Screeds (Concrete) Building Codes & Rules

Substrate Preparation^Informative

• Well compacted
• Repair any defect
• Smooth, clean, dry, & dust / oil free surface
• No sharp edges, back of the shovel finish, nor un-vibrated areas

Floor Screeds

• Compacted to required Levels, Falls & Thicknesses^Informative
• Cure screed according to Manufacturer's requirements^Informative
• Movement joints^{AS 3958.1:2007, 5.4.5.2AS 4654.2:2012, 2.15.2}
• ± 10mm wide
• ≤ 4.5m CTS
• Align with control joints
• Above load-bearing beams or walls

Preparing Screeds^{Manufacturer's Requirement}

• Mix
• 1:3 to 1:5 cement to sand (as per Manufacturer's requirements)
• Batch ingredients accurately (i.e. use bucket NOT shovel)
• Add water strictly as directed

Screed Reinforcement^{Tools™ Best Practice}

• Compliant, non ferrous preferred
• No mild steel
• Locate middle of Screed

Thermal / Acoustic Insulation

Benefits^Informative

• Insulation for energy efficiency
• Acoustic Impact performance

Reinforce if required

65 to 75mm thk Light & Heavy Load Floors^{Manufacturer's Recommendation}

35 to 40mm thk Domestic & Commercial Use^{Manufacturer's Recommendation}

Substrate (Concrete Slab)

M

Membrane^Informative

• Compatible to substrate & bedding / finishes

Adhesive

M

M

Membrane / Polythene

Floor Finish

Floating Screed^Informative

• 35mm thk for Domestic
• 40mm thk for Commercial
• 65mm thk for Light Load
• 70mm thk for Heavy Load
• Laid on acoustic or thermal insulation^{Manufacturer's Recommendation}
• Typically used in residential under floor heating system

Screed Risks & Failures

• Efflorescence
• Debonding
• Curling
• Cracking

Screed RISKS & FAILURES

NCC 2022 V2