Now available from Longcliffe, a dry powder bulk binder that enables liquid cement floor screeds to be laid and ready for use quicker than anhydrites with no laitance.
Longcliffe Quarries, a lime product specialist based in Derbyshire, introduces Longfloor, a dry powder bulk binder for use in liquid cement floor screeds.
The company says its Longfloor liquid cement screed system has major advantages over both traditional screeds and anhydrite / gypsum flowing screeds in that it can be laid 10 times quicker than traditional screeds with manual handling being avoided and a dense, even surface with a creamy smooth finish achieved.
Longcliffe says Longfloor will cure at three times the speed of anhydrite / gypsum-based flowing screeds, does not have any laitance that has to be removed and eliminates the problems of contamination and blistering than can occur with wet concrete or cement-based floor adhesives.
The product is not susceptible to cracking, crazing or curling and can be used in both domestic and commercial applications. It provides good thermal conductivity over underfloor heating systems.
Longfloor can be applied in up to 25mm thicknesses in bays of 150m2, which means a single crew could lay 1,000m2 in a day.
The binder consists of superfine high-purity limestone powder plus a suite of dry chemical reagents and admixtures manufactured to BSEN 13813:2002. It is made in a new state-of-the-art factory at one of Longcliffe’s quarries near Matlock. It can be delivered by tanker to a stockist's silo for mixing with sand, cement, water and a liquid admixture.
Stockists are typically ready-mixed concrete plants, mixer or dry leg. Delivery to customers can be from drum mixer or volumetric trucks. Longfloor liquid cement screed is discharged (usually, pumped) into a building then simply dappled before applying Longcure, a sprayed proprietary curing agent also from Longcliffe. Longfloor has a certified 95% recycled content.
Andy Littler, Longfloor director, says: "We are very excited about this pioneering, easy-to-use screed product. For many years the concrete industry has tried to develop a cement-based liquid screed that flows well, dries quickly and is not prone to cracking. We have now achieved this. The screed industry is witnessing a sea change in favour of cement-based liquid screeds and we intend to make Longfloor the market leader and top-performing benchmark standard."