Exterior Cladding near you

The notes below are general. How a cladding performs depends as much on its installation details and the manufacturer's instructions as on the material itself.

The biggest practical split is weight. Fibre cement, engineered wood, metal and wood hang on the wall framing and sheathing, so they can usually replace old siding without structural changes. Full-thickness stone and brick are another matter: they need a ledge on the foundation or a steel support to bear on, ties back to the structure and room for a drainage cavity, which a house originally built for siding usually lacks. Adding them to an existing home often calls for an engineer or designer to confirm the support.

Adhered thin stone and manufactured stone weigh less than full masonry, but they depend heavily on the drainage layer behind them and on flashing and clearances at the ground, roof lines and windows. Poorly detailed adhered veneer can hold water against the sheathing without showing much from outside, so ask exactly how water that gets behind it will drain away.

No cladding keeps out every drop of wind-driven rain. A rainscreen wall accepts that and builds a second line of defence: a water-resistive barrier over the sheathing, a narrow gap formed with vertical strapping or a drainage mat, and the cladding fastened over it. Water that slips past the finish runs down the gap and out at the bottom, and air moving through the space helps both the back of the cladding and the wall dry.

Wood studs let heat through much more readily than the insulation between them, so a wall insulated only inside its frame loses heat through every stud. Rigid or semi-rigid boards installed over the sheathing as a continuous layer cover that framing and keep the sheathing warmer. In the walls section of Keeping the Heat In, Natural Resources Canada notes that significant amounts of insulation can be added from outside because space is usually not a limit, except where lot-line restrictions or limited roof overhangs get in the way, and that vertical or diagonal strapping over the insulation helps, among other things, to reduce thermal bridging.

The same guide says a new air barrier can go on the outside while the existing vapour barrier stays inside, and asks renovators to plan for extending window and door jambs and for vents, electrical service, gas and oil pipes, eavestroughs and downpipes as the wall grows thicker. It also sets out when a new vapour barrier can go over the old wall. That is a moisture decision for the contractor or designer, since the wrong layer in the wrong place can trap water inside the wall.

Walls close to a property line or a neighbouring house face stricter fire rules. Building codes, including the National Building Code of Canada that most provinces adapt, contain spatial separation requirements that can limit window area, call for more fire-resistant wall construction and restrict combustible cladding on walls near a lot line. Wood and engineered wood are combustible, while fibre cement, metal, stone and brick resist fire far better.

The rules depend on the distance, the size of the wall and its openings and the code in force where you live, so switching from brick to wood on a side wall close to the neighbours needs checking with the municipality before materials are ordered. The same goes for thick exterior insulation, which moves the face of the wall closer to the line and adds its own material to the assembly.

Whatever the scope, ask for the wall assembly in writing: membrane, gap, insulation, cladding and flashing details, not just the finish material and colour.

Changing a home's cladding often needs a municipal permit, especially when the material or the look of the facade changes, when exterior insulation thickens the walls or when a wall stands close to a property line. Some municipalities also regulate materials and colours on certain streets or in heritage districts, so ask before choosing. In Quebec, classified heritage properties need authorization from the Ministry of Culture before they are altered, while cited properties and sites fall under municipal control.

In Quebec, cladding work falls under RBQ specialized contractor subclass 7.0, which covers insulation, waterproofing, roofing and siding, while stone and brick veneers fall under the masonry subclasses 4.1 or 4.2. Check the licence in the RBQ registry before signing.