Flowing screeds, are a new generation screeding product, They give greater benefits to specifiers and increase design flexibility. These flowing floor screeds are a blend of synthetic calcium sulphate binder, additives, and aggregates mixed with clean water, they offer a great many advantages over traditional screeds.
Using a pumped screed means, a far less labour intensive operation and may generally be laid substantially thinner than conventional materials. Due to the lack of voids, its high flexural and compressive strength, and dependant on the application, 40mm of flowing screed can replace 75mm of conventional material.
Flow screeds are virtually self-compacting and flow easily into place, filling all voids and irregularities. It is precisely levelled by laser to an accuracy of equal to, or better than SR2 floor finish (+ / – 5mm deviation over a 2 linear meter straight edge).
This accuracy can only be achieved by careful preparation beforehand. The screed must be placed with a high degree of accuracy to achieve this requires a large number of tripods placed in the work area to be screeded, so that when the screed is pumped the operative has a clear indication of the amount of screed needed in each area (typically one tripod is used to every 2 square metres) and can pump the screed accordingly. If left to its own devices a pumped screed would not truly self-level due to the aggregate it contains, as this would heap under the surface and leave other areas considerably weaker.
Compared with traditional sand and cement screeds, shrinkage is minimal and is unlikely to occur. Therefore, curling is eliminated as there is no differential shrinkage. It can be applied in all dry locations and in most situations where a conventional bonded, unbonded, floating or heated cement screed could be used.
For floor coverings to be applied, the floor must have reached a certain level of moisture, and this varies from carpet to tiles and vinyl. The floor should be tested to be certain of the moisture level and to avoid problems with moisture in the longer-term, it is suggested that you use a hygrometer for this testing.
After 5 to 7 days the floor may require a light sanding or brushing with a stiff broom to remove any laitance that is left on the surface. It is suggested that you use an epoxy or acrylic sealer / primer before any adhesives are used. The underfloor heating system should have been commissioned as above and then turned off for a full 24hrs before primer is applied.
As an established liquid screed specialist, we are here to provide advice and guidance. Ask us about measuring moisture content; sanding prior to priming; finding the best primer, and much more in Oxford, Newbury, Reading, Northampton, Milton Keynes, and any of their surrounding areas.