There seems to be as many problems with condensation from piping; ductwork, windows, skylights, and even walls, as there are with leaky roofs. What’s worse is that a leaking roof usually can be located and repaired. Condensation points tend to be overlooked, ignored, or unresolved. Piping is the most common source of condensation. These cold water, chilled water, or refrigerated lines may be un-insulated or only partially insulated. They should be completely insulated, at elbows, valves, and connection points to stop that drip, drip, drip onto the ceiling. Lurking especially behind walls, condensate collects on floors, soaking wallboard until mold becomes visible.
Air conditioning ductwork can also be a problem. It is not unusual to have fiberglass lines ducts with an aluminum foil covering. If the foil covering is broken or deteriorates due to age, dirt and moisture gets into the fiberglass and soon the duct turns into a mold incubator.
These are often culprits when the office smells moldy or people get sinus troubles and there is no visible evidence of mold growth
Condensate on the interior of windows can also result in mold growth. Water drips to the floor, window ledges, or knee walls, and creates a growth environment. Well-constructed buildings often contain “weep holes” or “weeps” to drain interior water to the outside. These can get plugged during construction or renovation or just get plugged over the years with dust and dirt. They are not easy to open because they are often imbedded in the skin of the building. The same situation often happens with skylights.
Interior walls by themselves may even be sources of condensation. When the space of one side of a wall is warm and the opposite side much cooler, moisture can form on the wall. This is more common in commercial buildings that use metal studs or in residential basements where metal studs are set against damp walls. The metal conveys the cooler temperature better than wood. Insulation seems to be effective in these situations.
Recognizing that condensate may be the problem and not a leaky roof or pipe can be the greater part of the solution. Dealing with condensation through proper and complete insulation or proper drainage is the final piece of the puzzle to a mold-free building environment.