by Paul Bianchina
When it comes to shingles, there are choices galore. But one of the most attractive from a number of standpoints is the laminated composition shingle. Durable, reasonably priced and compatible with a wide range
of architectural styles, laminated shingles (also called
architectural or dimensional shingles) have long ag
destroyed the notion that composition shingles are suitable only for lower-end housing.
“Composition” refers to the fact that the shingle is made up from a composite of different materials. Most are made up of a flexible and durable fibreglass matt that’s blended with asphalt. The fibreglass and asphalt layers are then topped with mineral granules, which give the shingle its durability, weather resistance and colour. Virtually all composition shingles carry an Underwriter's Laboratories Class A fire rating, which is the highest available. This makes them a great choice for fire-prone areas as well.
The term “laminated” comes from the way that the shingles are layered. Originally, composition or the older plain asphalt shingles were a single, flat layer. Laminated shingles stack two or three layers together on the same shingle, sometimes uniformly, sometimes randomly. The result is a shingle with more shadow lines and more three-dimensional depth, which is considerably more attractive.
The extra lamination also makes the shingle heavier and denser, which keeps the shingle flatter on the roof, reducing its tendency to curl and making it less likely to be affected by high winds. Each shingle has a strip of adhesive on the back, which is softened by the heat of the sun after installation. This allows the upper shingle to bond to the one below it, sealing it down for additional resistance to wind lifting and ice damming.
The combination of heavier weight, fibreglass matting and thicker granule layers also adds to the shingle’s life span and to the length of the warranties offered by the manufacturers. Laminated composition shingles typically offer 30- or 40-year warranties, and some are even higher.
Laminated composition shingles are installed over a base of plywood or OSB sheathing. A base layer of
15-pound felt is laid over the roof sheathing first. In ice-prone areas, an additional ice protection sheet is
installed, extending from the eaves to a point past where the unheated eaves cross over the exterior walls of the house.
A starter course is laid first at the edge of the eaves. The first course of laminated shingles is then installed over the top of the starter course. Each subsequent course is staggered over the preceding course, in a pattern that is set by the manufacturer. This staggering — called “stair-stepping” — ensures that the butt joints in the shingles will not fall directly over the butt joints in the course below.
The shingles are fastened with standard roofing nails or, more commonly, with wide-crown roofing staples shot from a pneumatic staple gun. Full installation instructions, including instructions for valleys, are included with each package.
Accessories and availability
For covering a roof’s hips and ridges, most manufacturers offer matching ridge shingles. These shingles are the same style and colour as the regular shingles
but are precut shorter for fast installation over ridge areas. Ridge shingles can also be cut onsite from regular shingles.
Special ridge vents that match the shingles are also available, or there are universal ridge vent materials that can be installed for ventilation and then covered with ridge shingles that match the roofing.
To complete the installation, some manufacturers
offer accessory paint, which is formulated in colours to match the various shingle colours. The paint can be used for vents, flashings and other rooftop areas to help blend them in with the surrounding shingles.
Laminated composition shingles are manufactured by several different companies. You can see samples at roofing material suppliers, home centres, most lumberyards and some discount outlets. Many of the more popular colours and styles are kept in stock and others are available through special order.
— Inman News.