal that won’t endanger you or damage your roof, consult a roofing contractor.

Lawrence E. Keenan, AIA, PE, director of engineering with Hoffmann Architects, an architecture and engineering firm specializing in the rehabilitation of building exteriors, discusses winter deicing options.

Evaluating Deicing Options

Lower Supply, Higher Costs
With winter weather upon us in many areas, building owners and managers face another season of snow removal and ice melting. With the high liability of slippery surfaces, maintaining safe sidewalks, plazas, and parking areas is a must. But reports of salt shortages and higher prices may mean reassessing available options this season to meet operating budgets. While rock salt or calcium chloride might suffice to get the job done, the expense of repairing damage from these corrosive chemicals often justifies the costs of premium products and alternative methods. In addition to economic factors, each facility’s climate, usage, location, construction type, and exposure will dictate the appropriate deicing strategy.

Some deicing salts can be damaging to building materials.

Comparing Deicing Options
When planning for winter, building owners and managers have a number of options from which to choose, each with benefits and drawbacks. Because there is no one product that meets all needs, a combination of materials, incorporated into a comprehensive snow and ice removal program, is the best approach to meeting cold weather demands (see chart below).

Common Deicing Chemicals

The most commonly used deicing chemicals include sodium chloride (rock salt) and calcium chloride. Rock salt, historically the cheapest option, is the deicing standard used by transportation departments for roadways. However, sodium chloride is extremely corrosive to steel and destructive to masonry and concrete. Because of its low cost, rock salt has retained its popularity in spite of these properties, but this year’s high salt prices may mean that savings is insufficient to justify subjecting building materials to such a caustic chemical. Calcium chloride, while more expensive, is the most effective deicing chemical; it is the benchmark by which other compounds are measured. While calcium chloride can have the same detrimental effects as rock salt, these tend to be much less severe. In an effort to avoid these damaging properties, other chemicals have been developed, but they may not be as effective, particularly at lower temperatures.

Snow and ice removal carries liability issues.

In addition, there are many proprietary products available, which claim to correct the deficiencies of any one compound. These products usually combine various deicing chemicals, sometimes alongside other performance-improving agents, such as corrosion inhibitors or traction enhancers (e.g. corn starch). While proprietary blends pledge greater effectiveness than their simpler counterparts, they also come at a higher price.

Ice Melting Or Ice Loosening?
For the purpose of this discussion, it is important to differentiate between ice melting chemicals and ice loosening chemicals. Ice melting chemicals remove ice by transforming it into water, which flows away; the chemical is typically washed away with the melting ice, requiring frequent reapplication. Ice loosening chemicals, by contrast, do not melt snow or ice, but rather create a slurry at the surface that interferes with the bond of the ice to the pavement, aiding mechanical removal. Ice loosening chemicals work best if applied before it snows, and they typically last longer than ice melting chemicals.

Our Picks
The chemical that is most sympathetic to existing structures—and most highly recommended—is CMA; however, CMA does not work at lower temperatures, must be applied before snowfall, and demands expeditious, and, often, continuous snow removal. Should an ice melting chemical be required, opt for potassium chloride, magnesium chloride, or a blend of the two, but not outside their operating temperature range. For colder, more severe conditions, it may be necessary to use calcium chloride or a proprietary blended material to maintain safety. In all cases, application of grit/sand greatly increases traction and diminishes the amount of deicing chemical required.

As the days turn colder, building owners and managers should consider snow removal options—before the first big snowfall forces last-minute decisions. Ideally, proposed materials should be pilot tested to verify suitability and performance, then integrated into a multi-faceted snow and ice removal strategy. A design professional experienced in exterior maintenance planning can assist in evaluating deicing needs and making informed choices.

Keenan, AIA, PE, director, engineering with Hoffmann Architects, has specialized experience in parking structure, plaza, and building exterior rehabilitation, including investigation, repair, and surface treatment consultation. Founded in 1977, Hoffmann Architects, Inc., specializes in the rehabilitation of the building envelope. The firm has offices in Hamden, CT; New York City; and Arlington, VA.