How do Ottawa contractors attach metal lath to a steel-framed building for stucco?

Attaching metal lath to steel framing for stucco requires specialized fasteners and techniques that differ significantly from wood-frame construction. Ottawa contractors use self-drilling screws with hex or Phillips heads, typically #8 or #10 gauge, designed specifically for steel-to-steel connections. These screws must penetrate the steel framing by at least 3/4 inch to achieve proper holding power.

The most common approach involves self-drilling tek screws with built-in drill points that eliminate the need for pre-drilling holes in the steel studs. Contractors space these fasteners every 6 inches on center along each stud, with additional fasteners at lath joints and corners. The screws must be long enough to penetrate through the metal lath, any sheathing, and into the steel stud with adequate thread engagement. For typical 25-gauge steel studs with 1/2-inch sheathing, contractors use 1-1/4 inch self-drilling screws.

Proper lath selection is critical for steel-frame buildings in Ottawa's freeze-thaw environment. Most contractors prefer 2.5-pound expanded metal lath or welded wire lath with 16-gauge wire minimum. The lath must be galvanized to prevent corrosion where it contacts the steel framing. Paper-backed lath is often used to provide a moisture barrier, though a separate weather-resistive barrier is still required behind the lath system.

Installation costs for metal lath on steel framing run $2.50 to $4.00 per square foot in Ottawa, which is approximately 30% higher than wood-frame installation due to the specialized fasteners and additional labor time required. The complete stucco system over steel framing typically costs $12 to $18 per square foot for three-coat traditional stucco, with EIFS systems running $15 to $25 per square foot.

Ottawa's extreme temperature swings create unique challenges for steel-frame stucco systems. Steel expands and contracts more than wood framing, requiring careful attention to expansion joints and flexible sealants at building corners and openings. Contractors must install control joints every 144 square feet maximum on steel-frame buildings, compared to 200 square feet on wood frame. The work season remains May through October, with steel framing actually providing some advantages during shoulder seasons since steel doesn't absorb moisture like wood.

Most steel-frame stucco work requires building permits in Ottawa, especially on commercial or multi-unit residential buildings. The Ontario Building Code requires engineered drawings for steel-frame construction, and the stucco attachment system must be detailed in those drawings.

For steel-frame stucco projects, I'd recommend consulting with contractors experienced in commercial and multi-unit construction through the Ottawa Construction Network directory at justynrookcontracting.com, as this specialized work requires different tools and expertise than typical residential wood-frame stucco.