Roof Snow Removal Considerations

General Roofing Systems Canada provides roof repairs throughout Canada. Roof Repairs are completed in the following cities: 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.

Roofing, Roof Repair – Preventative Roof Maintenance Encouraged Before Winter Comes!

Fall has arrived and winter is just around the corner. This time of year is when people tend to be the most busy, with having just came back from vacation to children starting school and various other activities. With so much on the go for people, the last thing that you want to think about is the ROOF!

Yet the reality remains, this is also the busiest time for roofers, as facility managers and homeowners alike start to prepare the buildings for the harsh weather that winter brings. This is the best time to consider whether or not your roof has any current issues that need attending to.

snow and ice damming
Ice damming across a gutter system

The snow loads in Central Alberta and Northern Alberta were record setting. For many of the roof systems, if they did not fail or have issues last winter, it is almost certain they will have problems this winter.

We have  watched several commercial and industrial roofs completely fail in the Edmonton and Red Deer areas. The roofs literally buckled under the pressure from all the weight of the snow we received. Yet we believe this could have less severe had proper maintenance been taking place before the season hit.

This  winter has proven to be highly unusual. We experience such diversities in the climates all around western Canada. For example, in Vancouver our crews were busy with torrential rain, while in Saskatoon and Regina they were busy with snow falls, and in Calgary it was a constant cycle of  freeze and thaw. All this diverse weather  kept our roofing crews at complete capacity, often having to work many hours of overtime.

Some things to consider for your commercial, industrial, and residential roof maintenance prior to the next winter setting in;

Flat Roofing: Any flat roofing that took on heavy snow loads will most definitely require some attention. We highly recommend that owners heed the warnings from the previous season and at least asses the current quality of there roof, it would be best to have this assessment completed before the first snow fall. We have an annual roof repair and maintenance check list for flat roofing and the maintenance required to be completed listed on our website.


Metal Roofing: Metal roofing was hit the hardest last winter. The reason is that metal roof systems, especially commercial and industrial, had snow loads that compromised the metal roof panel seaming. In other words, the metal panels on the roof have been warped or pressed down so hard that the seams between the panels and the fasteners are compromised. The other issue we are seeing with industrial and commercial metal roofing this year is that many of the gutter systems are damaged.

The problem with metal roof systems on industrial buildings is that when the ice builds up in the gutter it will then back up and enter the building under the metal cladding. Fortunately, there are excellent solutions for metal roof issues yet most cases do require a full replacement.

Nowadays we can coat metal roofing with liquid rubbers. This is a elastomeric spray on roof coatings that will seal the metal roof seams, fasteners, and vents.

To learn more about how to solve metal roof leak problems search the topic on our blog at the top right corner. Simply type in your inquiry and our search engine will show results of the pages to help.

In addition to this, our main web site contains several pages on metal roofing, roof coatings, and roof repairs. You can find this information listed below with  the following links:

Residential Roofs: These systems did not have nearly as many structural  failures that occurred with Industrial and Commercial roofing last year. Although that is not saying that residential roofs, roof attic ventilation and condensation did not have their fair share of complications.  The reason being is that with the snow loads on roofs, the ice damming, condensation and ice backups in gutters, caused numerous problems.

As stated earlier, this winter season has been a treacherous one. Due to this fact, GRS would like to remind everyone to have an assessment completed on their roof for the next season BEFORE snow begins to fall.

Until next time,

The Team at GRS

CONTACT US:
General Roofing Systems Canada (GRS).
24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free.

info@grscanadainc.com

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.

Roof Snow Removal: Alaska Digs Out

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
warranted.
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 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.”

Contact Us:
General Roofing Systems Canada (GRS)

24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. info@grscanadainc.com.

 

British Columbia | Alberta | Saskatchewan | Manitoba | Ontario

Flat Roof Snow and Ice Removal | Flat Roof Drainage

General Roofing Systems Canada proves roof snow and ice removal services throughout Canada. 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.

The interesting thing about roof snow loads and ice problems is that homeowners are much quicker to respond than our commercial and industrial customers.

The truth is that commercial and industrial buildings are much more susceptible to roof failure, damage, or leaks than residential buildings.

Commercial Flat Roof Snow and Ice Removal
Commercial Flat Roof Snow and Ice Removal

The main reason for this is that commercial roofs are typically flat and in some cases metal systems.

To exemplify the complications, allow me to refer to a commercial client in Edmonton (bookstore on Whyte Avenue) who we serviced back in 2011. It took senior management hours to figure out how to safely get the ice dams and roof snow on various decks to the ground from that roof because there are so many variables involved. Consider as well that this was a five-storey building. The client, of course, is wondering why the crew is taking so long to begin with removal. The reality is there can be hundreds of variables to consider, check, and recheck prior to starting a commercial roof snow removal project such as this.

Considerations for a commercial or industrial roof can include (as was the case here), and may not be limited to:

Power lines, OHS (Occupational Health and Safety) concerns, pedestrian traffic, vehicular traffic, rooftop equipment of various kinds on different types of roof terraces, ground spotter safety, Bobcats and dump trucks operating, roof membrane considerations, window safety, unbalanced weight loads leading to collapse or significant structural damage, tie-off points, proper commercial insurance, and WCB (Workers’ Compensation Board).

The point here is there are many considerations when removing ice and snow from a flat roof system and far too many people just jump into shoveling off a roof without thinking through what may happen if the process is handled incorrectly.

An experienced flat roof company can also assess your roof while conducting ice and snow removal for any maintenance or repairs that may be required prior to the spring melt, at which times leaks will occur.

There is a Balance between Removing Ice and Damaging Your Roof

Ice build ups at Drains
Ice build ups at Drains

Far too many people, in our experience, desire ice to be removed and do so without considering the consequences.

The equipment and tools used for removal can damage the roof. Hammers, shovels, scrapers, chainsaws, spiker shoes, and de-icers are just some of the examples of what can cause damage to the roof, regardless of how careful you may be.

Ice on a Flat Roof or Low Slope Roof System

When assessing your roof and possible remedies, the considerations are:

  • Is the ice causing a structural problem with my roof?
  • Is it a potential hazard to pedestrian traffic below?
  • Will the ice cause issues with the flat roof membrane when it melts by way of leaking?

The rule of thumb when dealing with the ice on your roof is to do as little as possible and leave what is not going to hurt someone or cause structural failure. Removing dangerous ice overhangs, icicles, and making drainage paths may be all that needs to occur. Of course, if there is a structural concern, then more aggressive action may be necessary.

Most importantly, plan ahead. One of the main problems people have with emergency roof snow or ice removal is that they way too long. It is best to engage a roofing contractor early on to assess and get them active on your life. That way, if emergency services are required, you will naturally be closer to the front-end of service considerations for the contractor as they are already aware and on top of your situation.

The Most Common Solution

In most cases, the ice on a flat roof is dealt with by affecting proper drainage and not through complete removal. Snow can be completely removed, of course, but ice is mostly handled through effective drainage considerations.

Flat Roof Ice & Snow Assessment and Removal Procedures

Industrial Roof Snow Removal
Industrial Roof Snow Removal

As a general guide in Canada, most flat roof systems are constructed to safely hold a maximum of 15 to 20 cm of ice, 35 to 40 cm of hard pack snow (about 70 to 80 cm of fresh snow). If you are getting close to these numbers, or if you have a flat roof or metal low slope roof system that has large roof spans, you will need to lighten the roof load.

The trouble with assessing by depth of snow or volume is that many factors come into play.

  • Who built the roof system?
  • What was the specification?
  • Have there been renovations below? What are the spans?
  • How old is the roof system?

We have seen roof systems collapse that had snow loads under the general guideline above.

Ultimately, if you have a structural concern (look for signs of stress inside the building), contact a structural engineer as soon as possible

Flat Roof Snow Removal

As noted above, there can be hundreds of considerations when removing snow from a flat roof. The man goal, which many folks miss, is for everyone to go home safe and sound. We strongly encourage you not to take on the task yourself.

Flat Roof Drainage and Ice Issues

Ice expansion (later pressure from ice expansions) on a flat roof can cause significant damage to roof top units, parapet walls, flat roof flashing, skylights, elevator shafts, etc. To avoid damage and roof leaks, you can work toward drainage maintenance steps that may help the issues.

The goal is to separate the ice field on your roof from what ice expansion may cause issues with on your flat roof. 

Periodically, as winter progresses, you may have to go to work again at this and separate the ice from the aforementioned sections. Once again, we recommend a professional to take this on for you.

Steps to proper flat roof drainage with ice causing issues (central flat roof drainage systems)

Large Flat Roof Snow Removal Project
Large Flat Roof Snow Removal Project
  1. The first step is to remove the snow from the roof so that the warm roof underneath does not create ice. This is true for both commercial and residential high slope roofs.
  2. Use electrical cables to separate an ice dam or ice field from areas that may be damaged.
  3. Clear about 1 ft. to 3 ft. all around the drain area by using hot water or non-corrosive de-icers. If you really know what you are doing, you can use tools – but be careful not to damage the roof membrane.
  4. Lay the electrical cables (heat wire) starting at the drain and extending to each corner of the roof. Run loops around obstructions in the way such as skylights or rooftop units.
  5. If it is not too cold, the cables will melt their way to the surface of the flat roof giving you pathways for drainage.
  6. Chemical de-icers can be used in the same pattern, but be sure you are using non-corrosive de-icers.
  7. Hot water can also be used to cut drainage paths with some success.
  8. Steam trucks are not considered by most to be an effective method.
Contact Us:
General Roofing Systems Canada (GRS)

24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. info@grscanadainc.com.

British Columbia | Alberta | Saskatchewan | Manitoba | Ontario

Flat Roof Snow Removal Followup

General Roofing Systems Canada provides snow and ice removal services 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.

 

We are very pleased to report that all of our roofers made it home safe last night and the only buildings we heard about in terms of collapse were some quonsets, barns, and utility sheds (not to undermine their importance).

Crew at work, industrial removal
Crew at work, industrial removal

There was also a communications provider in the Edmonton area that called us with a partially collapsed metal roof system on an industrial style storage building.

Thus far, we have not heard about a home roof structure that has collapsed due to this storm we are experiencing in Alberta or Saskatchewan.

Also of note, when our sloped roofers are removing snow from residential roofs and conducting repairs, they inspect the attic space prior to check for roof ventilation problems, attic condensation that may be causing ice damming outside, vapour barrier problems, and compromised internal roof structures. We have not had any reports from the field of compromised high slope residential roofs, either.

The story is different, however, for low slope roofing systems in Alberta, Saskatchewan, and parts of British Columbia for all but residential areas. As far as homes are concerned, they seem to be holding up quite well.

This is what greeted our flat roofers on Wednesday morning when they arrived from Calgary to a site in Coaldale, Alberta:

Flat Roof Industrial Facility in Coaldale, AB
Flat Roof Industrial Facility

The flat roof service scope was to remove “some” snow and ice from a flat roof on an industrial building the size of a football fielding. One of our roofers commented that “it’s keeping our guys working and we are definitely getting into the best shape of the year.”

Our concern at this point is the volume of snow on some of these flat roofing systems. Adding the melt factor, and more snow on top of that, and the problems for these site owners will be compounded. I suppose we will just have to wait and see what transpires.

Contact Us:
General Roofing Systems Canada (GRS)

24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. info@grscanadainc.com.

British Columbia | Alberta | Saskatchewan | Manitoba | Ontario

Emergency Roof Snow & Ice Removal in Alberta

General Roofing Systems Canada provides snow and ice removal services 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.

Our Alberta roofing crews returning to our offices last night and early in the morning had many interesting reports with regard to snow and ice removal.

One report was not exactly heartening; fortunately, nobody was hurt.

One of our office staffers took a call mid-afternoon from an industrial facility just outside of Edmonton. The client was requesting emergency snow removal from an industrial corrugated metal roof system (low slope/flat).

While on the call, our operator could hear people in the background beginning to cause a stir. There were a few screams and a lot of noise. The distraught caller informed us that a portion of their roof had just collapsed.

Even more concerning was when our service manager arrived on-site. There were staff in the area of the building he reported to when they heard “snaps” and “cracks” coming from the roof. They left that room to inform their management what they were hearing while our office was on the phone with them [management] in the meantime. It was just as they left that area that the whole roof collapsed. ‘Just goes to show that a structural failure can occur without any warning and at any time.

It was a very emotional day. No one was hurt physically, but there were tears to be sure. Clearing snow, clearing ice… trying to help folks on the phone and in person when their homes are leaking very badly or their business roof is collapsing. Even more emotional in the life of the roofer is knowing that there are many more calls that we are not able to respond to when we get stretched thin during “tsunami” seasons.

Our crews continued to roll in through the night and the last of them arrived at about 4:30 am. We will start rolling out crews again sometime around 5:30 am and see how today goes. We are certainly hoping for everyone’s safety and the best for the business and homeowners that we will be dealing with. Serious leaks are expected to start coming in if we cannot remove the snow sooner than later for our current work-sites.

When questioning the crews arriving back at the office, we asked them what could be said or what could be taken and learned from the last 24 hours to assist folks affected by the snow and ice on roofs. This was their response:

  1. If you think your roof may have too much snow load, be sure to get it removed immediately or at least get a structural expert to inspect the roof for load capacity.
  2. If you hear anything at all that does not sound right, leave the building. Today was a real eyeopener for some.
  3. Take some preventative measures. Read up on roof ventilation and ice damming; fix the problems that cause ice buildup before it leads to structural failures. Remove the snow from your roof as soon as possible, and remove ice on the sides of buildings which are immediately hazardous to pedestrian and vehicular traffic.

Apparently, the Edmonton Journal had also caught wind of our latest crew experiences with ice and snow removal. (Update 7-24-2015: The link has since been removed from their website)

Below you will find some pictures from today’s crew reports. One shows over 40 in. of snow on a flat roof, obviously challenging load capacity. Another shows a roof collapse from the inside of the building (imagine how much snow was on the collapsed portion before that happened). Another photo shows a piece of ice on the exterior of a condominium building. Signs of leakage in the eave section of the low slope metal roof for this building will become evident when the melting begins.

40 inches on a flat roof
40 inches on a flat roof
Industrial site requiring removal
Industrial site requiring removal
Interior view of a collapsed roof
Interior view of a collapsed roof
Second collapsed view
Second collapsed view
Jan 17, 2011 Roof Ice, Edmonton AB 5
Ice damming on low sloped metal roof
Jan 17, 2011 Roof Ice, Edmonton AB 1
Metal roof reaching load capacity
Jan 17, 2011 Roof Ice, Edmonton AB 2 (1)
Ice damming along gutter system
Jan 17, 2011 Roof Ice, Edmonton AB 2
More ice damming
Jan 17, 2011 Roof Ice, Edmonton AB 3
Packed snow and ice dam growth
Jan 17, 2011 Roof Ice, Edmonton AB 4
Second view of the same

 

Contact Us:
General Roofing Systems Canada (GRS)

24 Hour Emergency Roof Repair: Call +1.877.497.3528 toll-free. info@grscanadainc.com.

British Columbia | Alberta | Saskatchewan | Manitoba | Ontario