How Surface Regularity of Screed Is Measured

Surface Regularity of Screed is a very crucial measure when it comes to floors. It is the quality of screed that defines whether the floor is compliant with the British standards or not. My name is Andy Parkin and I’m the Managing Director of Speed Screed. Let’s get you on board with the Surface Regularity of Screed.

Surface Regularity of Screed : What Does The Standard Say?

The British Standard has very clear definitions and standards set when it comes to the Surface Regularity of Screed. BS 8203-1:2003 section 6.8.3 has everything you need to know about surface regularity compliance.

Surface regularity is applicable to directly finished bases or leveling screeds. There are three main standards for surface regularity and they are SR1, SR2, and SR3. SR1 is the highest standard, SR2 is medium standard and SR3 being the low or utility standard.

Television studios are a great example of an environment where a high level of surface regularity is required, variations in level would cause issues.  Therefore, this type of project would require SR1.  For around 80% of all project SR2 is the standard, this level of surface regularity is suitable for most projects, and in the absence of a specification becomes the default.

The standard is as follows:

• SR1 plus or minus 3mm over 2m
• SR2 plus or minus 5mm over 2m
• SR3 plus or minus 10mm over 2m

How it’s Measured

The surface regularity is primarily measured with the radius of any curvature and the change in height over a short distance. There is special equipment that can effectively measure the Surface Regularity of Screed. It is easy and it is effective.

According to the British Standard, surface regularity for normal floors is measured by putting a straightedge on the floor, totally flat. Now, the deviations from the straightedge are measure from point to point. A slip gauge is used to measure the deviation from the underside of the straightedge.

According to section 6.8.2 in the British Standard, the maximum deviation from datum allowed is 15mm for large areas.

Surface Regularity of Screed matters the most in small areas. Rooms in a house or any confined area is a good example of such a space. The larger the area, the lower the accuracy level can go. Also, areas close to the door, the line along the walls, etc. require a higher precision.

How Surface Regularity of Screed is Fixed

If your floor is non-compliant with the BS codes, there is nothing to worry about. There are measures that can be taken to fix the issues and make a floor compliant.  This may include grinding down high spots or bringing low spots up with smoothing compounds.

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