When is it time to remove snow from your roof?

Dimitris Ilias

The recent accident in Sainte-Thérèse covered in another news item in this issue of the North Shore News brings in to the front the issue of snow removal from roofs. Even a small structure such as a tempo once it accumulates enough of the white stuff can become a death trap.

So when is it time to take action?

Under normal winter conditions and as long as there have been no modifications to the building structure, you probably don’t have to worry about clearing the snow from the roof of your home.

Both flat and sloped roofs are, in principle, built to withstand the snow loads that can be expected in specific regions of the country. One can see as an example houses built several decades ago and their roofs have stood up to all those harsh winters of years past.

Residents have to be more careful with higher accumulations especially if there is a later thaw, or a period of freezing rain. When this happens, the snow load will be considerably heavier, and ice may prevent draining from your roof.

At what point should a homeowner be worried about structural weakening or water infiltration, and clear snow from their roof as a preventive measure?

An overloaded roof will give signs. In critical periods, one must be alert to such warning signs as unusual cracking sounds, warping of a ceiling, cracks appearing in wall and ceiling plaster, or doors starting to jam. If this happens preventive action should be taken.

A few tips for clearing the roof

Clearing snow from a roof is delicate work. One must ensure use of wooden or plastic tools, without sharp points or cutting edges. Not to mention the fact that working on the roof involves the risk of falls or even electrocution – so it’s highly recommended that the job is entrusted to a roofing specialist who has the required skills, experience and equipment. If the roof is still under warranty, the contractor who provided the warranty must first be called. Also, there may be no need to clear all the snow from the roof. This depends on the type of roof: with a flat roof, the drain must be clear and then the drainage paths that converge toward it opened; on a sloped roof, the drainage paths to ensure that water can run normally down to roof edges.

In either case, the bottom layer of snow must always be left in place to prevent damage to the waterproofing membrane. Also, the snow should not obstruct the plumbing vents and the roof vents, which on a sloped roof help to ventilate the attic.

What about insurance in case of damage

If the weight of the snow or water infiltration causes damage to a home or belongings, know the home insurance might be of use! Choosing a home insurance policy suited to Quebec weather conditions is a good way to protect yourself in case of unpleasant surprises! Don’t hesitate to talk to your insurance agent.

Tips for professionals

When professionals are hired to clear the roof of snow, they must follow these expert safety practices:

DO NOT use metal shovels, which can cause roof damage. Plastic shovels will protect the surface of your roof

DO NOT load up snow on the weaker sections of the roof, not even temporarily while removing it

DO NOT ever drop snow over fire escapes or in front of a building’s entry points

DO remove snow starting from the ridge and working down to the eaves

DO leave at least a couple inches of snow (instead of scraping the roof clean) to minimize the risk of roof damage

DO focus on removing rooftop snow drifts first

DO use roof fall harnesses and all other OSHA-required safety equipment

DO review a blueprint of the roof or ask the homeowner (you) about the location of any vents, skylights, or other projections

DO have a worker stationed below at all times to keep people from walking in areas where snow will be thrown off the roof or mark such areas well to give adequate warning

Sources: heattrak.com and caaquebec.com