Asphalt shingles, the most common roofing material, are easy to install and less expensive than other roofing options, such as metal cladding, slate, or steel sheeting. To make an informed choice, it is always recommended to understand the main features of the various models available.
The purpose of this buying guide is to help you select the most appropriate shingles for your roof. You should consider the following criteria: slope, appearance (if your roof is visible from the street), wind-resistance, water-resistance, durability, and warrantee.
Are durability and warrantees important purchasing criteria?
Should shingles be expected to cover imperfections in the sheathing?
Should the shingles I choose be wind-resistant?
If the roof can be seen from the street, how do rate appearance as a deciding factor?
Asphalt shingles are the leading choice for residential roofing, accounting for more than 75% of all roofing materials installed. Asphalt shingles have evolved considerably over the past ten years; as well as protecting the roof, new shingles boast new features that make them “greener”: improved energy performance, solar-reflective shingles that reduce the roof’s temperature in summer, and the use of recycled materials.
There are two main categories of asphalt shingles: organic and fibreglass.
Organic-based shingles are the oldest type of asphalt roofing tile. The organic part of asphalt shingles is a cellular fibre substrate, often recycled paper, impregnated with asphalt and compressed under high pressure. More flexible than fibreglass shingles, they are easier to install in cold weather, more tear-resistant and able to hide imperfections on the roof’s deck. Organic shingles are heavier and therefore more resistant to strong winds. And more important in our northern climate, they are better at withstanding changes in temperature.
Currently more popular: asphalt shingles manufactured with a mat composed entirely of glass fibres, referred to as composition shingles. The fibreglass mat is surfaced with an asphalt coating, followed by mineral granules. Laminated or architectural shingles are somewhat thicker due to an extra layer of tabs. Fibreglass shingles are lighter than their organic counterparts, because less asphalt is used during manufacturing, and they are less expensive. They are also more heat-resistant and the “feet”, or notched ends, are less likely to lift, a problem often encountered on older roofs. An underlayment of asphalt-saturated felt should be installed over the roof structure prior to laying fibreglass shingles.
1- Granular surface layer
Granules constitute the superficial layer of asphalt shingles, provide colour and UV protection. This granite-like coating comes from basaltic deposits, including basalt and rhyolite, which are not only hard and durable but opaque to keep UV rays from deteriorating the asphalt. Certain granules are engineered to reflect heat and keep roof temperatures cool. They also may contain additives to prevent mould.
2- Asphalt coating
Asphalt is the waterproofing agent applied during manufacture, ensuring the roof’s protection. The thickness of the asphalt layer determines the weight of the shingle. Architectural shingles have two layers of asphalt, with the fibreglass mat constituting the centre.
3- Base, or mat
The material used for the base, or mat, differentiates the types of shingle and provides the shingle structure. The base for organic shingles is made of organic felt saturated with asphalt, whereas the fibreglass shingles are reinforced with a glass mat. This membrane acts as a frame, holding the other layers together; it must be very resistant and stable in all temperatures.
4- Adhesive tabs
Shingles come with heat-activated adhesive tabs. Never drive a nail through these adhesive tabs, which could prevent shingles from fusing or locking to the roof deck.
5- Nailing strip
Shingles must be nailed and not stapled, which makes them more vulnerable to cracks. Nail heads should be visible on the surface without being driven too deep.
The combination of adhesive and nails provide shingles with wind-resistance. The majority of shingles can resist winds more than 100 km/ h, and high-performance shingles provide protection and resistance to winds up to 220 km /h.
Solar Reflectance Index (SRI)
SRI is a measure of the roof’s ability to reject solar heat. New granule technologies have been developed making shingles more solar-reflective, and ensuring cooler roofs and attics during summer. The granular layer reflects the sun’s rays without affecting roof-colour.
There are many shingle models on the market, available in various colours. Each model has different features (thickness, durability, function). With the increased occurrence of major weather disruptions, such as heavy rain and strong winds, manufacturers have improved their products to make them more resistant to extreme weather conditions. Weather-Tite technology provides protection against high winds (up to 220 km/h) due to the application of sealant bands on shingles. Manufacturers also offer products more resistant to heavy rain. Warranties have been adjusted accordingly. Here are the various models:
Economical and popular;
Rampart; Dakota; Mirage; Yukon; Superglass Ultra
Up to16 colours available depending on the brand and manufacturer.
Three quality levels associated with three warrantees (20, 25 or 30 years)
Have become increasingly popular;
Up to 16 colours available depending on the brand and manufacturer.
Manufacturers offer a Lifetime Limited Warranty
Up to 12 colours available depending on the brand and manufacturer.
Solid 15-year protection;
Shingles designed for the ridges and crest of the roof. Available in one, two or three thicknesses.
Up to 7 colours available depending on the brand and manufacturer.
Manufacturers offer the same warranty for these shingles as for laminated shingles
Shingle half the size as a regular shingle (approx. 8"), designed to begin installation
The slope or pitch of a roof dictates the type of shingles you should install. For a low-slope roof such as 4:12 (a ratio of 4 inches of rise to 12 inches of roof) to 2:12 (a ratio of 2 inches of rise to 12 inches of roof), three-tap shingles are preferable. Low-slope roofs are more susceptible to ice and water problems such as ice dams, so that more attention must be paid to water-resistance.
For an average-slope roof (more than 6:12) or high-slope roof (8:12 to 12:12), architectural shingles are recommended.
Asphalt shingles should never be installed on roofs with a slope less than 2:12 (8.5°).
For a roof with two slopes, add the surface area of the two slopes plus 10% to cover the crest of the roof. This 10% also enables you to cover any losses. The percentage is higher in the case of a roof with several slopes with ridges, verges and valleys. The manufacturer or retailer is a good resource-person to estimate the exact quantity you’ll require.
For laminated shingles, the calculations are different. You need to add the surface of the two slopes plus only 5 to 7%. This excess consists of three-tab shingles, needed to cover the crest of the roof. Remember that with laminated shingles you need three-tab shingles to cover the crest and ridges. To help you with your calculations: each package of three-tab shingles covers 30 linear feet.
Installing shingles on a simple roof with two slopes is fairly straightforward and can be done by home-owners. When a roof is composed of several slopes, with valleys, ridges and verges, the work should be entrusted to professionals.
If you are installing shingles on an existing house, make sure the sheathing (decking), underlayment and eaves protection sheet are all sound, or if possible, new. Flashings and drip edges should also be replaced and installed using the plastic cement for this purpose.
Installation sequence of materials
To begin installation, you need to establish the first row at the bottom of the roof, on the drip edge. Pre-cut starter shingles sold by the manufacturer are fine, or, you can cut the shingle by approximately half of its width. Take care to install the first row in a straight line. On the crest and ridges, shingles are installed perpendicularly. If you are installing laminated shingles, use three-tab shingles for the crest and ridges. For more detailed explanations, consult the step-by-step installation guide.
If you first need to remove old shingles and flashings from the roof decking, use a square roofer’s shovel (with teeth and a bent handle) and crowbar.
New programmes have been introduced to collect and use old and discarded asphalt shingles, primarily for road resurfacing work. Asphalt shingles contain a great deal of bituminous concrete used for asphalt production. Recycled shingles are used as additives to asphalt pavement.
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