Why Test For Moisture Content Of Slab Before Laying Hardwoods

You must test the concrete slab for excessive moisture.

Why test for moisture content of slab before laying hardwoods.

Moisture on the inside of the plastic in the form of dampness or even fogginess indicates the slab is expelling moisture in measurable amounts. Slabs less than 60 days old are generally too wet to install floors. The normal moisture content of wood or emc varies from 7 19 depending on the rh in the air. Concrete slabs and floors can be excellent subfloor surfaces for tile and other floor coverings but too much moisture in the concrete can cause problems with flooring installations.

Testing concrete for moisture astm f2170 stipulates the use of in situ probes to determine the moisture condition of a concrete slab at the time that it will be sealed or covered by flooring material. Flooring specialists can test the moisture content of a wood subfloor using the pinless wood. Before moisture testing begins the concrete slab must be a minimum of 30 days old. Let s look at how moisture affects concrete before moving on to moisture s effect on wood flooring.

Moisture levels can be read with a meter like the wagner mmc 220 this is a pinless meter and allows you to get an accurate reading without sticking pins into the floor and creating pinholes. Qualitative moisture tests electrical impedance test and electrical resistance test moisture meter follow meter manufacturer s instructions. Dry the room and test again optional if moisture appeared on the top side of the plastic dry out the room with a dehumidifier or other method then retest the floor with the plastic squares. But before you begin it s important to understand that moisture measurement and management is crucial to both the concrete slab and also the hardwood flooring.

How to check moisture content in concrete floors. The american society for testing materials astm has several standard tests for measuring moisture levels in a concrete slab. Determining moisture content of both the wood flooring and the subfloor is an important part of quality control in the flooring installation process. How to do a moisture test for concrete slabs.

With summer quickly approaching rising humidity levels can compromise your wood floor installations if not accounted for. Test for dryness new concrete is heavy with moisture and it must be a minimum of 30 days old before moisture testing begins. For woodworkers who build cabinets fine furniture musical instruments dishes toys decorative art boat restoration or various other wood products the acceptable wood moisture content normally ranges from 6 to 8. If your subfloor is above 12 moisture dry out the subfloor before installing hardwood floors.

The hardwood flooring s moisture content mc should be in balance with its surrounding ambient environment to support the. Therefore it s advisable to have a floor tested for moisture content prior to installing flooring or moisture barriers.