Complete Siding Guide for Canadian Homes

What this page covers, and what you need before you start

Use the calculator here to model quantities and compare scenarios with your own numbers, and use this section to control the parts of a re-clad that determine whether the wall performs. Gather the following first.

• Measured wall areas by elevation, less openings, plus linear metres of trim, corners, and soffit.
• Existing cladding type and age, and whether an older material may contain asbestos or lead paint.
• What is behind the cladding, if known: sheathing type, weather-resistive barrier, and any strapping.
• Evidence of water entry: staining, rot at sill plates, interior wall damp, or window perimeter damage.
• Window and door details, since re-cladding is the moment to correct flashing and sill pans.
• Exposure: prevailing wind-driven rain, roof overhang depth, and height above grade.
• Whether insulation is being added outboard of the sheathing, which changes the wall's drying direction.

Decision workflow

1. 1

   Test before you disturb anything on an older house

   Cladding, sheathing paper, caulking, and paint on older homes can contain hazardous materials. Testing before removal is cheaper than stopping mid-project.

2. 2

   Find out why the wall is being re-clad

   Appearance, damage, or a known water problem lead to very different scopes. If there is damage, open a test area and document what is behind the cladding.

3. 3

   Decide the drainage and drying strategy

   Whether the new assembly is direct-applied or drained and vented behind the cladding is the single biggest performance decision, and it must be in the contract.

4. 4

   Detail the openings

   Sill pans, head flashing, and the sequence of the weather-resistive barrier around windows and doors are where most wall failures begin. Require the sequence in writing.

5. 5

   Confirm permits and inspections

   Re-cladding, adding exterior insulation, or altering openings is commonly permitted work. Ask your building department what applies and keep the closed permit.

6. 6

   Photograph every stage before it is covered

   Sheathing condition, barrier laps, flashings, and strapping. Those photographs are the only evidence that survives the finish.

Questions to ask, and records to keep

Ask every cladding contractor the same set, and require written answers with the quote.

• What is behind the existing cladding, and what will you do if you find rot or wet sheathing?
• Is the new assembly drained and vented, and how is that achieved?
• How will window and door openings be flashed, and in what sequence?
• What weather-resistive barrier is specified, and how are laps and penetrations handled?
• Is hazardous material testing required before removal, and who arranges it?
• Which permits apply, who applies, and who arranges inspections?
• What allowance is carried for concealed damage, and how are extras priced?
• What photographic record of concealed work will I receive?

Primary sources for the rules that vary by jurisdiction

Requirements come from provincially adopted codes and your municipality; hazardous material handling has its own federal and provincial guidance.

• National Research Council Canada — Codes Canada publications

  Establishes: The model construction and energy requirements provinces adapt, including the structure of the National Building Code that your municipality enforces.

  Canada (model code, adopted with amendments by each province) · Source link checked 2026-09-01

• Your municipality's building department (permits, inspections, and closed-permit records)

  Establishes: Whether the work you are planning needs a permit, which inspections apply, and whether past work on the property was permitted and closed.

  Municipal · Source link checked 2026-09-01

• Canada Mortgage and Housing Corporation (CMHC)

  Establishes: Federal housing research and homeowner guidance, including maintenance and moisture-management material.

  Canada (federal) · Source link checked 2026-09-01

• Natural Resources Canada — energy efficiency for homes

  Establishes: Federal guidance on home energy performance, EnerGuide home evaluations, and which retrofit programs are currently operating.

  Canada (federal) · Source link checked 2026-09-01

Every source cited across the site, with what it does and does not establish, is listed in the home cost source ledger.

Where to go next

• Windows and doors

  Ratings, condensation, and how installation quality drives outcomes.

• Insulation analysis

  Where the envelope loses heat and what evidence supports an upgrade.

• Water damage guide

  Sequence for finding the source, drying, and documenting a water event.

• Repair cost planning

  Turn an inspection finding into a scoped, quotable repair item.

• Permit requirements

  Which work is permitted work, and why closed permits matter at resale.

• Home cost source ledger

  Every primary source used on this site, the date its link was checked, and what it does not establish.