When using liquid or flowing screed for a floor, the treatment of the floor, immediately after pouring and in the following few days, is very important to the integrity and function of the finished result.
Following installation, your flowing screed should be provided with adequate protection from rapid drying or draughts for the first 48-72 hours. Thereafter the building should be kept warm and as well ventilated as possible to encourage the screeds drying process.
Immediately after pouring
Four factors should be considered with drying,
- Room temperature – Elevating the room temperature will assist the screed to dry through improved evaporation.
- Relative humidity – It is important to provide good ventilation (dehumidification) to ensure a low RH is achieved as a high RH can slow the drying performance of the screed. Dehumidifiers can be used as early as 72 hours after the screed has been placed. The optimum moisture for the screed before laying floor coverings is below 75% RH (0.5% moisture).
- Screed temperature – UFH can be commissioned at 7 days, this raises the vapor pressure greatly improving the drying characteristics of the screed. This should be combined with ventilation (dehumidification). After 7 days, you can commission the under-floor heating on the lowest setting for the first 24 hours, then raise at a rate of 5 degrees per day to a maximum of 50 degrees, this must be a controlled increase of the temperature, so as not to allow the screed to suffer from thermal shock. The underfloor heating should be turned off for 48 hours prior to doing the moisture content testing.
- Moisture ingress – Flowing screed should be protected from moisture ingress to prevent rehydration which will delay the drying process.
- The area poured will be suitable for taking light foot traffic at 48 – 72 hours.
Screed drying times
The rate at which flowing screed dries can vary widely, depending on individual conditions. Standard rates for Anhydrite Screed are 1mm per day for the first 40mm, and then ½ mm per day for any further depth. So, a floor of 50mm would take 60 days to dry.
By making sure you know how to properly look after the flowing screed floor, we can help you get the very best from our service and products which will allow you to enjoy the benefits of liquid screed pumping, in Oxford, Newbury, Reading, Northampton, Milton Keynes, and any of their surrounding areas.