Screed layer: definition, role, and skills

What is a screed layer?

A screed layer is a construction professional specializing in the installation of screeds: the layer of mortar applied to a raw subfloor to create a flat, level surface ready to receive flooring.

This is a distinct trade from that of a mason or a tiler. The screed layer does not work on structural elements or final finishes. They work during the intermediate phase of a project, a stage where errors become impossible to fix once the flooring is installed.

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What they do on a job site

• Assess the subfloor : cleanliness, flatness, moisture levels, and the presence of laitance or debris
• Install preliminary layers : moisture barriers, thermal insulation, resilient underlayment, perimeter edge strips
• Calculate thicknesses based on the type of screed, insulation compressibility, the presence of underfloor heating, and expected loads
• Pour and level, using a laser or screed board depending on the chosen technique
• Position expansion joints and divide surfaces according to best practices
• Monitor drying and indicate when the flooring can be installed

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Three areas of expertise combined

First, mastery of materials. An anhydrite screed, a cement screed, and a lightweight mortar do not behave the same way, do not dry at the same rate, and do not withstand the same stresses.

Next, site assessment. Most defects occur before pouring, due to a poorly diagnosed substrate. Knowing when to refuse to pour until an issue is resolved is part of the job.

Finally, coordination. The screed layer works between the heating engineer and the tiler. Their schedule dictates the others', and an underestimated drying time can disrupt the entire project timeline.

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Screed layer, mason, or tiler: who does what

• The mason builds the structure: slab, load-bearing walls, structural work
• The screed layer prepares the floor: insulation, screed, flatness, leveling
• The tiler or flooring installer installs the final floor covering

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Why choose a specialist

Two factors set a screed specialist apart from a general contractor: adherence to drying times and precision in thickness. These are the two most common causes of cracking and flooring detachment, and they are also the two areas where tight schedules often lead to cutting corners.

Our screed solutions cover all these configurations. The most common pitfalls are detailed in our article on mistakes to avoid before pouring a screed.