General Roofing Systems Canada removes snow and ice throughout Canada. Flat Roof Repair; Calgary, Red Deer, Edmonton, Fort McMurray, Lloydminster, Saskatoon, Regina, Medicine Hat, Lethbridge, Canmore, Banff, Cranbrook, Kelowna, Vancouver, Whistler, Winnipeg, Toronto and points between. British Columbia. Alberta. Saskatchewan. Manitoba. Ontario.
CAUTION: DO NOT REMOVE SNOW FROM THE ROOF YOURSELF!
GRS Canada, Inc. has removed snow and ice from hundreds of residential, commercial, and industrial rooftops throughout Alberta, BC, and Saskatchewan.
We have also consulted facility managers at commercial and industrial facilities all over the world on proper snow removal protocols, techniques, and adherence to structural engineering. Live loads on rooftops are important to consider, proer safety for the workers on a roof is critical, and knowing how to remove snow from a roof may just save the lives of the workers and occupants in the building.
Our article on rooftop safety and roof snow removal was spurred by the roof collapse in Anchorage, Alaska and the subsequent news reports talking about “roof snow removal parties”. Our concern is that folks think it is OK to remove snow from roofs without using professional providers.
MUNICIPALITY OF ANCHORAGE ISSUES PRESS RELEASE MARCH 2, 2012
“ANCHORAGE– In the last few weeks several roofs in Anchorage have failed due
to stress from snow. The buildings involved were generally older (pre-1980) with
flat roofs. Several, but not all, failed where snow had drifted.
Newly fallen snow is not very dense. However, over the course of the winter
accumulated snow on roofs becomes denser. Per current code the design snow
load in Anchorage is 40 pounds per square foot (psf), which is equivalent to
approximately two feet of dense snow. A roof designed to current code should
not have problems until the load is significantly higher than 40 psf.
It is recommended that building owners and managers monitor the snow loads
on their roofs. Of special concern are older buildings with flat roofs, and those
with areas of snow drifting, such as at parapets and lower roofs. Special
attention should also be paid to long overhangs where snow blankets are draping
over the roof edge.
If one hears creaking in the roof, observes excess deflection in trusses or beams,
or sees bowing of columns, immediate investigation by a structural engineer is
Conditions on roofs may worsen as additional snow falls in March and April,
building owners should consider preventative roof shoveling. Shoveling a roof is
inherently dangerous, so special precautions should be taken. The intent is to
lighten the roof load by removing a significant portion of the snow, not
necessarily all of it. Trying to remove all of the snow down to the roofing could
increase the danger of a shoveler sliding off the roof as well as causing damage
to the roofing materials.”
DO NOT REMOVE THE SNOW FROM YOUR ROOF YOURSELF – ROOFS COLLAPSE.
Firefighters responded to a callers reporting structural collapse at the South Anchorage church Friday March 2, 2012. Firefighters initially were called with reports of a fire at the Abbott Loop Community Church at 2626 Abbott Rd. shortly after 6 p.m. Callers reported smoke, including one caller reporting an explosion.
ROOF SNOW REMOVAL PROTOCOLS AND CONSIDERATIONS
How much snow is too much?
Live loads are an important consideration when assessing rooftop snow and possible removal. You need to know how much snow and ice rooftaps can hold safely, what the effects are of ice buildup on roof systems, and how to properly remove the snow so that the building does not become structurally unsound and collapse while you are removing the snow.
Generally speaking – and depending on where you live – most flat roof systems are constructed to safely hold a maximum of 15 to 20 cm or ice or 35 to 40 cm of hard pack snow (70 to 80 cm of fresh snow).
There are many other considerations such as the engineering and age of teh building, or how often the roof can withstand the snow loads.
In Alberta, building codes (as of 2006) require roofs to withstand about 40 lb. of snow per square foot once every 50 years. In this fashion, one can predicate how much their building can withstand every x years.
If the snow load on your roof is getting close to the calculations above, you need to have the snow removed from your roof.
Time is also important when considering roof load capacity – this is called the fatigue factor.
Roof collapse can occur on roof systems that have half or less of the live load described above.
Measuring Roof Snow Loads
A “safe” amount of snow or ice on a roof is none at all. Removing the snow will mitigate ice damming, which will keep the roof membrane in a good condition. Regular removal will also keep the roof drains working properly.
When the ice and snow starts melting in the spring, be sure a knowledgeable roofing contractor or a trained maintenance person is regularly checking the roof drains or scuppers to ensure that the water is flowing down the drains, as opposed to filling your flat roof up like a pond.
If you are still convinced that you can remove the snow and ice from the roof yourself, please refer to our blog article here. We provide safety considerations as well as a “how-to” guide.
IN THE PRESS…
From the Edmonton Sun Newspaper:
“General Roofing Systems advises that the snow isn’t as much
of the problem as is the ice build-up underneath. Snow melts, it freezes and then is covered by a new layer of snow. The process repeats until the ice sheet becomes too heavy for the roof to bear. Trouble may not show up until the spring thaw when water that ended up freezing in the attic melts and comes through the ceiling. Then, of course there is the possibility that all that weight will
cause structural failure.”
24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. firstname.lastname@example.org.
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