Residential flat roof and clear sky in Calgary
Residential flat roof and clear sky in Calgary

Flat Roofs in Canada

Flat roofs are an attractive option and is becoming more popular in new builds and can be a fantastic way to add usable outdoor space. Flat roofs are viable options for detached, semi-detached homes, townhouse or co-operative complexes. There is a prevailing assumption that flat roofs in Canada are only for commercial or industrial use, but good news for homeowners this is a highly approved new roofing option.

All roofs are designed to be either water shedding think of a steep sloped roof or waterproof; this is how flat roofs are protected. Flat roofs use membrane roofing systems and can be as simple as tar and gravel or as advanced as the “torched on” modified bitumen or single ply systems as explained below.

A flat roof is generally any roof with a pitch of 1- 10 degrees. Flat roofs do not always have to be completely horizontal and has a minimum slope of ¼ inch per foot. All roofs need a slope so that the snow and rain can drain somewhere, the drainage can be in the middle of the roof or at the edges in the form of gutters and eavestroughs.

Flat Roof vs Pitched Roof

What is the pitch and slope of your home's roof?

Pitch and slope are terms used to describe the angles of your home’s roof.
Pitch is the relationship between the roof’s rise – the vertical change in height for each horizontal unit of your roof and the span is the distance across your home’s roof. Slope is the relationship between the roof’s rise and run, or the horizontal change in distance across your roof.

Slope and pitch create a runoff for snow and rain, if there is not an appropriate slope on your roof there will not be sufficient drainage and can cause roof damages in the future. Snow and rain need to flow into a gutter system and away for the foundation of your home.

Benefits of a Flat Roof

Flat roofs are commonly used for commercial properties, and also can be an excellent material for homes with a low slope or completely flat top to the roof. Flat roofing provides many benefits to homeowners, in the form of usable space to their homes and is a low maintenance high protective roofing option. A flat roof does not shed rain or snow the same way, so it is important that it is installed correctly to avoid leaks or collapse. We can transform your property with a new flat roof.

When installed correctly by a professional roofing company, you can experience the following benefits of a flat roof:

  • Low maintenance and long lasting
  • Modern and clean design
  • Improves curb and aesthetic appeal
  • Watertight and provide protection
Your home will need a slope of 2:12 or less to get it installed. Unless your home is in need of a remodel, then contact a contractor to see if it is possible in the remodel of your home. This is a specialized system that requires an experienced and skilled installer.

Materials for Flat Roofs

Built-Up Roof Membrane (BUR) Material

Built-Up Roof Membrane (BUR)

The classic hot-tar-and-gravel flat roofing approach. The application includes three or more piles of waterproof membrane that are alternated with hot tar before a layer of smooth stone to ensure it is secure and tight. Fibreglass membranes can also be used during the construction.
Modified Bitumen Roofing

Modified Bitumen Roof

Another popular option for homeowners, modified bitumen roofs are similar to BUR roofs in which there are multiple piles. The only difference is the materials used: they are composed of polymer modified bitumen material, either atactic polypropylene (APP) or styrene butadiene styrene (SBS). It can be installed in various application methods, including cold and hot-applied, torch (heat) applied, self-adhered or mechanically fastened.

Rubber Membrane Roof (EPDM)

Rubber Membrane Roof (EPDM)

Part of the single-ply family (including Neoprene, PVC, and Polymer-modified bitumens), EPDM (short for ethylene propylene diene monomer) is a true rubber material and the most popular choice for residential properties. Its membrane material is durable, and its single-ply system makes the installation simple and effective, as it can be applied with fasteners, ballasted or glue.
Flat Metal Roofing

Flat Metal Roof

These can be made of copper, galvanized steel, pre-painted or coated steel, or tin. They are the most expensive type of roofing system (especially copper). Metal roofs are very difficult to repair. Once they have begun to rust and leak, a replacement is usually required and can be a big job. Metal roofs should never be covered with tar as moisture trapped below the tar causes accelerated rusting.

As flat roofs in Canada are becoming more popular is it important to remember to call a licensed roofing company and have your roof inspected throughout the seasons.

Flat roof issues in Canada - What to consider

Where does the water go? Snow, rainfall and hailstones

Drainage on roofs in Canada are vitale. The weather in Canada can be very extreme and there can be excessive water through snow and rainfall. Hailstorms should also be considered when getting a flat roof or considering doing a remodel of your home’s roof. Flat does not mean your roof is perfectly horizontal, as explained above. Your roof needs to be designed to handle the water and proper drainage. You never want water to just sit and accumulate on your roof, there needs to be a proper drainage system installed and maintained. If your flat roof is not maintained it could result in water coming into your home.

Most homeowners may have misconceptions when it comes to how a flat roof can handle the snow. Flat roofs have a low-pitch and so you must have eavestroughs collect the water as it runs down your roof, and safely directs it away from your home. You can also have an interior drain installed, which places a drain in the centre of your roof, connecting to pipes that drain water down through your roof.

Depending on the area of Canada you may live in, the local code is written to include minimum guidelines to handle any intended loads the roof is meant to hold. That accounts for its materials, membrane, insulation and decking. Snow, hailstones and rainfall is considered as well as air conditioners.

More to consider

If the added weight from snowfall is a concern, you could shovel some of the extra snow off your roof. Hiring a local company often when heavy snowfall hits is a great way to have your roof free of extra weight and keep the maintenance of your flat roof in good shape.

Flat roofs are the more expensive option, and if you take good care of your eavestrough, keeping them clear of debris, you should be able to use gutters without many issues. This is another job we suggest hiring a local gutter cleaning service for.

Flat roofs in Canada are new to remodels and to new builds, we are finding that more homeowners are switching to flat roofs. Flat roofs are not only for commercial buildings and can bring a sleek look to your home;s roof.

Here at Bear Valley Roofing and Exteriors, we specialize in installing flat roofs in Canada. Call us now and we will be happy to answer any of your questions about flat roofs.

FAQ’S:

Yes, you can. More homeowners in Canada are interested in having a flat roof done to their new build or renovation. Flat roofs were commonly used for being on commercial building but are now a viable option for homeowners.

When properly installed, flat roofs can last for up to 25 years. Ensuring that the homeowner has properly maintained the roof and have routine roof inspections completed. When properly installed, flat roofs can last for up to 25 years. Ensuring that the homeowner has properly maintained the roof and have routine roof inspections completed. When properly installed, flat roofs can last for up to 25 years. Ensuring that the homeowner has properly maintained the roof and have routine roof inspections completed.

First factor to consider when looking at a flat roof for your home is to think about what is the slope of your home’s roof to begin with or do you need to remodel the slope. First factor to consider when looking at a flat roof for your home is to think about what is the slope of your home’s roof to begin with or do you need to remodel the slope.

It is okay to buy a house with a flat roof in Canada. Flat roofs have made the transition from being for commercial buildings to detached, semi-detached homes, townhouse or co-operative complexes.

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