Putting a new roof on a home is one of the biggest remodels a homeowner will make during the life of the home. In fact, if a person owned a home for twenty years it would not be unusual to see a roofing contractor twice during that time. Why? Because all roofing installers are not created equal and neither is the cost of replacing a roof.
Asphalt is the Norm
For the majority of Canadian homes the asphalt roof is roofing of choice. To replace them roofing companies have to strip the old asphalt shingles from the roof and put down new ones. In many areas the old asphalt shingles and tar paper are recycled into products such as paving material but in other places they are dumped in landfills or buried in non-designated areas. They are definitely not biodegradable.
The roofing manufacturers claim that the common three-tab shingles have life spans of 15, 20, 25 and 30 years - depending on the grade - and they put this on their packaging. However, the lifespan of a shingle depends upon many items outside the control of the roof shingle manufacturers: weather, sea air, trees, sun, etc. After all, the average asphalt shingle is composed of a paper and wood fibers soaked in a petroleum product and are susceptible to airborne solvents. The granulated-stone surface wears away and the exposed shingle begins to curl and get brittle, although the more expensive ones have a fiberglass-matte composition and last longer. And environmental studies have shown that an asphalt shingle in a landfill takes from 100-300 years to decompose.
Metal Roofs Gaining Ground
Metal roofs are not new to the Canadian landscape. In the 1960 s aluminum was the chosen material for wintry areas like British Columbia where the average snowfall is among the highest in the country. Despite there being a danger of sudden slides the metal shed the heavy snow quickly before there was any chance of the roof being compromised by the weight. However, they fell out of favour because of their appearance: shiny or dull metallic. As well, the first generation of aluminum was not a good platform for bonding with paint and was prone to wind damage because it was so light.
Today that has changed. Both steel and aluminum are coated with a UV-protection paint which will last many years longer than a normal shingle roof. If you are ever tired of the color you can purchase special metal paints which can be painted right over the old finish. As well, there are new locking systems that prevent gusts of wind from getting underneath and stripping off the metal pieces.
Metal roofs reflect heat which makes the attics cooler. In addition, to put on a metal roof you do not have to take the old one off. The process calls for the present roof to be strapped and the metal fastened to the wood strapping.
Aluminum has made a great leap forward as roofing material. Its weight, instead of being a detriment, is now a plus for buying the product because of new installing techniques and wind-resistant design.
- Standing Seam Aluminum Roofs: These are the traditional design but they can now be manufactured from spools of aluminum similar to a seamless gutter machine - so that there are no breaks to seal. The long strips can do from the roof peak to the rafter tail in one piece.
- Shakes: Besides the traditional standing seam lengths it now is manufactured in shakes which look like tile or wood shingles. These aluminum shakes interlock to form a complete roofing system that can withstand winds of up to 200 kilometre-per-hour.
Decades ago steel roofing came on the market as a competitor to aluminum. It was a good, lightweight product, and cheaper other metals, but its paint tended to peel and corrosion was a problem, especially in salt-laden air. The steel roofs of today are coated with either a PVC polymer or a metal alloy like zinc/aluminum. Like aluminum, the steel product also comes in tile form.
If money is no object then copper is the material for you. After all, thousands of cathedrals in Europe and most of the government buildings in Canada have copper roofs that have withstood the elements for over a century. Copper does not need to be painted because it oxidizes to the beautiful dull greenish-blue that we all know so well.
Is There Any Downside?
- Cost: A metal roof costs more than asphalt. Even though it will increase your house value look at double the price for metal.
- Noise: This is purely subjective because it depends on the pitch of your roof. These roofs make a racket so that a hailstorm might sound like thousands of cobblers hammering away. However, if you have plenty of attic insulation this may only bother your neighbours!
- Denting: If hit hard enough metal will dent, especially aluminum. However, metal shake roofs have more support and this shouldn t be a problem.
- Chips and Dings: Since it is a painted product there is a possibility of the paint chips, peeling and wearing in spots.
- Expansion: By its very nature metal expands and contracts. This can cause fasteners to come loose so the installation process is very important.