What You’re Attaching To
Every substrate behaves differently. As GC, your role is to verify the substrate is ready, and to ensure your subcontractor provides proof of capacity before installation begins.
- Concrete Substrates: Require 25 MPa minimum strength. Verify anchor locations against shop drawings. If specified, insist on pull-out test reports before proceeding. Confirm surfaces are clean of oils/contaminants before WRB or sealant application.
- Masonry Substrates: Verify CMU thickness and grout continuity. Shelf angles must be engineered and anchored to carry cladding dead loads. Mortar integrity affects both structure and water performance — require inspection reports before cladding starts.
- Steel Frame Buildings: Confirm stud gauge (16 ga min), spacing (400–600 mm), and sheathing type. Require shop drawing verification of deflection track details. Alignment tolerances stack quickly — require survey/laser verification and, for complex façades, laser scanning.
GC Checklist: Demand substrate readiness sign-off by the responsible trade and include anchor test reports in submittals.
Mounting Hardware — What GCs Must Review
- Thermal Spacers: Material type (FRP, polyamide, HDPE) and depth (25–100 mm).
- Rail Systems: Extruded aluminum rails with drainage slots; verify slotted connections for expansion.
- Clip Systems: Fixed, sliding, and spring clips. Require engineered details.
- Fire Compliance: Ensure the full assembly has NFPA 285 compliance or equivalent Canadian certification.
Reveals and Visual Lines
- Maintain consistent reveal spacing within 2 mm.
- Depths of 10–25 mm depending on panel thickness and design intent.
- Align reveals with mullions and floor lines.
- Include reveal dimensions in QC documentation.
Sealing Systems
- Primary Seals: EPDM gaskets or silicone/polyurethane. Verify compression ratios (25–35%).
- Secondary Seals: Backer rod, sealant, and bond breaker tape to avoid three-sided adhesion.
- Maintenance: Require documented maintenance schedule from subcontractor at handover.
Insulation Requirements
- Mineral wool for fire resistance (required in most ACM façades).
- Polyiso for high R-value per inch.
- XPS for moisture resistance at select details.
- Continuity around penetrations and transitions with no compression gaps.
- Include insulation continuity verification in QC closeout package.
GC Oversight Checklist for Mounting Systems
- Anchor pull-out test results reviewed and approved
- Substrate readiness sign-off submitted
- Mounting system documentation includes spacer, rail, clip details, and NFPA 285 compliance
- Reveal dimensions and alignment included in QC reports
- Sealant compatibility and maintenance schedule provided
- Insulation continuity verified and documented
