A poured screed (also called a flowing or self-levelling screed) is a screed applied to the structural floor in a liquid state that levels itself almost flat. This self-levelling property makes it possible to produce large, true surfaces quickly, suitable as a base for the floor finish.
Application
Poured screeds are used above all over underfloor heating. The thin-flowing mortar fully encloses the heating pipes, so that the heat is distributed evenly and released quickly. They serve as a base for tiles, laminate, vinyl or seamless resin floors.
Most poured screeds are based on calcium sulphate (anhydrite), occasionally on cement. Anhydrite-bound screeds can be laid in thin layers and large fields without movement joints and shrink very little.
Characteristics
Because the screed is pumped and levels itself, laying is faster than with a traditional, hand-floated sand-cement screed. After pouring, the surface is lightly de-aerated with a spiked roller. Key points are the drying time and the residual moisture content: anhydrite screeds in particular must be well dried before a vapour-tight finish is applied. Anhydrite is moreover not moisture-resistant and therefore unsuitable for wet or outdoor spaces.
Related terms
- screed
- anhydrite screed
- screed floor
- underfloor heating
- seamless floor
- drying accelerator
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