Concrete masonry walls are less affected by the problems associated with moisture infiltration and condensate than other building materials i e.
Moisture in concrete walls.
Concrete is like a sponge absorbing moisture from under the concrete which causes the moisture to come up through the concrete capillaries.
Exterior humid air that enters the basement and condenses on cooler surfaces.
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.
Rising damp usually occurs in masonry.
Interior moisture sources such as humidifiers unvented clothes dryers bathrooms and cooking as well as the moisture in concrete after construction.
The science behind moisture in walls is easy to understand.
So how can you be sure if the walls in a structure have a safe level of moisture.
Moisture supports the growth of mold and causes wall coatings to blister and peel.
Typically this will cause moisture related flooring problems or cause mold and mildew growth.
Some flooring system manufacturers have products that can handle 95 rh or mor 2.
Condensation proves a pervasive threat to buildings especially walls and concrete foundations.
It also saturates insulation reducing energy efficiency.
Controlling moisture in masonry is essential to preserving the integrity of your building projects.
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.
Measuring moisture in walls.
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.
It happens when there s excess moisture coming in and it can t get out of your house.
Corrosion rotting mold delamination blistering and volumetric changes.
How moisture gets into concrete.
Read our tips for concrete moisture testing in the real world to learn more about concrete moisture testing.
In extreme cases moisture intrusion leads to spalling and could even necessitate wall replacement.
Liquid water from rain or ground water.
In commercial buildings the uncontrolled intrusion of moisture into concrete and masonry walls may have costly consequences.
As mentioned above condensation leaks and inadequate drainage are generally the most common causes of moisture issues.