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LIQUID SCREED TECHNICAL  DATA 

DESCRIPTION

Liquid Screed is a cement based self-levelling flood coat for levelling floors and can be used for interior or exterior applications. Liquid Screed can receive light foot traffic 24 hours after application and can receive floor coverings after a curing period of 14 days.

The compressive strength of liquid screed at 28 days exceeds most flood toppings and can be used for bonded, unbonded or floating applications. 

Liquid Screed is designed as a flood coat over concrete slabs, beam & block floors, in-situ concrete floors, precast concrete floors and engineered timber floors.  

Liquid screed is a pre-mixed, self-levelling, Pump applied, fibre reinforced screed, delivered to site in a ready-mix concrete truck and pumped into place using specialized Liquid Screed pumps at a rate of 20m3 p/h.

 

BONDED CONCRETE PREPARATION ​

Bonded Liquid Screed application to concrete floors must be solid, clean and free of wax, grease, asphalt, latex compounds, curing and sealing compounds and any other surface contaminants must be removed. Mechanically clean the floor using recommended preparation methods such as shot-blasting, scarifying, diamond grinding, shaving or other suitable methods to provide a roughened, clean, sound, solid and open porous surface. Acid etching is not an acceptable method of cleaning the subfloor. Do not use solvents or sweeping compounds. Subfloors must be dry (AS 1884) and properly primed for successful installation. Subfloor temperatures must be a minimum of 10°C. 

Expansion strips are applied around the perimeter of the installation space and any columns within to provide a gap for liquid screed expansion.

 

UNBONDED AND FLOATING APPLICATIONS

Unbonded, a polyethylene cleavage membrane installed over the existing floor, expansion strips are applied around the perimeter of the installation space and any columns within to provide a gap for liquid screed expansion and movement.

Floating, the screed layer is applied on top of acoustic insulation to create acoustic thermal-insulated floor. This is mostly used in residential properties and in flooring with underfloor heating systems.

Insulation is used to prevent thermal (heat) and acoustic (noise) loss. Approximately 15 – 20% of all household heat loss occurs through the floor.

Increasingly people in Australia are now living in high rise buildings where noise and privacy between units is an important issue. People are now also moving away from traditional carpet flooring to hard floor covers such as tile, timber and vinyl. A change from a soft floor covering (carpet) to hard flooring often creates an adverse noise impact to adjacent and lower residences, this can be overcome using liquid screed in acoustic floor applications for multilevel residential buildings, hospitals, universities, schools etc.

TYPICAL KEY FEATURES AND BENIFITS 

  • Reduced slab section thickness

  • Thinner screed sections compared to traditional screeds.

  • Min 20mm Bonded  

  • Min 30mm Unbonded

  • Min 35mm Floating 

  • Delivered by pre-mixed concrete truck

  • Typical Compressive Strength 49 Mpa at 7 days & 69 Mpa at 28 days

  • Typical Flexural strength of 7Mpa at 28 days

  • Curing time 20mm topping 14 days 

  • Fibre reinforced (no steel required)

  • Typical Minimal Drying Shrinkage 610us at 28 days 

  • Typical Density 2240kgm3 

  • Achieves approximately1-4mm flatness over 2.4m

  • Achieves approximate smoothness of 2mm over 150mm

  • Light Foot traffic 24 hrs 

  • Applications - Bonded / Unbonded / Floating 

  • Complies with AS 3958.1 (thickness requirements) 

  • Complies with AS 1884-2012 (moisture content)

  • Complies with AS1884 (compressive & tensile strength)  

 

TYPICAL ADVANTAGES OF LIQUID SCREED USED IN ACOUSTIC FLOOR APPLICATIONS 

  • Thinner structural slab section of only 150mm, reducing building height requirements 

  • Ready-mix, pump applied, zero silica exposure

  • Thinner topping sections of only 35mm, reducing building height requirements

  • increased acoustic performance compared with sand/cement screeds

  • Fully encapsulating providing great thermal and acoustic performance 

  • Receive light foot traffic after 24hrs

  • High strength 69pma at 28 days 

  • Floor covering installation after just 14 days

  • Application of 20m3 p/h / 1000m2 per day at 35mm, allowing for fast installation

  • 10 x faster than sand cement screed applications

  • Approximately 50% cheaper than engineered sand/cement screeds

  • Achieves levels of approximately 1-4mm over 2.4m and a smoothness of approximately 1-2m far exceeding sand/cement screeds or concrete

  • Zero danger of whipping pipes, Liquid screed pumps operate as a worm pump system at a max 40 psi

THICKNESS OF APPLICATION

TYPE                                  MIN          MAX 

Bonded                         20mm     150mm

Unbonded                    30mm     150mm

Floating Residential     35mm     150mm

Floating Commercial  40mm     150mm

 

TYPICAL TECHNICAL INFORMATION            

Type of Product - Liquid Screed

Strength Grade after 24 hrs - 5 MPa

Strength Grade 7 Days - 49 MPa

Strength Grade 28 Days - 69 MP

Tensile Strength - 7 MPa 

Flexural Strength - 7 MPa

Density - 2240 kg/m3

Drying Shrinkage - 610us 28 days 

Flow Spread - 800mm

Plastic shrinkage control - Yes

Reinforcing fibres - Yes

Curing required - Yes

Curing time 20mm topping - 14 days

Light foot traffic - 24hrs

Delivery - Reay-mix concrete truck

Instillation Method - Pump applied

Flooring compatibility - 99% of flooring adhesives and paint

Silica dust exposure - Zero

Complies with AS3958.1 (thickness requirements) - Yes

Complies with AS1884-2012 (moisture content) once cured - Yes

Complies with AS1884 (compressive & flexural strength) - Yes

 

CURING 

After placing the liquid screed, it should not be subjected to windy conditions, direct sunlight or heating for the first 48 hours, Curing will take 14 days for a 20mm topping before flooring can be installed.

 

JOINTS AND CRACKS

Liquid Screed should not be installed over any moving joints or moving cracks. All existing expansion joints, isolation joints and construction joints, as well as all moving cracks, must be honoured up through the underlayment and flooring. 

Control joints should be incorporated in Liquid screed as with regular cement/sand screeds, the distance between control joints shall not exceed 5.5m in either direction as per AS 3958.1 tiling standards.

Dormant control joints and dormant plastic shrinkage cracks in Liquid Screed greater than a hairline (1/32’’ 0.79 mm) must be pre-filled with a crack or joint filler prior to the installation of the floor coverings. 

Please be advised that while dormant control joints and dormant cracks must be filled prior to installing finish flooring, this filling is not intended to act as a repair method that will eliminate the possibility of joints and cracks telegraphing. 

Liquid Screed is a non-structural material and is, therefore, unable to restrain movement within the substrate. This means that while some dormant joints and dormant cracks may not telegraph up into the finish flooring, cracks will telegraph in any area that exhibits movement in the substrate, such as an active crack, an expansion or isolation joint, or an area where dissimilar substrates meet.

We know of no method in the construction industry to prevent this telegraphing from occurring.

 

FLOOR COVERINGS

Liquid screed is compatible with all floor coverings, and 99% cementitious adhesives, vinyl and carpet glues. The screed's moisture content should be measured after 14 days before placing floor coverings, for glued vinyl and glued carpet tile installation a smoothing skim coat may be necessary.

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