All you need for checking moisture in flooring is a good moisture meter. You'll need one for wood. And possibly one for concrete, if you have a concrete subfloor to check also. Scientists use the oven-dry testing method to determine the moisture content of wood.
For this test, a calcium chloride disk is placed under a sealed plastic sheet and left to collect moisture vapor. After 24 hours, the disk is retrieved and weighed, and compared to the disk's pretest weight. This weight difference indicates how much moisture vapor has emerged from the slab in 24 hours.
Sometimes, moisture issues show up as an oily, brown liquid or odd looking stains on the surface. This is another indication that the water beneath your flooring is causing issues at the surface. Expert moisture mitigation systems can prevent staining before it grows.
In general, 12% moisture or above is too wet to install flooring. Ideally, it should be between 7% and 9%. Take the readings in at least 20 spots per 1,000 square feet of flooring and average the results. Next, check the moisture of new floorboards.
Use a Reference Scale Meter and Test a “Dry” Sample of Concrete First. Reference scale moisture meters can provide a quick and reliable “wet/dry” indication for concrete. Simply test a bit of concrete you know to be dry with the meter and make a note of the reading given.
Liquid epoxy DPM for existing concrete floors
There are a number of benefits to using a liquid epoxy DPM: An epoxy liquid membrane is applied to the floor itself and creates an impermeable layer meaning that water stays in the concrete slab.
Pinless moisture meters (aka non-invasive moisture meters) are more useful when checking moisture in concrete. Their readings help determine moisture's location and not its content percentage within the material. And like a pin-type meter, a pinless meter's readings merit further investigation.
1. What are the acceptable moisture levels in concrete? Acceptable moisture levels in concrete according to ASTM standard, when testing via ASTM F2170, the RH level of a concrete slab needs to be at or below 75% — unless the flooring system manufacturer provides alternate guidelines.
The rule of thumb is that any moisture reading over 16% is considered damp and needs attention. If your reading is over 20%, you may need to replace the drywall entirely. Walls in homes with healthy humidity levels typically have a moisture reading between 12-15%.
Water will often cause your tiles to become unstable or loose. Hollow Sound: Water-damaged tiles may make a hollow sound if there's a leak. Try tapping your tiles with a coin or other object if you suspect a leak. Staining: If you see any type of staining or discoloration on your tiles, it may be a sign of a leak.
Faulty/Missing Vapor Barrier—moisture from the ground can seep up and through the concrete.
Sealer prevents moisture and other elements from seeping below the surface and negatively affecting your concrete surface.
After thoroughly towel drying the floor, add absorbent material like sawdust, baking soda, or kitty litter. Spread a generous amount of the material over the affected area and let it sit overnight. The absorbent material helps to draw out any remaining moisture from the wood and makes it easier to dry.
You should be aware that a moisture reading of 0-15% is quite normal and gives no cause for concern. However, moisture readings in excess of 15% indicate the need for further inspection. Levels between 25-30% indicate that there may be water ingress, meaning that remedial work could be required.
Zero moisture is not practical or even realistic. Any wood that's been used to frame a house should have a certain amount of moisture. Normal readings should measure around 7 to 13 percent moisture. In fact, slightly higher readings may be normal for your house.
When relative humidity is above roughly 60%, there is a risk of mold growth– with risk really increasing when the RH exceeds 80%. Elevated relative humidity can also lead directly to condensation. When humid air is in contact with a cold surface, it can create moisture or condensation.
Pin type meters cannot read where there are wall or fall coverings such as tile or vinyl. The ReachMaster Pro can penetrate these materials and read moisture from the substrates such as wood and concrete.
The combination of temperature swings and humidity build up cause the concrete to sweat. Concrete sweating, also known as sweating slab syndrome (SSS), refers to condensation that develops on the surface of the concrete. It is directly related to the dew point.
Yes, a high-quality wood moisture meter can be accurate within 0.1% of the wood's moisture content. It also scores high on repeatability, which gives the user confidence that the moisture content readings are spot-on. But it greatly depends on the quality and brand of a wood moisture meter.
The American Concrete Institute (ACI) also recommends a minimum of 10 mil polyethylene or thicker for vapor retarders under concrete. According to its Guide to Concrete Floor and Slab Construction ACI 302.1R-15, thicker poly provides a better barrier and is also more puncture resistant.
A high-quality moisture meter used on the right material can be accurate to within less than 0.1% of the material's moisture content by weight. However, a low-end moisture meter can be wildly inaccurate.