Liquid water from rain or ground water.
Moisture in concrete walls.
If you have damp patches bubbling paint crumbling plaster or powdery deposits on wall surfaces close to the floor rising damp is probably the culprit.
It also saturates insulation reducing energy efficiency.
Above grade and below grade water can weaken the structure of a building by causing rotting corrosion and many more moisture induced issues.
Concrete is like a sponge absorbing moisture from under the concrete which causes the moisture to come up through the concrete capillaries.
In extreme cases moisture intrusion leads to spalling and could even necessitate wall replacement.
Controlling moisture in masonry is essential to preserving the integrity of your building projects.
How moisture gets into concrete.
Concrete masonry walls are less affected by the problems associated with moisture infiltration and condensate than other building materials i e.
For example if the temperature in the room is around 80 degrees fahrenheit and the rh is 50 then a safe level of moisture in the wall would be about 9 1 mc.
Exterior humid air that enters the basement and condenses on cooler surfaces.
Corrosion rotting mold delamination blistering and volumetric changes.
Moisture supports the growth of mold and causes wall coatings to blister and peel.
It happens when there s excess moisture coming in and it can t get out of your house.
When you read in a sealer data sheet that the mver needs to be 3 pounds or 5 pounds what that means is the number of pounds of water vapor per 1000 square feet per 24 hours.
There are just three sources of moisture.
Typically this will cause moisture related flooring problems or cause mold and mildew growth.
Condensation proves a pervasive threat to buildings especially walls and concrete foundations.
Read our tips for concrete moisture testing in the real world to learn more about concrete moisture testing.
So how can you be sure if the walls in a structure have a safe level of moisture.
Some flooring system manufacturers have products that can handle 95 rh or mor 2.
The science behind moisture in walls is easy to understand.
Water vapor leaves the surface of a concrete slab at a rate that is called the moisture vapor emission rate mver.
Rising damp usually occurs in masonry.
Measuring moisture in walls.
Interior moisture sources such as humidifiers unvented clothes dryers bathrooms and cooking as well as the moisture in concrete after construction.