Stiffened Raft Slab Building Codes & Rules

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Masonry Veneer

Beam Spacing

Vapor Barrier

Edge Beam

Concentrated Load

Centred beneath steel Column^[1]
SL72 reinforcement^[2]

Localised Thickening RULES

NCC 2022 V1

All Building Classes

NCC 2022, 4.2.20

May 2023

NCC 2022 HP, 4.2.20 (b)

NCC 2022 HP, 4.2.20 (c)

NCC 2022 HP, 4.2.20 (a) (i)

NCC 2022 HP, 4.2.20 (a) (ii)

Centre Slab Thickening beneath Steel Column^{NCC 2022 HP, 4.2.20 (b)}
SL72 reinforcement with ≥ 50mm Concrete cover^{NCC 2022 HP, 4.2.20 (c)}
Concentrated load (see Table for Tiled or Timber Floor & Metal Roof)^{NCC 2022 HP, 4.2.20 (a) (i)NCC 2022 HP, 4.2.20 (a) (ii)}

NCC 2022 HP, 4.2.20 (b)

NCC 2022 HP, 4.2.20 (c)

Centred beneath steel Column^{NCC 2022 HP, 4.2.20 (b)}
SL72 reinforcement^{NCC 2022 HP, 4.2.20 (c)}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 50^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

AS 2870:2011, 3.2.3

≤ 5m^{AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 300^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

Articulated Brickwork

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

300^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

< 1m^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

500^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

100^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

150^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

D^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

Soil Class A, S or M Only

Brick

Veneer

Loadbearing Wall

Slab Thickening

Internal Beam

Loadbearing Wall

Timber Frame

Brick Veneer

Fully Sarked

Slab on Ground

AS 2870:2011, 3.2.3

≤ 6m^{AS 2870:2011, 3.2.3}

AS 3660.1:2014, 4.4

≥ 75^{AS 3660.1:2014, 4.4}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 200^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 150^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 50^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

≥ 300^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}

Concrete Slab Insulation

Under Slab ≥ R2.0^[1]
Slab Edges ≥ R1.0^[2]

Concrete Slab on Ground RULES

NCC 2022 V7

Class 1 & 10a

NCC 2022 HP13.2.6 [2019: 3.12.1.5]

May 2023

NCC 2022 HP, 13.2.6 (5) (b) (ii)

NCC 2022 HP, 13.2.6 (5) (b) (i)

NCC 2022 HP, 13.2.6 (4)

NCC 2022 HP, 13.2.6 (6) (a)

NCC 2022 HP, 13.2.6 (6) (b) (i)

Under Slab
R ≥ 2.0 in climate zone 8^{NCC 2022 HP, 13.2.6 (5) (b) (ii)}
Slab Edges
R ≥ 1.0 in climate zone 8^{NCC 2022 HP, 13.2.6 (5) (b) (i)}
R ≥ 1.0 if in floor heating or cooling system installed^{NCC 2022 HP, 13.2.6 (4)}
Insulation
Water-resistant^{NCC 2022 HP, 13.2.6 (6) (a)}
Continuous over the vertical edges or ≥ 300mm deep^{NCC 2022 HP, 13.2.6 (6) (b) (i)}

NCC 2022 HP, 13.2.6 (5) (b) (ii)

NCC 2022 HP, 13.2.6 (5) (b) (i)

Under Slab ≥ R2.0^{NCC 2022 HP, 13.2.6 (5) (b) (ii)}
Slab Edges ≥ R1.0^{NCC 2022 HP, 13.2.6 (5) (b) (i)}

Slab Edge Reinforcement

NCC 2022 V1

NCC 2022 HP, 4.2.11 (7) (e)

NCC 2022 HP, 4.2.11 (7) (a)

NCC 2022 HP, 4.2.11 (7) (d)

≤ 800mm CTS bar chairs spacing^{NCC 2022 HP, 4.2.11 (7) (e)}
Firmly fixed & supported off the ground^{NCC 2022 HP, 4.2.11 (7) (a)}
Wire chairs with concrete cover & placed on flat bases ^{NCC 2022 HP, 4.2.11 (7) (d)}

Concrete Benchmark

Termite Management

Termite control required for Ground Level floor junctions
≥ 75mm slab exposure above the external finished floor level to allow easy detection of termites^[1]

Durable Notice RULES

NCC 2022 V1

All Building Classes

NCC 2022, 3.4.3

May 2023

NCC 2022 HP, 3.4.3

NCC 2022 HP, 3.4.3 (a)

NCC 2022 HP, 3.4.3 (b)

NCC 2022 HP, 3.4.3 (c)

NCC 2022 HP, 3.4.3 (d)

Permanently fixed to the Building^{NCC 2022 HP, 3.4.3}
Located conspicuously, such as on a Meter Box or the like^{NCC 2022 HP, 3.4.3}
Must indicate
Termite Management System used^{NCC 2022 HP, 3.4.3 (a)}
Date of installation^{NCC 2022 HP, 3.4.3 (b)}
Life expectancy, as listed on approved label^{NCC 2022 HP, 3.4.3 (c)}
Manufacturer's recommendations of future inspections^{NCC 2022 HP, 3.4.3 (d)}

Termite RISK

NCC 2022 V3

Class 1 & 10

NCC 2022, H1D3 & HP3.4.1 [2019 3.1.4.2]

May 2023

NCC 2022 HP, 3.4.1(2)

NCC 2022 HP, 3.4.1 (1) (b)

NCC 2022 HP, 3.4.1

Termite Management System Required if^{NCC 2022 HP, 3.4.1(2)}
Location is identified at Risk of Attack, &
Any Primary Building Element is susceptible
Primary Building Elements are^{NCC 2022 HP, 3.4.1 (1) (b)}
Any member designed to take Loads
Wall, Roof, Ceiling, Floor, Ramp or Stair Framing
Any bracing or other framing members
Materials not susceptible to attack^{NCC 2022 HP, 3.4.1}
Metals
Concrete
Masonry
Fibre-reinforced Concrete
Naturally resistant Timber
Preservative-treated Timber

Termite MANAGEMENT

NCC 2022 V5

Class 1 & 10

NCC 2022 H1D3 & HP3.4.2 [2019 3.1.4.3]

May 2023

NCC 2022 HP, 3.4.2

AS 3660.1:2014, 4.4

NCC 2022 Vol 2, H1D3

Termite Management compliant to the NCC^{NCC 2022 HP, 3.4.2}
Inspection Zone^{AS 3660.1:2014, 4.4NCC 2022 Vol 2, H1D3}
≥ 75mm exposed Concrete Face
Smooth surface, free of Ripples or Honeycombing
Tiling, Render, Vapour Barrier, Flashings, Structures & the like, not allowed to bridge this Zone

AS 3660.1:2014, 4.4

Termite control required for Ground Level floor junctions
≥ 75mm slab exposure above the external finished floor level to allow easy detection of termites^{AS 3660.1:2014, 4.4}

Concrete Cover

≥ 30mm over membrane^[1]
≥ 40mm unprotected ground^[2]
≥ 20mm internal surface^[3]
≥ 40mm external exposure^[4]

Concrete COVER

NCC 2022 V5

All Building Classes

NCC 2022 4.2.11 [2019 3.2.3.2]

May 2023

AS 3600:2018, 4.10.3.2

AS 3600:2018, 4.3.1 (c)

NCC 2022 HP, 4.2.11

Concrete must comply with the NCC^{AS 3600:2018, 4.10.3.2}
Cover for standard Formwork & compaction as per table^{AS 3600:2018, 4.3.1 (c)}
Add thickness where cast against ground
Embedded elements must be protected from corrosion or deterioration^{NCC 2022 HP, 4.2.11}

NCC 2022 HP, 4.2.11 (5) (b)

NCC 2022 HP, 4.2.11 (5) (a)

NCC 2022 HP, 4.2.11 (5) (c)

NCC 2022 HP, 4.2.11 (5) (d)

≥ 30mm over membrane^{NCC 2022 HP, 4.2.11 (5) (b)}
≥ 40mm unprotected ground^{NCC 2022 HP, 4.2.11 (5) (a)}
≥ 20mm internal surface^{NCC 2022 HP, 4.2.11 (5) (c)}
≥ 40mm external exposure^{NCC 2022 HP, 4.2.11 (5) (d)}

Beam Layout

Integral structural grid form^[1]
Reinforcement for Edge & Internal Beam ^[2]
Varies based on Site Class (A, S, or M)

Beam Layout RULES

NCC 2022 V4

All Building Classes

NCC 2022 HP4.2.14

May 2023

NCC 2022 HP, 4.2.14

AS 2870:2011, 5.3.9

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

NCC 2022 HP, 4.2.14

Footings and Slabs must comply with the NCC^{NCC 2022 HP, 4.2.14}
Form an integral structural grid^{NCC 2022 HP, 4.2.14}
10% increase in spacing allowed^{AS 2870:2011, 5.3.9}
If spacing of opposite direction is ≤ 20% than required
If with internal beams^{NCC 2022 HP, 4.2.14}
≤ 4m from external corner to intersection with next internal beam
Use Bottom Reinforcement for deeper Beams (see Tables for Site Classes A, S, & M)^{AS 2870:2011, 3.2.3NCC 2022 HP, 4.2.14}

NCC 2022 HP, 4.2.14

Integral structural grid form^{NCC 2022 HP, 4.2.14}
Reinforcement for Edge & Internal Beam ^{NCC 2022 HP, 4.2.14}
Varies based on Site Class (A, S, or M)

Edge Rebate

Slab Reinforcement

≤ 800mm CTS bar chairs spacing^[1]
Firmly fixed & supported off the ground^[2]
Wire chairs with concrete cover & placed on flat bases ^[3]

Reinforcement Mesh Overlapping RULES

NCC 2022 V1

AS 2870:2011, 5.3.2 (c)

Proper Overlap Trench mesh (Mesh A & B)^{AS 2870:2011, 5.3.2 (c)}
Acceptable Overlapping
≥ 2 bars staggered overlap
Avoids weak spot & distributes load better
Unacceptable Overlapping
Overlapped exactly on top of each other with matching bar ends & joints
Causes stress concentration at one point & can lead to failure

Reinforcement RULES

NCC 2022 V4

All Building Classes

NCC 2022 HP4.2.16 [2019:3.2.5.5]

May 2023

AS 2870:2011, 3.3

Class A & S Slab Reinforcement as follows^{AS 2870:2011, 3.3}
SL82 for Slab ≥ 25m & < 30m
SL72 for Slab ≥ 18m & < 25m
SL62 for Slab > 12m & < 18m
SL63 for Slab ≤ 12m

For Western Australia, with Slabs length < 25m, thickness can be reduced to 85mm with Slab Reinforcement as follows^{AS 2870:2011, 3.3}
SL62 for Slab ≥ 18m & < 25m
SL63 for Slab > 12m & < 18m
SL53 for Slab ≤ 12m

NCC 2022 HP, 4.2.11 (7) (e)

NCC 2022 HP, 4.2.11 (7) (a)

NCC 2022 HP, 4.2.11 (7) (d)

≤ 800mm CTS bar chairs spacing^{NCC 2022 HP, 4.2.11 (7) (e)}
Firmly fixed & supported off the ground^{NCC 2022 HP, 4.2.11 (7) (a)}
Wire chairs with concrete cover & placed on flat bases ^{NCC 2022 HP, 4.2.11 (7) (d)}

Recessed Slab

Recess depth ≤ Slab thickness
≥ 400mm lap length^[1]
Recess depth ≥ Slab thickness
≥ 400mm Steel mesh overlap^[2]

Recess Depth RULES

NCC 2022 V3

All Building Classes

NCC 2022 HP4.2.22

May 2023

NCC 2022 HP, 4.2.22 (1) (a)

NCC 2022 HP, 4.2.22 (1) (b) (i)

NCC 2022 HP, 4.2.22 (1) (b) (ii)

If ≤ 1/2 of nominal slab thickness
≥ 400mm lap length of reinforcing mesh from inside face of the recess^{NCC 2022 HP, 4.2.22 (1) (a)}
If ≥ 1/2 of nominal slab thickness
≥ 400mm overlap of top & bottom reinforcing mesh^{NCC 2022 HP, 4.2.22 (1) (b) (i)}
2 layers of SL72 bottom reinforcing mesh^{NCC 2022 HP, 4.2.22 (1) (b) (ii)}

NCC 2022 HP, 4.2.22 (1) (a)

NCC 2022 HP, 4.2.22 (1) (b) (i)

Recess depth ≤ Slab thickness
≥ 400mm lap length^{NCC 2022 HP, 4.2.22 (1) (a)}
Recess depth ≥ Slab thickness
≥ 400mm Steel mesh overlap^{NCC 2022 HP, 4.2.22 (1) (b) (i)}

AS 2870:2011, 3.5.4

Construction Joint

R10/N10 fitment at 600mm CTS intervals^{AS 2870:2011, 3.5.4}

NCC 2022 HP, 4.2.14

AS 2870:2011, 3.2.3

D^{NCC 2022 HP, 4.2.14AS 2870:2011, 3.2.3}