What time of year is best to install siding in Ontario?

Late spring through early fall is the working window in this region, and the constraint is the material, not the crew's comfort.

Vinyl and cold do not get along during installation. Below roughly −5 °C, vinyl goes brittle enough that it cracks when cut and cracks when flexed into a lock. Panels have to be flexed to engage the course below, so a brittle panel is a panel that fails at exactly the moment it is being installed. A contractor who offers to hang vinyl in February is telling you something about how they work.

Thermal expansion has to be set for the temperature on the day. Panels are cut with a gap at the ends to allow for movement, and that gap is sized differently depending on whether the wall is being clad at 5 °C or 30 °C. An installer who uses the same gap year-round produces buckling in one season and open joints in the other.

Fibre cement and engineered wood are less temperature-sensitive to install, but sealants, primers and paints have their own minimum application temperatures, and cut-end sealing is not optional on either product.

Tear-off exposes the wall. Once the cladding is off, the sheathing and wrap are open to the weather until the new cladding goes back on. That is a manageable risk on a settled July week and a much less manageable one in a November rain pattern.

Spring books out first. Most homeowners decide over the winter and call in March, so April through June fills early. Booking in late winter for a spring slot gets better scheduling than calling in May.

Late summer into early fall is the underrated window. The weather is stable, crews are past the spring rush, and there is enough season left that a job which uncovers sheathing problems still has time to be finished properly.

Repairs are a different question from installations. A wind-lifted panel in January does not wait for spring, and emergency work gets secured when it happens. But an emergency repair in cold weather is a repair, with the understanding that a proper colour-matched fix may need to wait.

The honest scheduling advice: book the quote in winter, book the work for late spring or early fall, and be sceptical of anyone promising a full vinyl re-clad during an Ontario cold snap.

Written by the team at siding contractor in London, Ontario.