Screed Test | Moisture, Datum and Surface Regularity Testing

What it measures: The actual moisture content of the screed, as a percentage, from a sample taken through the full depth of the screed.
How it works: A weighed sample is sealed in a flask with calcium carbide reagent and steel balls and shaken. Moisture reacts with the carbide to produce gas; the gauge pressure converts to moisture content.
When you need it: Before moisture-sensitive finishes such as resin, vinyl, timber and adhesive-fixed coverings, especially on calcium sulphate (anhydrite) screeds and where surface readings are borderline. It’s the preferred method of the Screed Scientist and many proprietary screed manufacturers because it tests the material itself.
Standards and guidance: Acceptable limits come from the screed, adhesive and floor-covering manufacturers. BS 8204 and BS 8203 give guidance on testing and on preparing screeds for floor finishes.
Your report: Test locations marked on a plan, depth, readings, instrument details, date, time, room conditions and photographs.
How CSC helps: We take representative samples, test straight away on site and tell you plainly whether the floor is ready, or what needs to happen before it is.

What it measures: A fast, non-destructive indication of moisture near the surface of the screed, using a Tramex meter.
When you need it: For quick surveys across large areas to find wetter zones and decide where to carry out CM or RH tests.
Standards and guidance: An indicative screening method only; results should be used as guidance, because the meter reads the surface and the screed may be wetter lower down. It is not a substitute for CM or RH testing.
Your report: A moisture map of the area showing relative readings and the locations recommended for confirmatory testing.
How CSC helps: We use Tramex to target testing where it matters, saving time without relying on it for the final answer.

What it measures: The relative humidity of air held in equilibrium with the screed, showing how much moisture the screed is still giving off.
How it works: An insulated hood (hygrometer) is sealed to the screed surface and left to settle before the reading is taken and recorded with temperature and conditions.
When you need it: Where floor covering or adhesive manufacturers specify an RH limit before laying.
Standards and guidance: Acceptable limits come from the screed, adhesive and floor-covering manufacturers.
Your report: Hood locations on a plan, RH and temperature readings, settling time, site conditions (heating, ventilation) and photographs.
How CSC helps: We seal hoods properly, keep conditions steady, test in slow-drying spots (corners, thicker sections, poorly ventilated rooms) and explain what the readings mean for your programme.

What it measures: The soundness (in-situ crushing resistance) of the screed surface, by dropping a standard weight onto the screed and measuring the indentation.
When you need it: Before heavy traffic, MEWPs or follow-on trades load the floor, where a screed is suspected of being weak or poorly compacted, and as quality assurance before handover.
Your report: Test positions, indentation readings, the category achieved against the specified category, and photographs.
How CSC helps: We tell you whether the screed is strong enough for its intended use and, if not, the options for remedial work.

What it measures: Level: how far the screed surface is above or below the design datum level across the floor.
When you need it: Where finished floor levels matter, such as thresholds, lift entrances, door openings, adjoining floors and raised access or tight finish build-ups.
Standards and guidance: Level is not the same as flatness: a floor can be flat but at the wrong level, or at the right level but not flat.
Your report: A grid survey of levels against datum, with readings plotted on a plan and areas outside tolerance highlighted.
How CSC helps: We survey the floor and give clear, plotted results you can share with the design team.

What it measures: Flatness: the deviation of the screed surface beneath a straightedge laid on the floor.
When you need it: Before thin floor finishes such as vinyl, resin and timber, where high spots and dips show through or cause problems, and to confirm a screed meets its specified surface regularity class.
Standards and guidance: Criteria vary by screed and flooring type, so we always test to the particular specification.
Your report: Measurement positions, deviations recorded, the class achieved against the class specified, and remedial recommendations for any non-compliant areas.
How CSC helps: We measure to your specification and, where needed, advise on remedial measures such as grinding or levelling.

Screed Test. Certainty Delivered.