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Roofing
November 20, 2023

Protecting your roof from snow and ice damage

Winter weather can be great; whether you’re bundled up in coats, scarves, and hats, enjoying the beauty of winter snowfall, or snug in front of the fire with a mug of cocoa in your hand. Unfortunately, the cold weather during the winter months can also be extremely damaging to your property – particularly to your roof and guttering.

When you experience heavy snowfall and biting winds, there’s always the danger of roof damage to follow. Ice dams, snowmelt, and other related problems can all cause serious issues if you’re not careful. In this article, we will look at some of the ways snow and ice can affect your roof, how to clear them from your roof, and how to reduce the risk of it happening again.

How snow and ice can damage your roof

There are several ways in which a heavy snowfall can cause damage to your roof. These are some of the most common ones:

Overloading your roof

Snow is heavier than it appears. It may look light and fluffy when it comes down, but when it settles on your roof, 10 inches of fresh snow weighs in at around 5lbs per square foot. Packed snow can be double the weight or more. Since most modern roofs in good condition can take 40 lbs of weight per square foot or more, but as your roof ages this load bearing capacity can diminish. A few feet of snowfall over a couple of nights can easily put your roof in the danger zone.  

Damaging gutters

It’s not just your roof that feels the weight of the snow – your soffits, fascias, and guttering can also suffer. In fact, your roofline faces several problems. The weight of the snow can seriously damage your guttering, as your gutters are generally less durable than your roof.  With metal roofing in particular, it is important to make sure that you have the right snow retention system in place. Certain gutter materials can crack under extreme cold, particularly if an ice dam should form. Finally, once the snow begins to melt, the sudden rush of water could prove too much for your gutters.

Forming ice dams

If the roof over your attic space is warm enough, it can melt the snow touching it. This snowmelt trickles down until it reaches the edge of your roof which, since it is extended beyond the attic space, is still cold. Here the water freezes, creating a barrier of ice. As the ice dam grows, the snowmelt that follows has nowhere to go, so it seeps under your roof shingles, slowly leaching through the insulation and into the walls and ceilings, causing significant water damage. When the dam starts to melt, it can break and fall, pulling away gutters and shingles with it.

Avoid damaging foundations

This is less of a concern during the cold weather, but something to worry about as it gets warmer. As the snow melts, you can expect a cascade of water to hit the ground around your property. If there are small cracks and fissures in your foundations, the water will seep through these into your walls and basement. Left unchecked, the problem will only get worse the next time it snows, as the ingress of water will weaken the concrete foundations further.  To avoid this problem, it is important to make sure your gutters are clear and in good working order.

How are different roofs affected by snow and ice?

Not all roofs are built the same and certain designs and materials can increase or decrease the danger of snow and ice damage. These are some of the things you should consider:

Age

Old roofs, by definition, have been through a lot. They’ve withstood dozens of bad winters over the years and experienced their fair share of ice and snow. Even a well-kept and well-maintained roof can suffer from advancing years, so don’t just disregard those creaking timbers that you hear at night. Have an expert roofer take a look and make sure your roof is still fit for purpose.

Flat roofs vs. Pitched roofs

Generally speaking, the higher the pitch, the less chance you have of snow building up, as the angle will cause snowfall to roll off and into your gutters before it has a chance to stick unless it’s particularly heavy snow. High-pitched roofs are also less likely to develop ice dams for the same reason – the melted snow will run off the eaves before it has a chance to freeze over. Flat roofs are the worst for extreme winter weather. With nowhere else to go, the weight of the snow will build and build until the roof beams buckle beneath it.

Shingled roofs vs Metal roofs

Metal roofs fare extremely well in cold weather. Snow is likely to slide right off, which should prevent ice dams from forming.  As previously mentioned, the key here is to make sure you have adequate attic insulation. When there’s a lot of heat loss through a roof, oftentimes this can cause water from melting snow on the roof to refreeze as solid ice as it gets farther from the source of warmth. By maintaining the temperature a little cooler, ice and snow melting happens more slowly allowing time for it to drip off naturally or get cleared away by other methods. Keeping your home's energy expenditure down is something that most people will want to do anyhow because it saves us money which is always a wonderful thing! Shingles are more prone to snow damage since they can crack in extreme cold, or be torn away by melting ice dams.

How to prevent snow and ice damage

The best way to prevent damage to your roof from snow and ice is to adequately prepare for the cold weather. Make sure your roof, gutters, and foundations are in good condition, invest in snow clearing equipment, and ensure any repairs have been made ahead of any coming snowstorms.

Check your roof

Inspect your roof for cracked, loose, and missing shingles long before the cold weather arrives.  Gaps in the roof won’t just lead to leaks, but will also weaken the structural integrity of the roof as a whole, making it more likely to collapse. Check the roofing, as well as the decking and sheathing if you can. If you experienced damage the previous winter, you should always hire a professional roofing contractor to check the rafters and roof timbers to ensure they are fit for purpose.  The sooner you can check, the better as most reputable roofers have full schedules weeks or even months before winter weather arrives.

Check your roofline

As well as looking for roof damage, you should also inspect your roofline – which includes the soffits, fascias, and guttering – for signs of damage or leaks. This is part of the roof that is easily overlooked, but which can prove particularly vulnerable to ice dams. Again, if you’re not sure what you’re looking for, a roofing contractor or guttering specialist will be able to help you.

Invest in a roof rake

A roof rake is your best defense against sudden snowfalls. These extendable tools are designed to pull loose snow off your roof before it has a chance to form heavier packed snow and overload your roof. Roof rakes can also be used to break off icicles and ice dams. This can take quite a bit of effort and a certain amount of upper body strength so make sure you’re up to the task. This method works best if it’s done while the snow is still soft, before it has had a chance to start melting.  You should also be mindful of the snow and ice you’re pulling free from the roof – that stuff is heavier than it looks, particularly when falling from a height. Lastly, if you have a shingle roof take care not to push to hard – after all you don’t want to damage the roof you are trying to protect.

Keep your attic space cool

Speaking of ice dams, the best way to prevent them from forming is to make sure your attic space is not too warm. Check the insulation between your living area and the attic to ensure it is sufficient to prevent heat from escaping into the attic. Add vents between the insulation and the roof sheathing as this will allow any warm air that does get through to be carried away via convection.

Check your drainage system and foundations

This will help you minimize any potential damage from melting snow and ice cascading from your roof. Clear your gutters of any obstructions and see that they are properly angled to channel water away from your property and into the drains. Ensure any cracks in your foundations are sealed and, where possible, alter the grade of the land around your home so that it slopes away from the house. These are major undertakings and may require the assistance of a professional groundworks company.

When in doubt, call the experts

With these tips, there is no reason you should have a beautiful wintertime experience, free from worries about snow and ice on your roof. Remember, many of these jobs require skill and experience to get right. You shouldn’t climb out onto unless you know what you are doing.  This is especially important when dealing with a slick, icy roof. If you’re not sure if you can handle it, get in touch with a local roofing company that can.

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