Constraints

• Durability Class 1 per AS 5604 but rated for above-ground use only without preservative treatment — in-ground contact requires H4/H5 treatment
• High density (~900–1100 kg/m³) makes long boards heavy for cladding; boards over 3.6 m typically require two-person handling
• Premium supply cost $80–180/m² installed — approximately 2–3x the cost of equivalent pine cladding profiles
• Tangential shrinkage ~8–10% means only seasoned timber (MC <15%) per AS/NZS 2796 is suitable; green timber risks significant movement and cupping
• High Janka hardness (9.1 kN) makes machining and nail-driving difficult — carbide-tipped tooling required; standard HSS blades blunt rapidly
• Combustible softwood — BAL-29 maximum per AS 3959 without additional fire protection systems; not suitable for BAL-40 or BAL-FZ zones as-supplied
• Limited availability of clear/select grades — knots, gum veins, and interlocked grain are common in standard grades; select-grade stock commands significant price premium
• External surfaces require regular maintenance coating (oil or stain) every 2–3 years to prevent surface checking, UV greying, and moisture ingress
• Regional supply variability — sourced primarily from NSW/QLD; longer lead times and transport costs for Victoria, SA, and WA projects