About Screed Flooring
Screed Considerations
Impact and floor loading
Domestic, industrial, and commercial projects require establishing the floor loads and floor traffic types to determine the strength and depth of the screeds needed in the specifications.
Some of these modified screeds can be laid on substrates other than concrete. Latex or epoxy-based products are usually laid as levelling compounds to improve smoothing tolerances, typically for vinyl and fragile coverings.
Material choice
A traditional screed was typically a cementitious material made from a 1:3 to 1:4.5 ratio of cement to sand, a simple sand and cement mix. These provided minimal durability, strength, and low thermal conductivity values. Technical advancements in screed manufacturing allows us to deliver more sophisticated mixes suitable for a broader range of applications.
Some of these modified screeds can be laid on substrates other than concrete. Latex or epoxy-based products are usually laid as levelling compounds to improve smoothing tolerances, typically for vinyl and fragile coverings.
Many modern-day screeds are manufactured to be pumped into place and are designed to be self-compacting and self-curing. They almost all have high flexural strengths and are very durable. Widely used pumped screeds are typically called flowing or liquid screeds, such as Gypsol or Gyvlon.
These usually consist of anhydrite compounds based on a calcium sulphite binder. A specialist contractor must install them and these screeds must be allowed to dry to the required level before floor finishes are installed. We also supply and install cementitious-based flowing, liquid screeds such as Cemfloor. These typically have lower flexural strengths than anhydrite screed but may offer quicker drying times.
Got Questions?
Check out our FAQ page for more information on screed flooring.
Screed thickness and moisture
Construction programmes rarely allow enough time for the evaporation of water in screeds to take place. Typically, anhydrite screeds require one day per 1mm up to 40mm in depth (40 days) and two days per 1mm above 40mm, as a rule, to be dried to 75% RH. The floorcovering installer and/or manufacturer should test the screeds to satisfy themselves as to the suitability and readiness of the screed to receive the floor finish as stated within British Standards.
The drying times required can cause significant disruption to the build process. The moisture content is essential, as most floor coverings are sensitive. Our industry recognises this and manufacturers have developed screeds that chemically control the water content required. This is primarily to reduce the use of a DPC on top of the screed and reduce the impact of high moisture content.
We consider a DPC to be an unnecessary compromise if screeds are considered early in the programming stages of the build. Our optimum screed thickness is from 20 to 50mm, depending on the presence of underfloor heating.
Bonded or Unbonded
Screeds can be bonded or un-bonded (assuming the presence of a suitable subfloor). Bonded screeds are laid directly to the solid subfloor. Usually, a chemical bonding agent is applied before laying to ensure good adhesion. This ensures that the screed acts monolithically with the base. We provide quality control measures during the preparation and laying process to ensure de-bonding does not occur, as this can result in a failed, unstable screed.
Traditionally, thin screeds require bonding. It is rare to see an un-bonded screed of less than 50mm. Due to the advancements in screed technology, we can now offer unbonded screeds such as TS15 at depths of 15mm. These screeds are designed for this type of installation using a specific mix design to ensure high flexural strength. Un-bonded screeds use a damp-proof membrane as a separating layer from the subfloor. This allows placement after the subbase has been laid. However, we recommend curing time for subbase slabs be observed to avoid excessive moisture within the build.
Nationwide Coverage
We have successfully installed a wide range of concrete and screed floors in domestic and commercial properties nationwide, from a single-room extension to complete warehouses.
No screed or concrete flooring assignment is too large or small. No matter your location, you can trust Midland Flooring to deliver high-quality, affordable flooring solutions.
For more information, visit our website contact page and choose the most convenient way to reach us. We value your time and interest and offer a FREE, no-obligation quotation. We believe in providing transparent and fair pricing, reflecting our commitment to your satisfaction, and respecting your decision-making process.
Contact us: call our team on 01675 465 110 or send an email to info@midlandflooring.co.uk
Versatile Options
Environmental Credentials
Flowing-liquid screeds can offer reductions of around 95% in terms of CO2 emissions associated with the screed. In addition, they provide reductions in landfills and improvements in thermal performance with or without underfloor heating. It can be easily seen that liquid-flowing screeds are the perfect choice for any environmentally responsible construction project, helping to achieve BREEAM ratings.
Installation
Midland Flooring can supply and install the insulation membranes, underfloor heating and liquid-flowing screed using our highly qualified, experienced in-house installer teams, enabling us to guarantee the quality of our work (BS EN 8204:7:2003.). Liquid flowing screeds are delivered to the site ready to use via offsite mixing plants, removing the need for labour-intensive site mixing and associated mixing equipment. The liquid-flowing screeds are pumped directly to where needed, eliminating much of the manual handling operations required to install other screeds. All our screeds are pumped using equipment with closed or grilled dispensing hoppers, removing the risk of contact with moving machinery. Our liquid-flowing screed teams finish the surface using a lightweight dappling bar, as this method requires no secondary compaction, thus removing most of the physical work needed to compress other screed types.
Services
Screeds can accommodate services, but we do not recommend placing these into the screed.
We advocate better practices for feeding pipes and cables through a conduit or trucking within the subbase. Re-entrant corners within screeds increase the risk of shrinkage cracking that may reflect through floor finishes. Placing services through the subbase where possible reduces this risk.
Our underfloor heating pipes are encapsulated within specially designed screeds. The pipes can flex with temperature change, but our screeds are unlikely to crack due to this movement, providing the correct underfloor heating procedures are followed when commissioning, even if the screeds have been designed to be relatively thin.
Liquid Flowing Screeds
Self-compacting liquid flowing screeds are made to exact standards by quality-assured manufacturers (according to BS EN 13813:2002.). It combines high-quality binders, specially selected sands, water and special additives where required. It is designed to offer a smooth, flat, and level surface for use in most interior non-wearing applications where a subsequent floor covering is used.
Liquid flowing screed is ideally suited for floating, bonded or unbonded construction and can easily incorporate electric or warm water underfloor heating systems.
