How to read a floor system data sheet

Technical data sheets for resin flooring are written to a common shape, and that shape encourages a particular mistake: comparing two systems figure by figure without asking how each figure was obtained. A number produced under one test condition is not comparable with the same named property produced under another. Reading a data sheet well means knowing which values are properties, which are conditions and which are absent.

Classification and declared performance

Resin screed materials for internal use fall under EN 13813, which sets a designation and a set of declared characteristics. A synthetic resin screed is coded SR, followed by declared classes: wear resistance, bond strength, impact resistance and others depending on the intended use. Compressive and flexural classes appear for cementitious screeds under the same standard. CE marking with a Declaration of Performance under EN 13813 is the document that ties a declared value to a specific product, and it is worth asking for it by name rather than relying on a marketing sheet.

Reaction to fire is declared under EN 13501-1, giving a class such as Bfl or Cfl with an s suffix for smoke production. Where a resin system is used to protect concrete rather than simply to finish it, EN 1504 covers the products and the principles, and the relevant part will be named on the sheet.

The mechanical figures

Compressive and flexural strength describe the cured material as a cast specimen, not as a bonded layer, so they indicate the class of material rather than the performance of the floor. Bond strength to concrete is more useful, but it is bounded by the substrate: a quoted value above the tensile strength of the slab tells you only that the slab will fail first.

Abrasion is usually given by the Taber test, reported as weight loss in milligrams for a stated wheel, load and number of cycles. Those three parameters must match before two Taber figures can be compared. Hardness is generally given as Shore D for rigid resins, which is a useful indicator of resistance to indentation but says nothing about impact or about behaviour at temperature.

Conditions, not properties

Pot life, open time and cure times are conditional values, normally quoted at 20 degrees Celsius and a stated relative humidity. They change substantially with temperature, and a site at 10 degrees will not achieve the quoted schedule. Coverage figures assume a flat, non porous substrate and take no account of a broadcast texture or of profile from shot blasting. Thickness ranges are limits for the system as tested: performance claims apply at the stated thickness.

Chemical resistance tables need the most care. A table normally states the chemical, the concentration, the temperature and the exposure duration, and the result is often graded rather than binary. A blank cell means untested, which is not the same as suitable.

How to interrogate a sheet

• Check that the EN 13813 designation and the Declaration of Performance refer to the product actually being offered, including its primer and wear layer.
• Confirm the fire class under EN 13501-1 and the substrate and thickness it was tested on.
• Note the test conditions beside each mechanical figure, and reject comparisons where they differ.
• Check slip resistance against the finish being supplied, not against the resin alone.
• Read the chemical table for concentration, temperature and contact time, and ask about anything not listed.
• Convert the quoted cure schedule to the temperature the building will hold, and confirm the time to chemical resistance separately from the time to foot traffic.