Unlike flowing liquid screeds, semi dry underfloor heating screeds can be accelerated reducing the drying times allowing you to install your final floor finish much earlier.
This type of covering comprises of a traditional mix of coarse sand and cement, usually in a 4:1 ratio. The screed requires enough water to reach a consistency where a handful will clump together when squeezed without producing more than a few drops of moisture.
In most cases, polypropylene reinforcement fibres might be added to reduce the risk of cracking and crazing, or additives incorporated within the mix to offer faster drying times or extra strength. The screed mix is piled into sections of temporary formwork/screed pile of the correct height, before being carefully levelled off with a straight edge and finished with a plastic float and trowel.
Once laid, the exact curing time will depend on the temperature and humidity in the building and the type of screed installed, but traditional mixes will need at least 28 days before the heating can be used.