Post Installation Guidelines
Lafarge Liquid/flowing screed is a flowing pumpable calcium sulphate based screed designed to provide a smooth level surface in both commercial and domestic applications prior to the application of floor finishes.
Suitable for application to all types of sub floor Liquid/flowing screed is ideal for application as a floating floor on insulation, over underfloor heating (both electric and warm water systems), and cooling systems on thermal insulation and on resilient layers in acoustic applications, for large areas to reinstate the floor level.
Following installation the environment must remain sealed for 2 days. The screed should be protected from direct sunlight and frost during this time. After this period good drying conditions should be maintained, increase ventilation, and if possible increase room temperature to minimise drying time.
Do not cover with polythene.
Storage of materials on the screed surface, accidental exposure to water, humid or cold environments will all delay drying.
After 7 days the screed can be force dried.
When installed over underfloor heating and cooling systems the screed must be heated prior to application of floor finishes. This can commence as early as 7 days after installation, commissioning of underfloor heating should be carried out in accordance with BS1264:2001 Part 4 Clause 4.4 and in line with the manufacturers recommendations, heating should be gradual, in 3—5oC increments and at no time should the water or cable temperature exceed 50oC.
The system should be switched off for a minimum of 48 hours (2 days) prior to determination of the moisture content and installation of floor finishes.
Prior to installation of floor coverings the moisture content of the screed should be determined using the hair hygrometer in accordance with BS8203.
The Contract Flooring Association (CFA) and the Tile Association have recommendations relating to installation of floor coverings on calcium sulphate screeds. These bodies should be consulted for further information.
The surface of the screed should be free from dust, skin or other contaminants and should be sealed with an appropriate primer prior to the application of subsequent adhesives or levelling compounds (consult the manufacturer for suitable products and recommendations for installation).
Both calcium sulphate and cement based products are suitable, however in the latter case the Liquid/flowing screed should be dry and the manufacturers recommended primer used prior to application.
The surface of a Liquid/flowing screed may become damaged as a result of general site traffic or may, although unlikely require making up to the correct datum. In both cases remedial action will be required to make up the screed depth produce a surface that is suitable to receive resilient floor coverings.