Are you getting ready to have the shingles on your roof replaced? Before signing a contract with a roofer, read our technical backgrounder.

Types of shingle

Compared to traditional felt-reinforced asphalt shingles, new fibreglass-reinforced shingles are lighter and more resistant to heat and curling. Care must be taken, however, when installing them in colder temperatures, as they are more fragile when the temperature drops below 5°C.

A fibreglass shingle can be made of a single layer (the traditional three-tab shingle) or more (the thicker laminated or architectural-style shingle). The latter is better suited for roofs with steeper slopes.

Shingle manufacturers’ warranties

  • The thicker and heavier the shingles are, the more durable they should be, and the longer the warranty will be.
  • The refundable portion of the shingles’ cost will decrease over time until the full term of the warranty is reached.
  • Some warranties cover only the cost of materials.
  • If the shingles are installed incorrectly or attic ventilation is insufficient, this may void the warranty.

Components of the roof covering

  • Decking (sheathing): Where boards were used in the past, either plywood or oriented-strand board (OSB) sheets are now used for decking. The usual thickness is 1/2 in., but 5/8 in. is recommended.
  • Drip edge: Installed all around the roof edge to allow water to run off and drip clear of the outside wall.
  • Underlay (overhang): This usually consists of a self-adhesive membrane designed to prevent infiltration due to ice build-up on the roof overhang.
  • Underlay (entire roof): 15-lb roofing felt or synthetic membrane that helps hide irregularities in the decking and provides extra protection against infiltration.
  • Starter strip: A row of single-thickness shingles laid with their bases pointing toward the ridge, or a membrane with granule coating. Must overhang the drip edge by at least 1/2 in.
  • Valley or junction flashing: Self-adhesive membrane and/or galvanized steel or coated aluminum sheeting that protects areas exposed to water, snow and ice.
  • Ventilation: Vents installed at or near the roof ridge, and perforated soffits. If “Maximum”-type vents are used, any gable vents must be blocked.
    • If the roof pitch is 4/12 or more, the ventilation openings must equal at least 1/300 of the area of insulated ceiling (e.g., 3 ft 2 in. for a 900 sq ft house), with 55% of openings at the bottom of the roof and 45% at or near the roof ridge.


Ask for detailed written estimates from two or three different contractors. Both the estimate and eventual contract should include:

  • The contractor’s name and address, Régie du bâtiment du Québec (RBQ) licence number, and GST and QST tax numbers.
  • Your address and the start date of the work.
  • A detailed description of the work and materials required: o Protection of the premises;
    • Removal of the existing roof covering and transportation of debris;
    • Repairs to the decking;
    • Modifications to the attic ventilation, if required;
    • Reinstallation or replacement of flashing and drip edges;
    • Composition of underlays, type/model of shingles;
    • etc.
  • The terms of billing for any additional work (unforeseen work or extras): hourly rate, cost of materials, authorization procedure, etc.
  • A fixed or per-square-foot price in case adjustments to the decking are required (e.g., new nails, replacement). Standard practice is for the contractor to include repairs over an area of 32 sq ft at no extra charge.
  • Clear indications of the duration of the warranty and any conditions.
  • The total cost of the work and the terms of payment (e.g., deadlines, instalments).

You should also:

  • ask the contractor to provide the name of the civil liability insurance provider and the amount of coverage, and then verify this information;
  • obtain proof that the contractor has a clean record with the Commission des normes, de l’équité, de la santé et de la sécurité du travail (CNESST).
  • demand references.

Contractor’s warranty on labour

  • Minimum requirement of the Civil Code of Quebec: five-year warranty for a complete shingle replacement.
  • Extra five-year warranty provided if the contractor is a member of the Association des maîtres couvreurs du Québec (cost of warranty depends on the value of the work).

In you have any doubts, and before you sign anything, always question the contractor. You can also consult CAA-Quebec’s Residential Advisory Services.