Asphalt Shingles: Most Canadian home builders use an  asphalt roofing system, due to the low cost ($30 – $50 per sq. ft), easy installation and improved quality. Standard asphalt shingles weigh about 250 pounds per square (100 ft. sq.), and last about 15 years.

Cedar Shakes:  For  homeowners  that  demand  wooden  roofs,  Cedar  shakes  can  be  purchased at a cost of approximately $150.00 per sq. ft.  Pine shakes are also available  and  have proven to be as durable as any other wood roofing product.

Aluminum and Steel Composite Roofs are being recognized  as a challenge to higher quality asphalt. Metal roofs combine lightweight and low cost with high performance and  very  easy application. Metal roofs are the fastest growing segment  of the roofing market in North America. These roofs weigh about 48 pounds per square and are sold as a complete system so costs  vary.

Slate Shingles are made from natural quarried slate, they have a life expectancy of 50 to 100 years. They are heavy and weigh about 5 times that of asphalt shingles. The biggest problem with slate shingles is not the shingles themselves but the nails that hold them. The flashing material as well will not last as long as the slate, typically made of metal, if the flashing rust a section of the roof may have to be removed and new flashing installed, this can be expensive and difficult.

Concrete and clay tiles are relatively rare though they have a life expectancy of 50-100 years. They are not effected by freeze frost cycles, they withstand wind and rain, absorb little moisture and defy termites and rodents.

Recycled roofing products such a s Woodruf traditional shingles from Masonite are made from wood fibers  bonded together to form a dense shingle  more  durable than natural wood. They are easy to install and they look like real cedar at a fraction of the cost.

Crowe industries limited of Hamilton produces Authentic Roof slates, made from 100% recyclable ploymer and rubber. The slates are fastened with standard nails to any roof deck and have a 50  year warranty.  Though the cost  is high ($5.00 per sq. ft.) the product has a 100 year life expectancy.

There are many systems available on the market which contain recycled metal. Reclaim Inc. of Florida is presently  recycling  old  shingles  into  paving products.


A proper reshingling job involves removal of all old shingles. Some people apply a second or third layer of shingles which can add unwanted weight that the roof supports were not designed to carry. Wet asphalt shingles can increase in weight by 50%. In addition new shingle warranties will not apply.

The roof should be stripped to the sheathing to ensure that it is in good shape. Spruce plywood is a far better sheathing than aspenite as aspenite tends to swell along the edges where water is allowed to collect. Roofing felts add to the cost of  the roofing job, though there is a divide in the train of thought regarding the usefulness of felt.

One opinion is that shingles need to breath and roofing felt hinders ventilation, causing shingles to curl and shorten their life expectancy.


Natural enemies of any roofing system include the sun, rain and wind. The warmth and ultra violet rays of the sun cause roofing materials to dry out, overheat and deteriorate. The sides of the roof with southern exposure often wear out faster than the other sides, especially if they are dark, since they absorb more of the suns rays. Where rain water finds its way through the interior of the roof structure, it sets up a moisture condition that is conductive to mildew and rot. It can destroy drywall, render insulation useless and jeopardize a homes electrical system. A strong wind can actually lift shingles off a building, as well as drive rain water under the edges of roof shingles. Trees should be trimmed away from the roof to avoid damage from wind or pest such as squirrels or raccoons. There is a treatment that can be sprayed onto the roof which protects it from weather conditions and revitalizes the color at a cost of .45 per square foot. New shingles contain oils which over time are lost due to ultra violet radiation. They curl, crack, loosen, leak, and cause costly damage. The Ultraviolet blockers protect against sunlight damage.


The roofing industry’s standard warranty is made up of two elements. The  manufacturers prorated replacement warranty (12,15,20,25 and 30 years), and the installation warranty. Most roofing contractors offer a maximum of 5 years.

Warranties vary from company to company, some are transferable and some are not. It is important that the home owner understands the coverage he has, and the certificate of transfer should  be included if the house is sold before the warranty runs out.