Moisture Content Of Concrete Slab

Armstrong recommends conducting a calcium chloride test per astm f 1869 the relative humidity in situ probe test per astm f 2170 or the armstrong 72 hour bond test hygrometer test relative humidity meter placed on floor surface and covered with plastic.

Moisture content of concrete slab.

Testing with either method will tell you how. Pieces of concrete are removed by chiseling or stitch drilling and dried in an oven to constant weight. What you re looking for is moisture condition that s within manufacturer s specifications to accept the flooring product you are going to apply. It is vitally important to test your concrete slab s moisture before installing flooring over it.

Why concrete moisture is tested. Gravimetric this is a direct and accurate method of determining moisture content by weight in the concrete slab. Moisture tests for concrete slabs. The moisture content is then calculated as a percentage of the dry sample weight.

Over time hydrostatic pressure will force that moisture upwards and can cause bubbles in surface treatments and cracks in covering materials that are installed above it. If an effective low permeance vapor retarder material is not installed directly in contact with the underside of the slab the concrete will be exposed to a perpetual source of moisture rising from below. Most concrete moisture meters only check surface moisture. How moisture gets into concrete.

Three methods for testing concrete moisture levels. A definitive test that measures the amount of moisture released from the concrete requires a calcium chloride kit or a relative humidity meter. So you re never going to achieve nor would you want 100 percent dry concrete. Internal relative humidity of concrete slab.

Concrete slabs often have thicknesses measured in feet not inches. If excess moisture is present in a concrete slab when an impermeable surface treatment is installed it will become trapped under that covering.