Ronafix Pre-packed Underfloor Heating Screed 40mm is a pre-bagged mortar which provides a high strength screed. The increased strength of the screed allows it to be laid in thin section, from 40mm, which in turn ensures improved thermal output from the underfloor heating system saving money on energy consumption. Ronafix Pre-packed Underfloor Heating Screed 40mm+ also dry faster than conventional sand : cement screeds meaning the commissioning process can begin earlier (after only 7 days) and can also be opened to foot traffic after 24 hours.