“Standard” construction practice when laying a new domestic floor usually involves using a concrete base topped with insulation, underfloor heating and screed. Ever on the lookout for ways in which we can improve construction methods we are always looking to innovate new ways to offer benefit to our customers and end users whilst maintaining structural integrity and compliance to building regulations. The usual minimum recommended concrete for house floors containing no embedded metal and which will not receive a permanent finish (e.g. only to be carpeted or tiled) is a Gen 2. This is a designated concrete mix which achieves a characteristic strength of C20. Gypsol XS screed achieves a minimum strength of C30 so is well in excess of the concrete mix used for the same purpose. Gypsol XS screed also enhances the efficiency of an underfloor heating system helping to reduce operating energy costs as well as improving the overall environmental performance of the build.
In this refurbishment project we agreed with floors designer, Screed Manager for Flow Screed Floors Ltd, that Gypsol XS would offer a higher flexural and compressive strength than the originally specified Gen 2 concrete. The proposed floor make up was therefore, well compacted sand blinded hardcore under a minimum 1200guage DPM, under a layer of suitable insulation and a slip membrane followed by underfloor heating and a minimum 50mm of Gypsol XS screed. Having sought and obtained the approval of the building control officers looking after the project, Quadrant AI Ltd, the specification was drawn up and the project confirmed.
The build program was set to allow the general shell to be erected in order to make the structure weather tight using the well compacted hardcore as the temporary working platform. The screed was installed late in the program to help prevent excessive wetting due to rainwater ingress and to avoid construction damage occurring to the screed surface, reducing the need for post build remedial action such as the application of smoothing compounds. Once weather tight the polythene membranes, insulation and underfloor heating were installed followed by the screed at a minimum depth of 50mm.
The underfloor heating was commissioned and once prepared the screed surface was tiled using a gypsum based tile adhesive.
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