ICRI CSMT key terms

The stabilized relative humidity inside a sealed concrete slab hole after the material has equalized with the surrounding pore air, expressed as percent RH at a stated temperature and reported per ASTM F2170.

A field procedure that drills holes to a specified depth, lines them with a sleeve, seals the top, and inserts an electronic humidity sensor to measure internal RH after equilibration.

Standard test method for determining relative humidity in concrete floor slabs using in-situ probes; it specifies hole diameter, depth, conditioning time, sensor accuracy, and reporting.

The required depth of the drilled test hole below the slab surface and the minimum time the sealed hole must sit before measurement, allowing the hole to reach moisture equilibrium with the concrete.

A field test that seals a dish of hygroscopic calcium chloride to the slab surface and measures the mass of moisture absorbed over a set period, reported as emission rate.

Standard test method for measuring moisture vapor emission rate of concrete subfloor using anhydrous calcium chloride; defines specimen preparation, exposure duration, weighing, and calculation.

The mass of water vapor leaving a concrete surface per unit area per unit time, typically expressed in pounds per 1000 square feet per 24 hours under the calcium chloride test conditions.

The tendency of calcium chloride emission results to be influenced by the exposed dish area and slab conditions, so results from kits of differing dimensions are not directly interchangeable.

A handheld electrical instrument placed on the concrete surface that infers moisture content from electrical impedance, capacitance, or resistance changes, giving relative rather than absolute values.

Standard guide for preliminary evaluation of comparative moisture conditions of concrete slabs using non-destructive electrical impedance or capacitance meters, intended for screening rather than acceptance.

Standard test method for determining relative humidity on the surface of concrete floor slabs using a sealed insulated hood enclosing a humidity sensor, measuring near-surface conditions.

A procedure that places an insulated enclosure with a humidity sensor against the slab surface and seals the perimeter, allowing trapped air to equilibrate with the concrete surface.

A measurement whose value is meaningful mainly when compared with other readings from the same instrument on the same slab, not as an absolute moisture content.

The humidity of air immediately above or trapped against a concrete surface, which reflects near-surface drying conditions and can differ from internal slab humidity.

Water held within the capillary and gel pores of hardened concrete, which drives internal relative humidity and moves by diffusion, capillary flow, and vapor transport.

The movement of water through fine interconnected pores driven by surface tension, drawing moisture upward or laterally through concrete and toward drier zones.

The mass ratio of water to cementitious material in a concrete mix; higher values increase porosity, permeability, and the amount of free water available to evaporate.

A measure of how readily fluids pass through concrete under a pressure gradient; it depends on pore structure, cracks, and mix design and controls moisture migration rates.

The controlled maintenance of moisture and temperature in fresh concrete to allow cement hydration; proper curing lowers porosity and reduces later moisture release.

The period after concrete placement during which excess water evaporates before a moisture-sensitive floor covering is installed; it depends on thickness, mix, curing, and environment.

The state in which water movement within concrete and between concrete and its surroundings has stabilized, so measured humidity or emission values no longer change materially over time.

A sheet or coating placed beneath or on a slab to limit water vapor movement; when below the slab it reduces upward moisture drive from the subgrade.

The general movement of water vapor through a material driven by vapor pressure differences, distinct from liquid water flow and often expressed as a rate.

Timing moisture tests after concrete has reached a representative condition, after curing and cleaning, and before floor covering installation, while allowing the required sensor conditioning period.

The ambient temperature, humidity, ventilation, and building enclosure status present during testing and drying, which influence measured values and must be documented.

The process of choosing moisture tests based on slab type, floor covering requirements, project stage, and whether quantitative internal RH or surface emission data is needed.

A documented layout defining the number and location of test points to represent the slab, including areas of different thickness, exposure, or construction history.

The complete record of methods, instruments, calibration, test locations, conditions, readings, and deviations that allows results to be verified and interpreted later.

The formal presentation of test results including method standard, units, test locations, dates, ambient conditions, instrument data, and any limitations or exceptions.

The reasoned comparison of measured moisture values with specification limits and product requirements, accounting for method differences, variability, and site conditions.

The verification of instrument accuracy against known references at defined intervals, with records kept to demonstrate that measurements are traceable and trustworthy.

The maximum moisture condition, stated as RH or emission rate, at which a flooring or coating manufacturer permits installation of its product over concrete.

Floor coverings such as resilient sheet, rubber, wood, and some coatings that can be damaged by trapped moisture, including adhesive failure, blistering, cupping, or mold growth.

A product or assembly, such as a topical vapor barrier or self-leveling underlayment, applied to reduce moisture emission before installing a moisture-sensitive floor covering.

A situation in which an inspector's financial or personal interests could bias test results or reporting; it must be disclosed and managed to preserve objectivity.

Acting within one's competence, following applicable standards, maintaining impartiality, and communicating results honestly, including acknowledging uncertainty and method limitations.

A documented record tracking test samples, instruments, or data from collection through reporting, supporting integrity and traceability of results.