Modern Roofing Trends

We all must have a roof over our head in Canada; the weather demands it! This discussion of roof covering materials may help guide you in deciding which type of roof covering is right for your home when it comes time to build a new home or replace an existing roof covering.

The Most Common Shingle

By far, the most popular roof covering in Canada is the asphalt shingle.  It is used extensively on new builds and replacements. The older "organic" asphalt shingles consisted of a layer of wool felt, infused with liquid asphalt (tar) and covered with a layer of fine stone grit (in various colours). The stone grit is not just decorative; it also protects the asphalt from ultraviolet (UV) rays from the sun. The UV rays will, over time, act to break down the asphalt. This breakdown accelerates as the stone grit is lost to weathering.With organic shingles, this results in "curling and/or clawing" behaviour, lifting the edges of the shingles and making them more vulnerable to wind damage.

The more modern "non-organic" asphalt shingles mainly differ in one respect.Instead of using an organic layer of wool felt, non-organic shingles use an asphalt infused fiberglass mat; still covered with a layer of fine stone grit. The non-organic shingles will not readily absorb moisture and they are unlikely to curl and/or claw like organic shingles. Since they lay more flatly against the roof, they are less likely to suffer wind damage. And they are more tear resistant.While the cheaper organic shingles may still be available, the vast majority of shingles sold today are the non-organic type.The non-organic shingles, depending on local exposure and climate, are likely to remain serviceable for roughly 10 more years than organic shingles.

Shingle Design & The Wind

Another factor determining susceptibility to wind damage is the shingle design. Traditional three-tab shingles, with more exposed edges, are more vulnerable to wind damage as they age.Modern "architectural" shingles have a laminated structure and have one continuous bottom edge. They are more rigid and have less wind exposed edges.

The other factor that makes the roof shingles more or less secure is how well they seal to each other. Modern asphalt shingles are manufactured with a hard strip of tar on the top side and a thin strip of smooth plastic on the underside. The shingles are installed in layered rows starting at the bottom edge of the roof eave. They are positioned so the plastic strip on the underside lays against the tar strip of the shingles in the row below.  When exposed to the sun, or in warmer weather, the tar strip softens and adheres to the plastic strip above. That seal makes them less vulnerable to wind damage.

It is important, therefore, to install shingles when the opportunity for them to seal properly is best; so spring, summer or fall depending on where you live. If you do suffer wind damage in a winter storm, you should avoid a total replacement and just complete enough repair to keep the roof weather tight until warmer weather occurs. Winter repairs or replacement should be completed using roofing cement to allow the replacement shingle to adhere in the colder weather.

When To Replace Your Asphalt Shingle Roof Covering

As the roof covering ages, it become increasingly vulnerable to wind damage. Missing or damaged shingles can lead to roof leaks and consequential damage to the interior of your home. In addition to replacing the roof covering, interior repairs can be very expensive. So it is always best to be proactive. Monitor your roof condition as it ages. As the stone grit wears off the surface, the asphalt will begin to suffer progressive damage from the sun's UV rays. The exposed bottom corners may start to curl, or the shingles may start to shrink and become more brittle - more likely to break in a strong wind.Professional home inspectors are trained to assess the condition of your roof covering and can offer an unbiased opinion on remaining service life.

Getting A Quote

If your shingles do need replacement, it is important to hire a reputable roofing contractor for the removal and replacement of the old roof covering. You should obtain three written quotes and investigate the bidders online and through the referrals they supply. The quote should be thorough and include the costs of pre-installation materials such as roofing membrane, ice and water shield, ridge vents, and flashings. Bear in mind that their work is seasonal, and contractors will be difficult to book on short notice. So obtain quotes as early as possible.While a roofer may not be doing installations during the winter, they are available to provide estimates.

Other Roof Coverings

While asphalt shingles are the most common type of roof covering in Canada, there are alternatives that you can consider when building a new home or replacing your present roof covering.These are more or less practical depending on where you live and what your budget is.Generally speaking, the alternatives are more expensive.So pricing and motivation can be factors when making a choice of roof coverings.

Metal

There are two primary types of metal roofing, both of which are most often manufactured using galvanized steel – for its strength and durability.These roofs are often pre-finished with an anodized paint treatment and can come in a wide variety of colours.

There are metal shingles that are installed similarly to asphalt shingles. These shingles often are interlocking and are very wind resistant. The other type is sheet-metal roofing. These large sheets may or may not be corrugated and are frequently installed over the older roof covering.

These metal roofs are very likely to outlast their owners, so in a newly built home, amortizing the extra costs associated with a metal roof will soften the blow to your cash flow when included in the mortgage.If you are installing metal as a replacement roof, you should be aware that it may be difficult to recover the extra cost in the short term as prospective buyers of your home are unlikely to see that as a deciding factor for which they are prepared to pay extra.

If you are planning to install solar panels on your roof, a metal roof could be a positive consideration as it will likely outlast an asphalt shingle roof.This means that you probably will not need to demount the solar panels to allow roof replacement.

And we must not forget to mention copper as a roofing material.It is very expensive but has a high visual appeal for the pale green patina that occurs as a result of surface oxidization.It is not, however, a practical material for a typical Canadian home.

Modified Bitumen

For low slope or flat roofs, a roll type roofing material known as "modified bitumen" can be a good choice. This material is similar to an asphalt shingle roof, but comes in rolls. The sheet material is infused with bitumen (tar) and is finished with a fine stone grit to protect it from the sun's UV rays.The seams are overlapped and heat-sealed with a torch to make it wind and waterproof.Make sure your contractor has specific experience with this type of installation.

Cedar Shingles

While not in wide use any longer, given the expense, cedar shingles were a popular roof covering in some parts of the country. It was less expensive in years gone by and had a broad appeal for its esthetic and durability. However, cedar shingles are not maintenance free and need to be cleaned regularly to maintain their appearance, and to remove organic growths such as moss.It is also of note that they are not as fire resistant as most other roofing materials. Some jurisdictions have banned them from use for that reason.Also be mindful that very few modern roofing contractors have experience installing cedar roof shingles.

Clay Tile

These are mentioned only because you may be familiar with them from travel in warmer climates. While beautiful in appearance, they do not do well with Canadian winters where we have multiple freeze/thaw cycles.

Just The Basics

The foregoing is a basic discussion about typical residential roofs. There is much more to say when you begin talking about installation methods and standards. Hopefully you are able to choose a roofing contractor with credible experience to guide you through that discussion.