Part of the service offered by Francis Flower Ltd is to provide NBS model specifications, technical and of course practical advice to clients, designers and end users of our products. One of the most common requests is advice on drying screeds prior to installing final floor coverings and one of the major benefits of Gypsol screeds is their ability to be rapidly force dried. Where a screed contains an underfloor heating system this provides the perfect mechanism for such rapid drying as it must be commissioned prior to the application of floor coverings. Commissioning of the underfloor heating can be performed after just 7 days following installation.
This project was specified by Francis Flower Ltd on behalf of the end customer and was thought to need a minimum of 50mm of Gypsol Classic screed allowing a minimum 25mm cover over underfloor heating pipes. During the installation the screed installer found that, due to undulations in the sub floor, the floor required an average of 64mm of screed. This was installed on 14th April 2015. The underfloor heating was commissioned on 21st April and used to force dry the screed. Plenty of ventilation, by means of open windows and doors, was applied in order to remove moisture from the atmosphere above the screed as it was drying. After commissioning was completed, the tiling Contractor tested the screed for residual moisture using a digital hygrometer and found it to be just 56% RH. This allowed the tiling installation to commence on 11 May 2015 just 27 days after the screed was installed.
“Thank you for your advice re our screed. I thought that you might like to know the outcome. The screed was poured on the 14th April with an average depth of 64mm, it was this depth because of a level problem. The screeders gave a very good, helpful and quick service.
As advised we opened all doors and windows and a good breeze flew across the floor. After a week we put the underfloor heating on low and increased it a week later. We tested for moisture daily with plastic sheet which showed a lot of moisture.
After 4 weeks our tiler tested the floor and with two readings it showed an average of 56%. So laying the floor started on the 11th May.
So a very good result and confirms that this screed could be dried with a lot of heat from the underfloor heating.
Thank you for all your help”
John Hope-Hawkins, Nottingham
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