I'll bet most people will never notice if they have mold in their masonry wall system of their home until it is too late. Why? Well the effect is so gradual and occurs over such a long period of time, that most people will never notice the change occurring.
However to the trained professional this problem is usually obvious and can cause damage to your masonry walls which lead to un-necessary repairs. If you can identify this problem before it causes damage to your wall system, you may save yourself some hard earned cash!
This is how to identify if there is mold in the masonry walls of your home and what to do about it.
Stand back from the wall in question maybe 50 'to 75'. Now very casually begin to scan the wall. Do not focus on any given area but just look at the entire wall. You will notice the over all tonal quality to your masonry, in terms of light and color. Every wall is different depending on its location, whether it faces the winning winds or not and if the wall gets plenty of sunshine, so you must look at each wall individually.
Ok. Now that you have the over all color tone in your mind eye let's take a little closer look. Notice the top portion of the wall in particular or where adjoining walls meet this wall. What you are looking for is a graduating darkening of the wall from the top down usually. It may not be obvious so you want to look for darker areas within the tonal range of the wall. If you identify an area that has this darkening effect, then step a little closer for a good visual and to see if you can figure out why that area is darker.
You will notice that directly above the darker portion of the wall will be a shed point of water, such as a termination point for an adjoining wall, roof, masonry or flashing materials. You have to look close and use your 'inspector' glasses because sometimes it may not be obvious. One thing is for sure. The wall would not be darker if there was no mold present.
Remember that mold spores are always present in the air that we breathe. When these spores find damp locations they settle in and begin to multiply. They will not grow without water present. As rain water absorbs into a wall over a period of time then conditions become ripe for a mold bloom.
That is your key to knowing that excess water is entering into your wall system. Once you have identified the mold areas and the probable cause of the water infiltration then it's a simple matter to fix the problem.
Many different repairs could be required depending on the cause, the location and the severity of the problem. Usually it will be flashing, a simple pointing of missing mortar joints, replacing a chimney crown or rebuilding portion of a damaged area.
As you can see there is no 'one fix' for any given mold problem. If the problem seems larger than you want to tackle then contact your local masonry repair expert for his advice, on how to prevent mold build up in your masonry walls.