FprEN 1937

FprEN 1937 is a CEN draft European Standard for the standard mixing procedures used when testing cementitious and calciumsulfate-based floor levelling compounds. It specifies how to prepare the powder component with water and/or a liquid component supplied by the manufacturer so that later test results are comparable. The document is intended for laboratories and technical users who need a repeatable preparation method before further testing.

What does FprEN 1937 specify?

FprEN 1937 specifies the mixing procedure for cementitious and calcium sulfate-based floor levelling compounds. It is used when these products are prepared as subfloors to provide a homogeneous layer with consistent absorbency, evenness and strength before floor coverings are installed.

The document is organized into eight clauses:

• Scope
• Normative references
• Terms and definitions
• Apparatus
• Materials
• Mixing conditions
• Mixing procedures
• Test report

What are the key requirements of FprEN 1937?

• Clause 4 defines the standard mixer. FprEN 1937 requires mixing equipment in accordance with EN 196-1, with a stainless steel bowl and blade, controlled opposite rotations, and a checked blade-to-bowl gap. In practice, this means the same mixer setup must be used to keep preparation consistent between tests.

• The mixer settings are fixed by clause 4 and Table 1. The document assigns low and high speeds for both blade rotation and planetary movement. This matters because mixing energy affects the prepared mixture and can change test results if different equipment settings are used.

• Clause 4 also requires timing control. A timer with 1 s accuracy is required. This supports repeatable mixing times, which is important when a procedure depends on short mixing and waiting periods.

• Clause 5 controls the test materials. The powder component is sampled in accordance with EN ISO 15605 and prepared in accordance with EN 1067, then kept sealed and dry until use. The liquid component is water and/or the manufacturer’s separate liquid component, with distilled or deionized water preferred unless other water is shown to give the same results.

• Clause 6 sets the conditioning and test environment. All materials must be stored for at least 24 h under standard laboratory conditions from ISO 554, and the test room air circulation is limited. This reduces variation caused by temperature, humidity and airflow.

• Clause 7 gives two mixing procedures. FprEN 1937 provides one procedure without waiting time and another for compounds that require a waiting time before final mixing. The procedure used depends on the manufacturer’s instructions, and the mixture is used immediately after the final deaeration step.

• Clause 8 makes reporting traceable. The test report must identify which mixing procedure was used and the total time elapsed to the end of mixing. For practice, this lets later tests be compared on the basis of the same sample preparation.

What terms does FprEN 1937 define?

• underlayment - a thin layer on a load-bearing substrate that creates a smooth and/or flat surface for floorings and has a uniformly absorbent surface.
• cementitious-based floor levelling compound - a ready-mixed dry mortar whose binder consists mainly of cement and/or cementitious binders.
• calcium sulfate-based floor levelling compound - a ready-mixed dry mortar whose binder consists mainly of calcium sulfate.
• powder component - the floor levelling compound before liquid is added.
• liquid component - the water and/or separate liquid supplied by the manufacturer for mixing.
• prepared component mixture - the compound after the powder component has been mixed with the liquid component.
• set component - the prepared component mixture after it has set.

Who uses FprEN 1937?

FprEN 1937 is used by test laboratories, manufacturers of floor levelling compounds, and quality control teams that need a repeatable sample preparation method. It is also relevant to technical staff working on subfloor preparation and product verification for floor coverings. Buyers and specifiers can use it to understand how test samples for these products are prepared.

What changed in FprEN 1937 from the previous edition?

FprEN 1937 will supersede EN 1937:1999. The foreword states these significant technical changes:

• the former term “hydraulic setting floor smoothing and/or levelling compounds” was changed to “cementitious and calciumsulfate-based floor levelling compounds”
• the scope was made more specific
• the terms “underlayment”, “cementitious-based floor levelling compound” and “calcium sulfate-based floor levelling compound” were added
• the mixing speed in the mixing procedure was added
• editorial changes were made

Which standards are used with FprEN 1937?

What does the FprEN 1937 document contain?

FprEN 1937 contains the apparatus requirements, the material handling rules, the conditioning conditions, and two standard mixing procedures. Figure 1 shows the bowl and blade geometry for the mixer, and Table 1 gives the mixer speed settings. The final clause tells the user what must be recorded in the test report so the mixing history stays linked to any later test.