Waffle Raft Slab Building Codes & Rules

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Pier

Waffle Pod

Vapour Barrier

Sand Blinding

Edge Beam

Finished Concrete Floor Level

Timber Frame

Waffle Pod

Full Sarking

Clad Frame

Flashing

Concrete Benchmark

Masonry Veneer

AS 2870:2011, 3.4.1

≥ 300^{AS 2870:2011, 3.4.1}

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)}

Soil

- copy

AS 2870:2011, 3.4.2

110^{AS 2870:2011, 3.4.2}

Soil

Loadbearing Wall

AS 2870:2011, 3.4.1

≤ 1.09m^{AS 2870:2011, 3.4.1}

AS 2870:2011, 3.4.1

85^{AS 2870:2011, 3.4.1}

Industry Recommendation

≥ 450^{Industry Recommendation}

AS 2870:2011, 3.4.1

D^{AS 2870:2011, 3.4.1}

Waffle Pod

AS 2870:2011, 3.4.1

20^{AS 2870:2011, 3.4.1}

Masonry Veneer

Loadbearing Wall

AS 3660.1:2014, 4.4

≥ 75^{AS 3660.1:2014, 4.4}

Soil Classification

Vapour Barrier

Continuous under Beams & Pods^[1]
Turn up to Ground Level at Slab Edges^[2]
Protect from & repair any punctures^[3]

Moisture Control

NCC 2022 V1

All Building Classes

NCC 2022, F1D7 & Part 4.2.8 [2019 F1.10, 3.2.2.6]

May 2023

AS 2870:2011, 5.3.3.2 (a)

AS 2870:2011, 5.3.3.2 (a) (i)

AS 2870:2011, 5.3.3.2 (a) (ii)

AS 2870:2011, 5.3.3.4 (b)

AS 2870:2011, 5.3.3.4 (a)

AS 2870:2011, 5.3.3.4 (c)

NCC 2022 HP, 4.2.8

NCC 2022 Vol 1, F1D7

Construction of Footings & Slabs to comply with NCC^{AS 2870:2011, 5.3.3.2 (a)AS 2870:2011, 5.3.3.2 (a) (i)}
Material
0.2mm thk Polyethylene Film^{AS 2870:2011, 5.3.3.2 (a) (ii)}
Medium impact resistance Vapour Barrier^{AS 2870:2011, 5.3.3.4 (b)}
High impact resistance Damp Proofing Membrane^{AS 2870:2011, 5.3.3.4 (a)}
Installation
Underlay entire bottom surface of Slab & Beams^{AS 2870:2011, 5.3.3.4 (c)}
≥ 200mm lap at all Joints^{NCC 2022 HP, 4.2.8}
Taped or lapped around close-fitting Sleeve of penetrations^{NCC 2022 Vol 1, F1D7}
Where punctured, fully seal with more Polyethylene film & tape

AS 2870:2011, 5.3.3.4 (a)

AS 2870:2011, 5.3.3.3 (c)

Continuous under Beams & Pods^{AS 2870:2011, 5.3.3.4 (a)}
Turn up to Ground Level at Slab Edges^{AS 2870:2011, 5.3.3.4 (a)}
Protect from & repair any punctures^{AS 2870:2011, 5.3.3.3 (c)}

Edge Rebate

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)}

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 Mix

N20 Grade to AS 1379^[1]
≥ 20 Mpa strength at 28 days^[2]
≤ 20mm aggregate size^[3]
100mm slump^[4]
Properly compacted^[5]

Concrete Mix RULES

NCC 2022 V4

All Building Classes

NCC 2022, 4.2.10 [2019 3.2.3.1]

May 2023

NCC 2022 HP, 4.2.10

Concrete to comply with NCC^{NCC 2022 HP, 4.2.10}
Mixing & Delivery
≤ 1 ½ hrs complete discharge from Concrete truck upon Cement hydration unless a retarder is used
Compaction by vibration
To remove air pockets
Improve contact with Reinforcement & Formwork
Enhance durability
Avoid over-vibrating
Slab Edges
Proper finishing & curing of edges improves resistance to moisture damage
Chemical Curing
Determine if surface finish adhesive to be used is compatible with chemical curing methods

NCC 2022 HP, 4.2.10 (a) (i)

NCC 2022 HP, 4.2.10 (a) (ii)

NCC 2022 HP, 4.2.10 (a) (iii)

NCC 2022 HP, 4.2.10 (c)

AS 2870:2011, 5.3.1

N20 Grade to AS 1379^{NCC 2022 HP, 4.2.10 (a) (i)}
≥ 20 Mpa strength at 28 days^{NCC 2022 HP, 4.2.10 (a) (ii)}
≤ 20mm aggregate size^{NCC 2022 HP, 4.2.10 (a) (iii)}
100mm slump^{NCC 2022 HP, 4.2.10 (c)}
Properly compacted^{AS 2870:2011, 5.3.1}

AS 2870:2011, 3.4.2

110^{AS 2870:2011, 3.4.2}

AS 2870:2011, 3.4.2

150^{AS 2870:2011, 3.4.2}

AS 2870:2011, 3.4.1

≤ 1.09m^{AS 2870:2011, 3.4.1}

Pier

For M or H Sites^[1]
Each 3rd internal Beam intersection^[2]

Pier RULES

NCC 2022 V3

All Building Classes

NCC 2022 H1D4 & 4.2 [2019 3.2]

May 2023

AS 2870:2011, 3.4.5

AS 2870:2011, 3.4.5 (a)

AS 2870:2011, 3.4.5 (b)

NCC 2022 Vol 2, H1D4

Footings & Slabs to comply with the NCC^{AS 2870:2011, 3.4.5}
Piers added for moderately (M) or highly reactive (H) sites & without Structural Design requirement if^{AS 2870:2011, 3.4.5 (a)}
Single storey construction, &
Clad Frame or Masonry Veneer Walls
Placed under intersection at each 3rd internal Beam^{AS 2870:2011, 3.4.5 (b)}
N12 additional Top Bar^{AS 2870:2011, 3.4.5 (b)}
Shear Fitments not mandatory^{NCC 2022 Vol 2, H1D4}

AS 2870:2011, 3.4.5 (a)

AS 2870:2011, 3.4.5

For M or H Sites^{AS 2870:2011, 3.4.5 (a)}
Each 3rd internal Beam intersection^{AS 2870:2011, 3.4.5}

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 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)}