The class of local surface regularity of a directly finished base or levelling screed, if used, should be selected from those given in Table 5 according to the use of the floor. In making this selection, account should be taken of the type and thickness of the wearing screed or flooring to be applied and the standard of surface regularity required of the finished floor.

The highest standard (SR1) should be used where a thin flooring is to be applied and where the minimum irregularity is required of the finished floor, e.g. for a television studio. Conversely, the lowest standard (SR3) may be selected where a thicker type of wearing surface is applied and where the regularity of the finished floor is not a significant factor.

NOTE Insistence on higher standards of surface regularity than are necessary will result in higher costs.

In service, the suitability of a floor in terms of surface regularity is governed by its radius of curvature and changes in height over short distances. Specialist test equipment is now available with which to assess these factors and new specifications may be used to control them. Although this new test equipment is more complex to use than the straightedge, it is less laborious on large floor areas.

The designer should specify the maximum permitted abrupt change in level across joints in direct finished slabs and levelling screeds, taking into account the type and thickness of the flooring to be applied. For some types of floorings, a maximum of 2 mm would be acceptable, taking into account the surface preparation necessary to receive the flooring. For other types of flooring, especially thin floorings, it would be appropriate not to have any changes in level across joints.

Interior Screed Ltd are the UK’s leading floor screeding contractors specialising in all types of floor screeding systems. Established in 2010 and working with many of the biggest and most prestigious names in the residential and commercial building sector’s we install screeds into building developments of all sizes. From complex large-scale commercial projects to residential and mixed-use contracts, we carry a comprehensive range of floor screeding products and services designed to offer our customers a one-stop floor screeding facility.

With 6 regional offices, we are uniquely positioned to provide a local service to our customers throughout the UK, promoting sustainable working relationships.

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