Blockwork Masonry Wall (FRL) Building Codes & Rules

All Building Classes

NCC 2022, Specification 1, Specification 5 [2019: Sch 5:1, Spec C1.1:1]

May 2023

• Masonry building elements be constructed to NCC Specification 1, AS 3700, & AS 3600
• Walls Spanning One Way (Vertically)^{AS 3600:2018, 5.7.4.2 (a) (i)}
• Using wall slenderness ratio, Horizontal Chases where
• ≤ 4x the wall thickness, or
• 0.4x the overall wall (L)
• Walls Spanning Two Ways (Panels)^{AS 3600:2018, 5.7.4.2 (a) (ii)}
• Vertical Chase length
• > ½ of the wall height
• Horizontal Chase length
• > ½ of the wall length
• Reduced Slenderness Ratio based on the remaining Wall thickness at the bottom of the Chase
• Permissible Chases
• Walls Spanning One Way (Vertically)
• Vertical Chases^{AS 3600:2018, 5.7.4.2 (b) (i)}
• Horizontal Chases with a length ≤ ^{AS 3600:2018, 5.7.4.2 (a) (iii)}
• 4x the wall thickness, or
• 0.4x the overall wall (L), whichever is greater
• Walls Spanning Two Ways (Panels)^{AS 3600:2018, 5.7.4.2 (b) (ii)}
• Vertical Chase length
• ≤ ½ of the wall (H)
• Horizontal Chase length
• ≤ ½ of the wall (L)

All Building Classes

NCC 2022, Specification 1, Specification 5 [2019: Sch 5:1, Spec C1.1:1]

May 2023

• Concrete building elements be constructed to NCC Specification 1, 5, & AS 3600
• Chases that affects Integrity & Insulation^{AS 3600:2018, 5.7.4.3 (b)}
• Any chase not meeting the "Permissible Chases" criteria
• Calculate based on the remaining Wall thickness at the bottom of the Chase
• Permissible Chases^{AS 3600:2018, 5.7.4.3 (a)}
• ≤ 30 mm Chase depth
• ≤ 1000 mm² Chase cross-sectional area (perpendicular to the Wall)
• ≤ 100,000 mm² Total Chase area on both sides of the Wall in any 5 m² area 
• Calculate Slenderness Ratio based on reduced thickness^{AS 3600:2018, 5.7.4.3 (b)}

• Structural Adequacy^{AS 3600:2018, 5.7.4.2}
• Integrity & Insulation^{AS 3600:2018, 5.7.4.3}