Flat Roof vs Pitched Roof: The Pros and Cons

Flat roof cons

Because of the variety of materials used for flat roofs, it’s a little difficult to generalize the pros and cons.

Depending on the material, some flat roofs develop cracks more easily than pitched roofs. Cracks mean leaks – not good for any roof.

Some flat roof materials/membranes are sensitive to temperature fluctuations, which can be extensive in Calgary and Edmonton especially, so cracking can be a problem unless spotted early and fixed.

The other main drawback with flat roofs is potential difficulties with drainage. Though they do offer a slight slope, the runoff of water is much easier on a sloped roof where gravity helps. Heavy rain can cause water to pool, potentially leading to leaks.

In areas of high snowfall, snow can build up more easily on flat roofs too, creating other challenges with the weight of the snow and drainage after it melts. Flat roofs require a waterproof seal, which must be maintained regularly to prevent leaks and costly repairs.

You might read in some places that flat roofs have a shorter lifespan than pitched roofs. This is not necessarily true. Some well-maintained metal flat roofs can last 50 or 60 years, and modified bitumen, built-up or membrane-based roofs can last 30-45 years with proper maintenance and care.

What is a pitched roof?

Pitched roofs come in a variety of styles but they all have one common feature: they have a visible “peak” and a slope, creating a triangular appearance.

Gable, cross gable and hipped designs are all commonly used in pitched roofs, the main difference being the angle of the slope.

Most commonly, you see pitched roofs on residential homes in Calgary, Edmonton and Vancouver. They form a tall attic at the top of the home that can be put to good use as a storage space or a bedroom. However, pitched roofs can also feature on some commercial buildings.

Pitched roof pros

A major advantage of sloped roofs is that they have a natural drainage system, allowing gravity to look after the flow of water down from the roof to the gutter system. With heavy rains, property owners with sloped roofs have few worries about water pooling on the roof.

Also, compared with flat roofs, there is less chance of snow build-up during times of heavy snowfall, as it usually slides off relatively easily when it starts to melt.

For commercial buildings, aesthetics is often less of a factor for building owners than it is for residential property owners. Practical considerations normally come first, so the more “homely” appearance of sloped roofs is usually not a deciding factor for commercial building projects.

Depending on the material you choose for your pitched roof, you can expect a lifespan of 20 to 50 years –similar to flat roofs.

Ass discussed below, all roofs require regular maintenance, but some consider the maintenance requirements of pitched roofs to be lower than with flat roofs due to the reduced chance of water and debris building up.

Pitched roof cons

Because of their sloped and peaked design, a larger support structure is required for pitched roofs.

Additional materials and specialist expertise may be required, so a significant disadvantage of pitched roofs is an increased installation time and potentially higher upfront costs. Generally speaking, therefore, pitched roofs are more expensive than flat roofs.

Also, repairs and maintenance of the roof are more challenging than flat roofs because of the dangers of working on a slope. Whereas a building owner can usually inspect a flat roof easily by walking around on it, this is much more challenging with a pitched roof.

Finally, in times of high wind, a sloped roof may have a higher potential exposure to damage than a flat roof, all other things being equal.

Choosing the right roof for your commercial building

Commercial buildings have different priorities from residential ones. While cost and durability are essential to both, aesthetics generally become less critical for commercial building projects, and practicalities such as safety and maintenance requirements are the primary considerations.

Bear in mind that the climate in Calgary and Edmonton is different from that of Vancouver. The colder temperatures and heavier snowfall are all issues to consider before installing a roof in Alberta.

Generally speaking, for commercial buildings all over Canada, flat roofs are the go-to design. They are cost-effective, durable, safe and practical for most retail buildings, office towers, condominiums and apartment buildings, and other commercial and industrial buildings.

Maintain your roof for extra longevity

The secret to extending the life of your roof is regular maintenance.

This applies to almost any roof because problems can be flagged early and fixed well before a roof replacement becomes necessary.

A flat roof should be inspected professionally at least once a year, if not more regularly. They are susceptible to water pooling after heavy rain or snow, and standing water on a roof is never a healthy sign.

Because of their accessibility, most flat roofs are relatively easy to inspect by walking around with a detailed checklist. Try to inspect your roof regularly in between the annual professional maintenance checks.

You can also extend the life of your roof by getting the right professional advice before you decide on design and materials and by ensuring that you install it with a reputable company.