Asphalt Shingles Explained: 3-Tab, Architectural and Premium, What the Warranty Says, and What Actually Wears Out

What a shingle is

A fibreglass mat, soaked in asphalt, with ceramic-coated granules pressed into the top to keep the sun off the asphalt, and a strip of heat-activated adhesive on the back that glues each shingle to the one below once the sun warms it. That is every shingle sold in Canada now; the old organic-felt shingles that curled and rotted were phased out around 2010. What changes between grades is how much asphalt is on the mat, how many layers are laminated together, and how good the granules are.

The three grades

The 3-tab is barely cheaper installed because the shingle is a quarter of the price of a roof and the labour is the same. For $100 a square more, architectural shingles last eight years longer and hold on in a wind twice as strong. There is almost no house in Ontario where 3-tab is the right answer anymore, and most roofers no longer quote it unless asked.

The brands, briefly

IKO (Canadian, Cambridge and Dynasty lines), BP (Canadian, Mystique and Vangard), GAF (Timberline HDZ), Owens Corning (Duration), CertainTeed (Landmark), Malarkey (Vista, Legacy, the polymer-modified ones). In the architectural grade they are more alike than different; what varies is the nailing strip (a wider strip forgives a sloppy nailer), the wind warranty terms, and the Class 4 options. A roofer who installs one brand all year installs it well, which is worth more than any difference between the lines. Pick the roofer, then take their brand, unless it is something you have never heard of in a plain wrapper.

What “lifetime warranty” means

Less than it sounds. The manufacturer’s lifetime warranty on an architectural shingle typically covers manufacturing defects only, for as long as the original owner has the house, with full replacement value for the first 10 years and a prorated, shrinking amount after that; by year 20 it pays a fraction of the shingle cost and nothing toward labour or tear-off. It excludes wind above the rating, hail unless Class 4, ice dams, poor ventilation, improper installation, and anything the roofer did. Many of the enhanced warranties (full coverage for 25 or 50 years, labour included) only apply if a manufacturer-certified roofer installs a full system of that brand’s underlayment, starter, ridge cap and vents, and registers it. Ask your roofer whether they are certified and whether the enhanced warranty is on the quote; it is sometimes worth $300 to $600 extra and sometimes a sales line. The warranties page reads the fine print.

What actually wears out

• Granules. They shed from day one and faster after year 15. When the asphalt shows, the sun cracks it in a couple of summers. Bald patches and grit in the eavestroughs are the roof’s calendar.
• The seal strip. It bonds in the first warm weeks after installation and holds the tabs against wind. In old age the asphalt dries out and the seal lets go, and tabs lift. A roof installed in November that never reached 10 C before spring may never have sealed, which is why winter installs get hand-sealed.
• The attic underneath. A shingle on a 60 C attic in July cooks from below. Under-vented attics take a third off a shingle’s life, and no warranty covers it. The single best thing you can do for a new roof is vent it; the ventilation page.
• Nails. Four per shingle on the strip, six in high-wind areas and on steep roofs, driven flush, not through the mat. High nails (above the strip) and overdriven nails are the cause of most blow-offs under the wind rating, and the warranty calls them installation.
• The things around the shingles. Flashings, boots and valleys fail before shingles do. A 25-year roof with 25-year-old chimney flashing leaks at the chimney in year 12.

Class 4 and the hail question

Class 4 is an impact rating (UL 2218): a 2 in. steel ball dropped from 20 ft, twice in the same spot, without cracking the mat. Shingles that pass are usually the polymer-modified ones (Malarkey, IKO Nordic, Owens Corning Duration Flex, GAF Armorshield). They cost $1.50 to $2.50 a square foot more. In Ontario’s hail belt, roughly the southwest and the Niagara-to-Toronto strip, some insurers give a 5 to 15% premium discount for Class 4, which pays for the upgrade in 10 to 15 years; ask your insurer, because it varies by company. Elsewhere, Class 4 is a longer-lasting shingle at a premium price, which is a fair thing to buy if you are staying.

Colour, since you will ask

Dark shingles run a few degrees hotter on the surface and make almost no difference to the attic if it is vented and insulated, which it should be. Light shingles show algae streaks sooner on a shaded north slope; the algae-resistant lines (copper granules) fix that for a few dollars a square. Pick the colour for the house and spend the thought on the ventilation.

Sources and further reading

• IKO: Canadian-made shingles; the warranty and the technical data sheets are on the site.
• BP Canada: shingles made in Quebec; warranty registration is on the site.
• Owens Corning: Duration shingles and the SureNail strip the wind rating depends on.