Roofing warranty: what is actually covered

Two warranties, not one

When someone announces "a 50-year warranty", they are almost never talking about the warranty that matters most. On a new roof there are two, and they cover completely different things.

The first comes from the manufacturer and covers the material: if the shingle itself has a manufacturing defect, that is on them. With us, depending on the product chosen, those warranties run 25 to 50 years.

The second comes from the contractor and covers the installation: if the work was done badly, that is on them. Ours is 10 years on workmanship.

And here is the point I want you to take away: in this trade, the large majority of problems come from the installation, not the material. A defective shingle out of the factory is rare. Badly fitted flashing, neglected ventilation or misplaced nails are far more common. So the workmanship warranty is the one that protects you most concretely.

Who covers what

Four situations, four different answers:

• •Manufacturer warranty (25 to 50 years): covers a defect in the material itself. The length depends on the product installed, and it is often prorated over the years.
• •Workmanship warranty (10 years): covers the quality of the installation — laying, flashing, finishing. This is the one that comes into play in most real cases.
• •Home insurance: sudden damage from a storm or hail generally falls to your insurer, not to a warranty.
• •Covered by nobody: normal wear at the end of the roof's useful life, and damage caused by lack of maintenance.

What can void your warranty

Situations that surprise a lot of homeowners:

• •Attic ventilation that does not meet spec — several manufacturers require it to honour their warranty
• •Work done afterwards by another contractor on the same section of roof
• •Installing new shingles over the old ones, which some manufacturers prohibit
• •Pressure washing, which strips the shingle's protective granules
• •Modifications such as adding a vent or a badly sealed skylight
• •No documented maintenance, in certain specific cases set out in the contract

The "50 years" question and real service life

A 50-year warranty on a shingle does not mean your roof will last 50 years. In Quebec, an asphalt shingle roof generally lasts 20 to 25 years, depending on product quality, ventilation and exposure.

Those two numbers do not contradict each other: the warranty covers a manufacturing defect, not the normal wear caused by our freeze-thaw cycles and our summer sun. After a certain number of years most of these warranties also become prorated — they no longer reimburse the material's full value.

I would rather be straight about that than let you believe the number on the brochure matches your roof's lifespan. It does not, and no serious roofer will tell you otherwise.