Liquid Screed Vs Traditional Sand Cement Screed: Which Is Better?
Choosing The Right Screed For Your Project
When undertaking construction projects requiring level floor finishes, selecting appropriate screed material becomes crucial. The choice between liquid screed and traditional sand cement screed significantly impacts project timeline, costs and performance.
Both methods create smooth surfaces ready for floor coverings or underfloor heating. However, their application methods and performance characteristics vary considerably. At Mitchell Plastering & Dry Lining Ltd, our floor screeding contractors have experience with both materials, providing insights into when each performs best.
What Is Traditional Sand Cement Screed?
Traditional sand cement screed combines Portland cement with sharp sand in ratios typically 1:3 to 1:4.5 parts, mixed with water to create workable consistency. Skilled tradespeople spread and level the screed by hand using traditional tools. The material must be tamped and floated to remove air pockets, then finished with steel floats.
This method works well for straightforward applications where time constraints are minimal and budget considerations paramount. It suits garage floors, industrial applications and projects where basic functionality takes precedence.
What Is Liquid Screed?
Liquid screed is a more modern type of flooring surface application. Made primarily from calcium sulphate (gypsum) with water and specialist additives, this material arrives ready-mixed and flows into place.
Application involves pumping liquid screed through hoses directly onto prepared subfloors. The material flows around obstacles, fills gaps completely, and self-levels to create extremely flat surfaces without manual intervention.
Different formulations include fast-drying versions and flexible formulations for underfloor heating applications.
Installation Speed / Efficiency
Differences between installation speeds are dramatic. Liquid screed installation covers up to 2,000 square metres daily, ideal for large-scale developments or tight schedules. Traditional screed requires significantly more time and labour. Typical teams cover 100-200 square metres per day. Each section must be mixed, transported, spread, and finished by hand. For commercial developments where delays cost money, liquid screed's speed often outweighs higher material costs.
Drying Times & Project Scheduling
Traditional screed follows British Standard BS8204 guidelines: 1 day per millimetre thickness for first 50mm, then 2 days per millimetre thereafter. A typical 75mm thick screed requires approximately 100 days to reach acceptable moisture levels.
Liquid screed offers dramatically faster drying. Standard formulations allow foot traffic after 24-48 hours and can be force-dried within 7 days. Fast-drying formulations achieve readiness in 12 hours. These reduced times translate directly into cost savings through faster completion and reduced overheads.
Performance With Underfloor Heating
Liquid screed excels with underfloor heating, offering superior heat transfer and complete pipe encasement. It flows completely around heating pipes, eliminating air pockets that reduce thermal efficiency. Liquid screed requires only 30mm depth above pipes compared to traditional screed's 50mm requirement. This improves thermal response whilst reducing floor build-up height. Traditional screed struggles to fill spaces around pipes. Air pockets remain, creating thermal barriers that reduce efficiency.
Surface Quality
Liquid screed's self-levelling properties consistently achieve extremely flat surfaces, typically meeting SR1 or SR2 tolerances without additional work. This reduces floor preparation needs before installing coverings. Traditional screed quality depends heavily on operative skill and site conditions. Surface tolerances typically achieve SR3 standard, which may require additional preparation.
It is important to note that liquid screed produces laitance (weak surface layer) during the drying process that must be removed before applying finishes.
Making Your Choice
Your choice should consider project size, timeline constraints, budget and performance requirements. Large commercial projects with tight schedules typically favour liquid screed despite higher material costs. Smaller residential projects may benefit from traditional screeding methods.
Underfloor heating applications strongly favour liquid screed due to superior thermal performance and reduced thickness requirements.
Mitchell Plastering & Dry Lining Ltd brings over 20 years of experience to every project. We specialise in both liquid screed and traditional applications, helping select the most appropriate material. Contact us today for expert advice on your floor screeding requirements.
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