With its growing popularity and potential advantages, screed is commonly employed in both the public and private sectors. For varying applications, you can get varied screed options. Each type has its own capabilities and backdrop. In this blog, we’ve mentioned various types of floor screed, their composition, utilisation, and viscosity so you can decide which is ideal.
How Screed Is Composed Of?
The common composting materials of screed encompass sand and cement, with a typical ratio from 1:3 to 1:4.5. Certain elements, such as additives, can be added into their composition to reduce their drying time, enhance robustness, or any other specified feature. Take an instance of the project with time sensitivity. Here, the additive can be utilised to decrease the screed’s drying time, making it suitable for the endeavour.
You can get a better understanding with self-compacting screeds created to be pumped with the help of a hose. Subsequently, they are levelled through a dappling bar for efficient and quick installation in large spaces. However, they require proper maintenance and curing to avoid performance issues.
Enlisting the Types of Screeds Used in Floors
Bonded Screed
As its name suggests, it’s a kind of mix completely bonded with a primer or any other bonding agent. It can be laid at minimum thickness where an unbonded screed is inaccessible. Ideal for challenging spaces and heavy loading, care should be taken for a successful laying process. This practical approach prevents de-bonding and instability, ultimately leading to robust flooring.
Prime Applications
- Seamlessly applied in heavy-loading applications.
- Car parks and driveway constructions.
- Utilised in combination with cast-in water pipes.
Viscosity
- 25 to 40mm.
Floating Screed
A floating screed is installed on the top of the insulation, creating a warming and cosy floor. Due to its diverse thickness availability, this thermally efficient screed can be used in both commercial and residential sectors. The most typical uses include installing underfloor heating systems where acoustic or thermal insulation is required.
Prime Applications
- Ideal for floor insulation.
- Preferably used in floor heating.
Viscosity
- Above 65mm for tightly-loaded floors.
- More than 75 mm for high-footing areas.
Liquid Screed
As the industry standard, liquid screed has become increasingly popular. Known as calcium sulphate or compacting screed, it is simple in preparation. You can use this type of screed floor for an area that is less foot-trafficking observant in between 24 to 48 hours. For a smooth workflow, install the partition or load out the screed after 7 days of installation.
Prime Applications
- Underfloor heating installations.
Viscosity
- 30mm or 40mm, based on whether it’s floating or unbonded.
Unbonded Screed
Unlike bonded screed, unbonded screed is applied to a damp roof membrane, usually on the concrete base top. It serves the best while not contacting the main structure, protecting against shrinkage and settlements. The damp roof membrane also offers a shielding environment for damp rising from the substrate.
But this screed type can cause curling, a vertical distortion of the edges. Due to the viscosity of the screed, moisture content and temperature differences come into play, garbling the corners. To overcome this challenge, follow the minimum specified thickness and let the screed completely dry. Calcium Sulphate can ideally be used here as they are less prone to shrinkage.
Prime Applications
- Perfect for cast-in pipes for UFH.
Viscosity
- A mix of cement and sand is 50mm in thickness.
- Calcium Sulphate mixes are 30mm thick.
Underfloor Heating Screed
So far, we learned about underfloor heating in correlation to other screed types, but this specialised screed is installed over insulation or heating pipes. It helps avoid cold or hot spots by conducting the heat evenly throughout the surface and sustaining heat for a long duration. Certain elements are integrated into insulating panels to get control over the heat distribution in each zone.
UFH screed should be cured properly for 21 days before making it in use. Failing to do this results in cracking, which hinders its functionality. To reduce its drying time, adding additives is recommended.
Prime Applications
- Specified for underfloor heating.
- Can be directly used on the pipes which lack insulation.
Viscosity
- For cement and sand, 53mm and 75mm thick.
- Anhydrite or fibre-strengthened are 50mm in thickness.
- Certain Calcium Sulphate only needs 20mm thickness.
Sectors Ideal for Floor Screeding
Be it commercial or domestic, screed can be best used in a setting with internal flooring. Its most common applications in different sectors include:
- Diverse Commercial Units
- Schools
- Hospitals
- Airports
- Housing
- Soun-Proofing Domestic Properties
Which Screed Suits Your Floor the Best?
Not all screed types are compatible with all floors and environments. It’s crucial to know which type suits your floor the best and what floor type you want for your space before opting for any of them. Some other elements, such as load-bearing capabilities, durability, and surface finish, also affect the choice of screed type.
Typically, sand and cement are the most common type of screed and can be employed anywhere. You can look for the drying time of each type to know which works best and align with your project specifications. For instance, liquid screed mixes are best to use in commercial spaces where business owners can’t wait long for their work operations. Assess the strengths of all screed types and choose the one tailored to your requirements.