A definitive test that measures the amount of moisture released from the concrete requires a calcium chloride kit or a relative humidity meter. Testing with either method will tell you precisely how much moisture is present, making it possible to choose surface flooring that is appropriate.
When measuring moisture in concrete, the best and most reliable method is to use the ASTM F-2170 testing method. Under this method, you'll use a thermo-hygrometer with in-situ probes, along with a series of prepared holes, to get readings of relative humidity deep in the concrete slab.
Damp from the ground can make its way into your concrete floor. Due to concrete's porous nature, it can then travel through it, causing issues in the flooring above. Changes in the surrounding environment can have a major impact on moisture levels within the concrete slab.
Concrete Moisture Barriers can be applied to concrete surfaces in order to protect the surface coating from damage. A good quality Concrete Moisture Barrier, like Moisture Proof, helps to eliminate moisture travelling to the concrete surface.
Use your home or office dehumidifier to dry out the affected space, especially if the humidity level is above 50%. Create air movement. To speed up the drying process, place fans in the affected room close the doors. The air movement will help dry out the concrete.
Sealed concrete will stop releasing moisture. At that point, the slab has the moisture it will hold for the long term.
The easiest solution for damp proofing concrete floors is to install a plastic membrane. Essentially, this is a plastic mesh sheet specially formulated to ensure that moisture cannot penetrate. It sits between the concrete and the underlay floor covering.
Porcelain tile is arguably the very best material for chronically damp locations, provided the grouted seams are maintained adequately. Cracked grout seams can provide an avenue for moisture to seep down into the subfloor.
When it rains, water is absorbed into the ground until the earth is too saturated to soak up any more water. At this point, the water will begin to rise to the surface, causing hydrostatic pressure to build up against your foundation and basement floors, which leads directly to water seepage into your home.
Moisture meters that are calibrated specifically for concrete provide instant and precise quantitative measurement of the moisture content of concrete.
Concrete typically takes 24 to 48 hours to dry enough for you to walk or drive on it. However, concrete drying is a continuous and fluid event, and usually reaches its full effective strength after about 28 days.
Use a dehumidifier placed at the highest setting possible to dry the floors. Place it in the center of the room and leave it on for at least 24 hours. Next, place fans around the room so the entire surface receives the blowing air. Place the fans at the highest settings possible.
If concrete gets too wet it causes excess shrinkage during the drying process. As a result, the concrete is prone to cracks that can be large enough to damage the structure. While cracks are a problem, the real issue with watered down concrete is weakness.
Concrete is a naturally very porous material and water can rise up or travel through capillaries which can lead to damp floors and mould issues. The easiest problems to isolate and repair with damp-floors are issues with above-ground services, such as leaking pipes.
The reason for this is that concrete is a very porous material meaning that water can rise through capillaries and therefore lead the property to suffer from having damp floors.
When you use concrete sealers and coating you add a protective layer to the surface. This layer prevents water and moisture from penetrating the surface. Dry surfaces are less inviting for mold and mildew.
Sealing your concrete not only ensures your concrete surface is protected, but that it is long lasting. It should also be noted that compared to the cost of replacing a concrete surface, sealing is relatively inexpensive and easy to do–definitely worth a long lasting concrete floor, patio, slab, or driveway.
3.5 to 4.5 % Moisture Content.
Excess water at the surface can also weaken the concrete and cause dusting to occur when it dries. Mold – Wet conditions are a breeding ground for mold and bacteria. This can erode concrete and damage the integrity of the floor.
Humidity—warm and humid air condenses into surface moisture when it comes into contact with the cool surface of your concrete floor or slab. Faulty/Missing Vapor Barrier—moisture from the ground can seep up and through the concrete.
Use dehumidifiers and air conditioners, especially in hot, humid climates, to reduce moisture in the air, but be sure that the appliances themselves don't become sources of biological pollutants. Raise the temperature of cold surfaces where moisture condenses. Use insulation or storm windows.
Concrete that is not moist-cured at all dries too rapidly, and reaches less than half its potential design strength. It will also have a greater number of shrinkage cracks.
A 'slump test' involves filling a cone of freshly mixed concrete on a hard, non-absorbent surface and testing how it subsides or slumps. An expert can check if the mix is too wet by measuring the slump and identifying the shape the concrete settles into once the cone is removed.
Moist curing is a common method of concrete curing. It involves wetting the concrete slab often with water (5-7 times per day) for the first 7 days. This method ensures your concrete slab will be extremely strong and durable, because it allows the moisture to evaporate slowly, preventing cracks and shrinks.