Floor screed fibres are synthetic fibres that are added to building mixtures such as concrete and screed in order to increase their strength, reduce surface cracking and provide a greater level of integrity to the finished floor. Fibres are available ready mixed or as a separate additive and can be used in any bonded, unbonded or floating floor application.
The most common type of floor screed fibres is used to aid the curing process of traditional sand and cement leveling screeds which have been polymer modified during mixing, with polypropylene fibres added to the solution for additional strength once cured. These products are primarily used in applications with underfloor heating where the screed is required to be thicker than usual allowing heat to breach through without compromising the structural integrity of the floor.
Exploring the Advantages of Using Fibres in Floor Screed
Typical thicknesses of these types of floor screeds are between 60mm and 100mm and at these thicknesses, the risk of cracking is high, especially where movement is likely to occur during the installation of the final floor covering. Traditionally these floor screeds would be laid using a mechanically prepared base but due to the increased risk of cracking and the potential for water ingress a damp-proof membrane is normally installed between the substrate and the floor.
These types of floor screeds are also commonly referred to as ‘pumpable self-smoothing’ screeds and can be delivered to the site in a dry state or ‘pumped’ in to place to achieve the required accuracy of level and surface finish before applying any final flooring system. It is important to note that these types of floor screeds are susceptible to curling which is a deformation of the edge of the screed as it dries, the best way to minimize this is to follow the recommendations and guidance provided by the manufacturer, e.g. BS 8204 Part 7.