WHAT IS FLOOR Screeding?
What Is Screeding?
Screeding is a type of concrete used to form a level surface. It is used to either receive floor finishes, to encase underfloor heating pipes or to be left as the wearing surface (specialist types can be left without a floor finish).
Furthermore, it can be laid either on top of an existing concrete base, a damp proof membrane (DPM) or insulation. On top of insulation can be with or without underfloor heating (UFH) pipes. It is very important to ensure the base preparation is correct as it will have consequences for the long-term quality of the screed.
What is FLOOR SCREED MADE OF?
Now that you know what screeding is, you will need to know about screed ratios. The screed mix generally consists of sharp sand, cement, and water. The standard mix ratio is a 1:4 mix design.
HOW IS SCREED MIXED?
Screed needs to be mixed using a forced action to ensure that it is correctly batched. This should be done with a pump. A screed will fail if the mix design is incorrect, or it has not been mixed correctly. Generally, this is when a cement mixer or ready-mix is used. (Ready-mix is only workable for approx. 4 hours, and it can take approx. 6 hours to lay an area).
The screed pumps also transport the mix to the working area via hoses. This ensures that underfloor heating pipes are not damaged in the process which is a common complaint when using a wheelbarrow. As a well-established screeding company, we are always able to provide a pump for your project.
How IS SCREED INSTALLED?
To begin, we survey the space with a laser level. We take measurements for the screed depth required (datum) and transfer this across the space. If there are any issues with the levels, we will discuss different solutions. Crucially we ensure that this level is applied to the middle of the floor and not just the perimeters - this is a rare practice in our industry.
Furthermore, when laying the mix, we manually compact it to expel any air. Because this helps prevent voids, hollows and further strengthens it. This is also not a common practice in the industry, but it is a method our screeders are trained to do. Consequently, if you hammer test our work, it flies off the floor as it is so strong!
WHAT ARE BONDED, UNBONDED AND FLOATING SCREEDS?
Screed can be installed in three methods:
Bonded Screed - screed is applied directly to a existing sub-base such as a concrete slab or block and beam base. Please ensure that the sub base is dry before the screed is laid as any damp will travel through to the screed and any floor finishes in turn especially if the concrete slab has been laid on top of a plastic membrane . The a primer may be required to bonded the screed to the existing base.
Unbonded Screed - the screed is separate from the substrate by a membrane or liquid DPM.
Floating Screed - screed is laid over insulation with or without underfloor heating
What is SURFACE REGULARITY?
Significantly, we lay our screed to the highest standard of surface flatness, which is an SR1 finish (SR stands for surface regularity). This means a perfect surface for your floor finishes – the whole point of having a screed laid don’t you think? If you are quoted for a SR2 or SR3 finish, please think again.
It will cost you more money and time on levelling compounds, latex or additional adhesive to try and rectify the levels. We are so confident of our abilities that we guarantee to provide you with an SR1 finish, and your floors will be perfect.
HOW LONG DOES SCREED TAKE TO DRY?
Screed drying times vary, depending on the type of screed laid, the thickness of the screed and the ambient temperature whilst the screed is drying. Also different floor finishes require different drying times such as a wooden floor or a resin floor which are very moisture sensitive and how soon after screeding that these finishes will be laid. With are expertise we can direct you to the right screed for your requirements
Need Expert Screeding Services?
Call us today about your domestic or commercial project on 020 7099 6264 and we’ll be happy to help.