More about UltraFloor Screed It UltraCem further information:
Coverage: Consumption varies depending on thickness of the screed and the dosage of UltraCem. For doses of 250 kg of UltraCem per m3 of aggregate consumption is 2.0 – 2.5 kg/m2/mm of thickness. Consumption rate is dependent on ratio, aggregate type/size and grading used.
UltraFloor Screed It UltraCem Technical Data:
Application temperature (°C) | 5 to 35 |
Density of mix (kg/m3) | 2100 |
Pot life of mix (minutes) | 60 |
Light foot traffic (hour) | 12 |
Application of ceramic tiles (days) | 1 |
Application of natural stone (days) | 2 |
Application of vinyl and wood (days) | 4 |
Application of leveller (days) | 1 to 4 depending on depth |
Strength Properties:
TIME (days) | Compressive Strength(N/mm2) | Flexural Strength (N/mm2) |
---|---|---|
1 | > 8 | > 3 |
4 | > 14 | > 4 |
7 | > 20 | > 5 |
28 | > 30 | > 6 |
Mixing:
UltraCem, aggregates and water can be mixed using mechanical mixers such as, concrete pan mixer, forced action mixer, screw mixer or pressurized screed pump.
Where it is not possible to use a mechanical mixer and mixing by hand is required, it is recommended to thoroughly dry mix the UltraCem with the aggregates. Then adding water in small increments whilst mixing until a “damp earth” mix is achieved, typically 5 minutes. The screed should hold together when formed into a ball.
RECOMMENDED MIX DESIGN FOR GENERAL FLOORING
UltraCem binder: 250kg/m3
0/8mm aggregate: 1750kg/m3
Water: 100kg/m3
Note: Water addition may vary depending on moisture content of the aggregate being used.
All test data is based on using the 0/8mm aggregate. If it is not possible to obtain the specified 0/8 aggregate, then 0/4mm aggregate can be used instead. See below for specific mix designs.
TYPICAL SCREED MIX DESIGN USING (0/4MM) AGGREGATE
ISCR BS 8204-1 Cat A – 100kg ULTRACEM: 360kg (0/4mm) Aggregate
ISCR BS 8204-1 Cat B – 100kg ULTRACEM: 500kg (0/4mm) Aggregate
Light foot traffic : 24 hours
Full Traffic: 7 days
Drying Time: 7 days per 25mm (in good conditions)
UltraFloor Screed It Ultracem APPLICATION
All correctly prepared substrates are suitable for receiving an UltraCem modified screed. All screeds should be installed using good concrete practice e.g. incorporating expansion joints where required, day joints and steel rods where required.
For unbonded screeds (minimum of 35mm thick) Isolate the substrate with a polyethylene sheet or similar. For rising damp provide a suitable waterproof membrane. The mix must be spread, tamped and levelled as soon as possible ( must be within hour of mixing). When floated, should provide a closed smooth surface without bleeding.
For floating screeds (minimum of 55mm thick) the screed is applied as above for unbonded screeds. Where underfloor heating pipes are present, there should be a minimum of 25 mm of screed above the pipes. The underfloor heating may be commissioned after 4 days.
For bonded screeds (minimum of 10mm thick) the substrate must be dry, sound and solid, free from cracks, dust, loose material, oil, paint, wax and traces of gypsum. Apply UltraScape pro-prime slurry primer onto the substrate and apply the UltraCem modified screed whilst the primer is still wet e.g. wet on wet. If the primer dries out it needs to be re-applied.
The UltraCem modified screed is applied in the same way normal screed is applied.
PRECAUTIONS
- Do NOT mix UltraCem with other cements or binders
- Do NOT dry mix with aggregate and leave
- DO NOT overwater UltraCem screed
- DO NOT add water or re-agitate the screed once setting has started
- DO NOT use fine sand only – use aggregate grading as in BS EN 13139 (0/8) or (0/4) if not available
- USE the UltraCem screed as soon as it is mixed.
CURING AND DRYING
All curing and drying times are based on good site conditions i.e. an air temperature of 20°C, air humidity of 65% RH and good ventilation. Sites that are cold, humid or damp or in areas where the airflow is poor, will prolong drying and curing times, so allowances should be made accordingly. Applications to non-absorbent substrates and at thicker application depths will take longer to dry.
STORAGE
Store in a dry place at temperatures between 5°C and 35°C.
SHELF LIFE
If stored correctly and used within 8 months of the date shown on the bag, the reducing agent activity will be maintained and this product will contain, when mixed with UltraFloor UltraCem, no more that 0.002% (2 ppm) soluble Chromium (VI) of the total dry weight of the cement. Shelf life in correctly sealed bags is 8 months. Please note: the use of this product after the end of the declared storage period may increase the risk of an allergic reaction.