{"id":20206,"date":"2026-01-30T12:24:07","date_gmt":"2026-01-30T11:24:07","guid":{"rendered":"https:\/\/www.darda.de\/?page_id=20206"},"modified":"2026-01-30T12:24:07","modified_gmt":"2026-01-30T11:24:07","slug":"cement-screed","status":"publish","type":"page","link":"https:\/\/www.darda.de\/en\/knowledge\/cement-screed","title":{"rendered":"Cement screed"},"content":{"rendered":"
\n

Cement screed is a load-bearing, cement-bound screed mortar installed as a flat and durable layer on structural slabs, concrete slab<\/strong> sections, or separation layers. It forms the base for floor coverings in residential, commercial, and industrial buildings and is also used in technical areas where moisture resistance, durability, and controlled load distribution are required. In deconstruction and refurbishment scenarios, cement screed is often selectively removed or adapted\u2014for example, in the course of gutting works<\/strong> and concrete cutting<\/strong> or for subsequent breakthrough<\/strong> openings. Depending on the build-up, adjacent concrete components can be processed with low vibration levels using Darda GmbH tools such as concrete demolition shear<\/strong> or hydraulic rock and concrete splitters<\/a><\/strong> when openings, recesses, or partial deconstruction<\/strong> are required.<\/p>\n

Definition: What is meant by cement screed<\/h2>\n

Cement screed is a screed based on cement as a hydraulic binder, mixed with aggregates (e.g., sand), water, and, if necessary, admixtures. After placement, the mortar is compacted, struck off, and smoothed. It hardens through hydration<\/em> and achieves its final strength depending on the mix design and curing conditions. Cement screed is insensitive to moisture, can be used indoors and\u2014given a suitable build-up\u2014outdoors, and serves either as a wearing layer or as a substrate for coverings such as tiles, resilient floor coverings, parquet, or industrial floor systems.<\/p>\n

Structure and material properties of cement screed<\/h2>\n

Cement screed is typically installed in layer thicknesses of about 40 to 80 mm; greater thicknesses may be appropriate for heated screeds and industrial floors. Its compressive strength<\/em> and flexural tensile strength<\/em> are significantly influenced by the water\u2013cement ratio, aggregate grading, compaction, and curing. Common strength classes follow recognized technical rules (e.g., CT-C25-F4 to CT-C40-F6). When properly executed, cement screed is dimensionally stable and exhibits balanced shrinkage and creep behavior. It is suitable for floating constructions on insulation, for heated screeds with integrated pipe systems, as well as for bonded screeds on sound concrete substrates.<\/p>\n

Construction types: bonded, unbonded (separation layer), floating, and heated screed<\/h2>\n

The choice of construction depends on use, loads, and building physics requirements.<\/p>\n

Bonded screed<\/h3>\n

Screed bonded directly to sound concrete for maximum composite action. It is slim, highly loadable, and used, for example, in workshops or technical rooms. Substrate preparation (milling, shot-blasting, bonding bridge) is crucial.<\/p>\n

Screed on a separation layer<\/h3>\n

Separated from the structural slab with film or cardboard. It limits restraint but is less crack-insensitive than bonded screed. Suitable where varying moisture may migrate from the substrate.<\/p>\n

Floating screed<\/h3>\n

Laid on thermal or impact sound insulation. The standard solution in residential buildings. It requires adequate perimeter insulation strips and a continuous insulation layer to avoid sound and thermal bridges.<\/p>\n

Heated screed<\/h3>\n

With integrated heating pipes or mats. It requires a defined cover over heating lines, a controlled heating-up and cooling-down protocol, and controlled moisture management before installing finishes.<\/p>\n

Standards, strength classes, and layer thicknesses<\/h2>\n

Cement screed is designed according to strength and usage classes. Typical guide values:<\/p>\n