Sand and cementitious materials are blended according to an appropriate mix design to create a floor screed, which is then used to create a levelled surface for the floor finish that is added to the surface of the floor screed. In some cases, portland cement is used for the added benefits of strength, durability, wet cracking and thermal cracking resistance, and better cohesion.
Floor screed serves as the foundation for floor finish and has a significant impact on how well it performs.
Even though trowelling on the cement sand mixture might seem like all that is involved in screeding, it actually involves much more. It is one of the most important flooring procedures and is essential to the overall flooring's quality, finish, and durability.
Cement, clean sand, and water are the typical materials used in floor screeding. There are different types of sand used in construction. You must choose the right one based on your requirements as it is an essential component for screeding.
Moreover, polymer materials, metal mesh, or glass additives are occasionally incorporated into the mix to reinforce the screed.
UltraTech Floorkrete is a polymer-modified cement, specially formulated for multipurpose floor screeding applications. It is best suited for terrace areas, residential and office building floors, commercial projects, and as underlayment for tile adhesives.
Based on the requirements, applications, and functionality of the floor, you’ll find mainly four different types of floor screed :
As the name suggests, unbonded screeds are not bonded directly to the base. Instead, they are applied to polythene/ Damp Proof Membrane which is placed on top of the concrete base.
If you’re looking for a thickness of standard screed greater than 50mm, this should work best for you. There are also a few modified concrete screeds available for thinner applications.
By slurrying bonding to the concrete substrate, you bond this type of concrete screed with the substrate. It is ideal in situations where a heavy load is expected and a thinner application is required.
The thickness of bonded screeds ranges between 15mm to 50mm.
Using insulation in a floor build up has become quite the trend in today’s modern times. Thanks to this, the option of the floating screed has increased in demand.
A floating screed is normally applied on top of a layer of insulation, a slip membrane over it separating the insulation from the screed. This slip membrane is usually a sheet of polythene, keeping the insulation and the screed separate.
Heated screeds are designed to provide the best solution for your underfloor heating systems since they are flowable in nature. They also have some notable pros in comparison with sand and concrete floor screeds.
The flowable features of heated screeds allow complete coverage of the underfloor heating pipes.
A floor that has been screeded improperly can easily become damaged later on, even to the point of splitting apart and requiring you to start the tedious job again. So, it is vital to be well-prepared for the task, if you are to do it yourself, even before prepping the floor for screeding.
There are several steps you must follow in the process of screeding in construction :
First, you divide the floor you wish to screed into sections. Use long and straight pieces of timber that are of the height of the layer you’re going to screed. Make sure these pieces are wet and can be easily removed later.
Using a trowel to spread the screed mixture out and a screed board or straightedge to compact it, start by covering the section furthest from the room's entry with a levelled coating of screed mixture. Use a tamper to smooth off the edges and finish screeding the area.
You will need a levelling compound if your screed isn’t self-levelling. A piece of timber or a straightedge can be used to level the surface. Put it over the timber pieces that you’re using as dividers, push it forward, tilt it so the corner acts as a cutting edge, and move it side to side to saw through the material.
If your screed is self-levelling, it likely already has a levelling compound mixed in it. It reacts when the screed is poured, causing it to compact on its own.
Repeat the entire process till all the sections of the concrete or sand screed floor are complete. Next, remove the timber dividers and fill in the gaps left behind.
You should be able to remove any faults in the new screed layer as soon as it is installed and once more after the concrete has bled properly.
If left untouched under a polyethylene sheet sealed at the edges, a screed layer takes approximately seven days to cure. It also depends on the layer and size of area that has been screeded.
Once the floor has been cured, it needs at least another three weeks to dry. It is best to avoid installing any other layer of flooring on top during this period.
1) What is a floor screed ?
Floor screed is a thin layer of material, typically made from cement, sand and water, that is applied to a concrete subfloor to provide a smooth and level surface.
2) How long does it take for floor screed to dry ?
The drying time for floor screed can vary depending on several factors, such as the thickness of the layer, the temperature and the humidity. In general, it can take anywhere between a few days to a few weeks for the screed to fully dry.
3) How thick should the floor screed be ?
The thickness of the floor screed depends on several factors, such as the type of flooring being installed, the subfloor condition, and the load-bearing requirements. A qualified professional can recommend the appropriate thickness for your specific situation.
In addition to knowing what a floor screed is, you require the proper training and equipment to be able to carry out the procedure. To avoid any possible mistakes and delays in the installation procedure, it is best advised to bring in professionals to do the job.