Metal Siding Cost in Ontario: Steel and Aluminum Panels, Standing Seam on Walls, Gauges, Dents, Oil Canning and What a House and an Accent Wall Cost Installed

The numbers

The rate carries the panel, the clips or fasteners, the starter, J and corner trim in matching metal, the sheathing membrane and the standard flashing allowance, and the labour. Tearoff, rot, wrap on an old wall and scaffolding sit on top, priced on the siding cost page. Vertical profiles want horizontal strapping on a wood wall, the $2.50 line, unless the system is designed to go flat.

Steel or aluminum

Steel is the one to buy for a wall. It is stiffer gauge for gauge, it dents less, it costs less per square foot of panel, and the galvanized or Galvalume coating under the paint keeps it from rusting for decades. Its weakness is the cut edge: where a panel is cut on site the zinc is gone and the bare steel can show a rust line in a few years if the cut was left facing the weather. A good installer hems the edge or hides it in trim, and touches up the cuts.

Aluminum does not rust, ever, which is why the 1960s aluminum siding on half the houses in Midland is still there, chalky and dented but not rotten. It is also soft. A hailstorm or a ladder leaves a mark in aluminum that steel shrugs off, and it expands about twice as much as steel in the sun, so long panels need more room to move. It still has a place: on a cottage 50 ft from the lake where salt and spray would find a steel cut edge, and on the soffit and fascia, where nobody leans a ladder and the weight matters.

Neither one burns. On the ICF houses I build, where the wall itself will not burn, a steel skin is one of the few claddings that keeps it that way, and the panels screw to the webs at 8 or 12 in. like any siding. The other finishes that suit ICF, with their costs, are in the best exterior finishes for ICF walls.

The two ways a metal wall goes wrong

Oil canning. A flat sheet of metal is never flat. Between the ribs or seams it has a little slack, and in afternoon sun the slack shows up as a wave that runs along the panel, bright and dark, like the side of a tin can. It is not a defect in the metal; it is what thin, wide, flat metal does. It is worse with wide flat panels, light gauges, dark colours, glossy finishes and a wall that is not flat under them. You stop it with narrower panels (12 in. rather than 18), heavier gauge, a striated or ribbed profile that breaks up the flat, a matte or low-gloss finish, and a flat substrate, which means strapping that has been shimmed straight before a panel goes on. A quote for wide, flat, dark, glossy panels at the builder rate is a quote for a wall that looks like a lake in July.

Dents. Metal at ladder height and at the driveway gets hit. Aluminum dents from hail. Light-gauge steel dents from a bicycle. The fix is gauge, and a profile with ribs or a batten every foot or so that stiffens the panel. Standing seam at 24 gauge with seams at 12 in. is about as dent-resistant as a cladding gets short of brick. Builder-grade horizontal aluminum lap at ladder height is a dent waiting for a ladder.

The third thing, which is not a failure so much as a surprise, is the sound. Rain on a metal roof is a thing; rain on a metal wall is not, because the water runs down it. What you do hear is the panels ticking as they warm up and cool down, especially vertical steel in the evening on a west wall. It is quiet and it is normal, and it is worth knowing before the first warm March afternoon.

Standing seam on a wall

The standing seam you see on the accent walls in the magazines is a roofing panel turned sideways: flat pans 12 to 18 in. wide with a raised seam at each edge, clipped to the wall with concealed fasteners so nothing shows but the seams. It is the premium rate, $23 a square foot, because it is 24-gauge, the clips take time, every edge has a formed trim piece and the finish is the PVDF paint that holds a dark colour for 30 years. Vertical is the usual run, so the water drains; horizontal standing seam on a wall is done, and it looks good, and every seam is a shelf, so the detailing at the ends has to be right.

The trim is where the money goes. A metal wall has a starter at the bottom, a cap or flashing at the top, an inside and outside corner at every corner, a J or a receiver at every window and door, and a transition wherever it meets another material. Each of those is a formed metal piece in the matching colour, and on a house with a lot of openings the trim can be a third of the material. That is in the rate on a normal house; on a wall with ten windows in 300 sq ft, expect the installer to price it higher and be right.

Two jobs priced

A 600 sq ft accent in steel on a 2,400 sq ft net wall new house. The front entry and the garage wall in vertical mid-grade steel, board-and-batten profile, 600 at $18 is $10,800. The remaining 1,800 sq ft in mid fibre cement at $18 is $32,400. Cladding $43,200. The whole house in the same steel would have been 2,400 at $18, also $43,200, because the two products sit at the same mid rate; the accent costs nothing extra and the mix is a matter of taste. In standing seam at $23 the 600 sq ft is $13,800 and the house is $46,200, so the premium panel on the accent cost $3,000 more than the mid one, which on the front of a $1.2 million house is a reasonable place to spend it.

A 1,400 sq ft net wall bungalow, 1972 aluminum off, mid steel on. Siding 1,400 at $18 is $25,200. Tearoff of the old aluminum at $2.00 is $2,800 and the bin is $550; the old aluminum has scrap value and a good contractor nets that against the bin. The 1972 wall has no sheathing membrane: house wrap 1,400 at $0.85 is $1,190. Flashing kits on 12 openings at $85 is $1,020. Total $30,760 before HST, $34,759 with. The same house in mid vinyl would be $18,860 before HST, which is the honest comparison: steel is $11,900 more for a wall that will look the same in 2056 and will not have a hole where the mower threw a stone.

What to ask for in the quote

1. The gauge and the finish by name. 26-gauge or heavier for steel on a wall, 24 for standing seam. Polyester finish at mid, PVDF at premium. “Metal siding” with no gauge on the quote is 29-gauge.
2. Panel width and profile, and a sample held up on the sunny wall at 3 in the afternoon. That is when oil canning shows and the showroom is when it does not.
3. Strapping and shimming on a vertical panel, written in, with the straightness checked before the panels go on. Flat panels on a wavy wall are wavy panels.
4. Every trim piece listed: starter, top cap, inside and outside corners, window and door receivers, transitions. The cheap metal quote is the one that will “use J-channel” for everything and let the water in at the top of each window. The flashing details to look for are the same as any siding.
5. Cut edges hemmed or hidden and touched up, and the fastener type: stainless or coated screws with washers, matching colour, never bright drywall screws, which rust and streak in a season.
6. Clearances like any cladding: 6 in. from grade and off any roof surface, with a drip at the bottom so the water does not run behind the starter.

If three metal quotes are far apart, the gauge and the trim count are usually why, and the quote comparison grid lines them up.

Questions people ask

Sources and further reading

• Ontario’s Building Code, Section 9.27 Cladding: the first and second planes of protection, sheathing membrane, flashing at openings and transitions, and the clearances from grade and roofs that every siding and stucco job has to meet.
• Canada Mortgage and Housing Corporation: the Canadian wall-assembly and moisture research behind rainscreens and the second plane of protection.
• ICFPro.ca: the ICF walls, brick ledges and attachment details that decide how cladding goes on an ICF house.