Roofing Materials
There are a number of roofing materials available on the market today. Choosing the perfect one for a home will depend on the structure and steepness of the roof, the environment where the home is located, its aesthetic appeal, and budget. The following are a few examples of the most popular types of roofing materials in North America:
Asphalt shingles
Most homes in North America with steeply sloped roofs are covered in asphalt shingles.
Asphalt shingles are durable and extremely affordable. They are produced in several colours and styles, and with such a wide selection, homeowners will no doubt find asphalt shingles suitable for their home. There are “architectural” or “laminated” shingles that appear three dimensional, and “self-sealing” shingles that provide extra adhesive support against harsh winds so that no blow-off occurs. In some regions where algae grows profusely to cause dark stains and potential health problems, manufacturers offer shingles that have been treated with algecide (another solution is to simply install zinc strips on the roof, so that zinc particles are carried by runoff water to the algae to eliminate it).
All asphalt shingles are produced in generally the same way. A coating of coloured mineral granules made of crushed rock coated in ceramic is applied to a mat made from either wood, cellulose or fiberglass combined with waterproof asphalt. Over time, the shingles will shed some of these granules, collecting in gutters and at the bottom of downspouts. When doing a routine cleaning of the gutters and downspouts, checking the amount of these shed granules can give you valuable insight into their condition.
A drawback to asphalt shingles is that their lifespan is normally about twenty years. Damage can result from harsh environmental factors or poor installation, so they require routine check ups to monitor their condition. If any wear or tear appears, repair should be done immediately to the damaged shingle(s) to prevent serious damage. Serious damage includes water leakage affecting the supporting structure, which could be irreparable.
Chipped shingles should be completely replaced. Old shingles that curl down or upward should also be replaced, however, they can be sealed down with roofing sealant at the corners if the curling has just started. For cracked shingles, roofing sealant can be applied underneath and on top of the crack, then covered with the same coloured mineral granules that coat all of the other asphalt shingles. If blisters appear in the shingles, this may be an indication that moisture has become trapped under or in the shingle. If it is under, the shingles were not installed properly. If it is in the shingle, simply replace it.
It is highly recommended that asphalt shingles are not painted, as they may deteriorate faster.
Metal
Lightweight and resistant to fire, metal roofs can be made from aluminum, galvanized steel, copper, zinc, stainless steel, and titanium (the most expensive). Metal is more expensive than asphalt shingles, but are longer lasting and require less maintenance. If installed properly, the only threat to a metal roof is rust. However, rust can be controlled with the application of protective paint, rather than replacing the whole roof.
Aside from metal roofing that resembles shingles or tiles, there are two main types of metal roofing: structural and architectural. The type of metal roof suitable for your home will depend on its pitch.
For steeply sloped roofs, architectural metal roofing systems that are standing-seam steel are ideal. Also called non-structural, their smooth, slippery surface make it ideal for runoff water and snow to slide easily off of structures. Gutters and downspouts should be sized accordingly as they may need to accommodate larger amounts of runoff traveling at a faster speed. In the design of this type of roof, custom cut metal sheets are used, with joinery created by connecting adjacent metal sections from upturned portions of the metal.
In buildings with low pitched roofs, a structural metal roofing system is required. While architectural systems require an underlayment normally made out of wood, the structural system does not and can span joists without the support of an underlying solid deck.
Metal roofs are ideal for warmer climates, such as the southern United States. As metal reflects heat, cooling costs will be reduced dramatically with proper insulation.
Metal gutters and downspouts attached to a metal roof can be more aesthetically pleasing, as there is continuity in their appearance. However, it is necessary that sealant is applied at the gutters to keep it waterproof.
Wooden Shakes and Shingles
Roofs made from wooden shakes and shingles normally require routine maintenance, as damage can easily result from mold, rot, and burrowing insects. On the other hand, they provide good insulation and ventilative properties because the shingles/shakes are made from a porous and organic substance.
The difference between wooden shakes and wooden shingles is their shape. While shakes are textured with splits and thicker at the butt end, shingles are the same thickness throughout.
Wooden roofing materials should be treated with fire retardants to reduce their fire hazard. In fact, in many cities where wooden roofs are allowed, this treatment is required by law.
Wooden roofs tend to deteriorate quickly from long term exposure to water. Therefore, it is important that runoff water be directed correctly to the gutters and downspouts so that no water pools on the roof.
Tile Roofs
A tile roof is a beautiful addition to your home that is durable and long lasting. They can be manufactured from concrete, slate or clay and come in a variety of shapes, weights, and sizes. Some may be specially treated to keep them from changing colour as they age.
A major drawback to tile roofs is that because it is made out of a naturally dense material, the total weight of the roof can be quite heavy. As a result, some structures may not be able to support this weight. Installation requires skilled labour, and though routine checkups are done less frequently than other types of roofs, it is recommended that professionals are hired for the task as they are expensive to maintain or replace. This advice may also extend to other aspects of roof maintenance, such as gutter cleaning and painting. Hiring a professional who knows how to work on or around a tile roof can reduce or prevent any damage that may result from those less experienced.
