Screed is a thin top layer of mix (usually sand, cement, and calcium sulphate) which is laid onto a concrete floor to leave it smooth, level, and importantly to fix it at exactly the same height as the forms or guides that surround the new surface. Properly done screeding results in a perfectly smooth level floor but it is a delicate process to get exactly right and not all screeding is the same; in fact the construction industry recognises that with a number of screeding standards.
Different Screeding Standards
If someone quotes you for 'screeding' then ask them what kind of screeding they mean. Screeding is officially graded into three different categories called SR (Surface Regularity) 1, SR2, and SR3. Floors are rarely perfectly regular and even the most carefully poured concrete floor will set with a pattern of 'waves' to it that can add up to quite a difference in heights across a large area. The job of screeding is to even that out and the degree of evenness is what the SR standards are all about. SR1 is finely screeded to a height difference of 3mm or less over a measured three metres. SR1 is high standard, SR2 is considered normal standard and allows for a difference of 5mm, while SR3 is often referred to as utility standard and allows for a difference of 10mm. We can do all levels of screeding so talk to us about what you need.
The mix of screed is crucial as an incorrect mix will fail and we ensure that with professional screed pumps that force the mix action to ensure the right batch and deliver the screed to the working area via screed hoses. Screed hoses are also the best way to avoid damaging other floor areas, especially delicate ones with underfloor heating, when accessing the area being worked on.
The first step in ensuring that our screed is perfectly level to the required SR standard is to use a laser level to fix our parameters. Screed can then be manually compressed as it is laid to ensure there are not hollows or air pockets in the final mix. That doesn't just ensure that it is level, it also ensures there are no hidden weak spots which could be crucial if the floor is likely to take very heavy work loads.
As we've seen there are different levels of screed and while you may only need SR3 in some utility areas we find that most customers really want the perfect flatness of SR1 – that's why they are looking to screed in the first place. If you've got a screeded floor at a lower SR level and want to upgrade it that may be possible so talk to us about applying subsequent levels. We not only work with traditional screed but also a variety of specialist screeds like latex screed, fast drying screed, and fibre screed to ensure that we can guarantee perfectly flat screed in any situation.