On Your Side
August 10, 2006
Special Advisory: How to Avoid Mold and Moisture Problems
Water, in several of its many forms, flows into, under and onto most of our houses on a constant basis. Plumbing pipes wind through the house, hidden behind walls.
Excess bathroom humidity gets vented in one direction. Tubs, sinks and toilets drain in another.
The home's heating, cooling and ventilating system quietly controls indoor humidity for optimal comfort, year in and year out.
The house sheds rainwater and snow off the roof, through downspouts and gutters.
Groundwater moves under or around the foundation walls.
The structure itself absorbs and releases moisture vapor and condensation across the seasons.
In a well-built and maintained house, water is a comfort and a health-sustaining element that presents no problem. But, if water, in any of its forms, isn't properly managed, or if your home's water management systems aren't properly maintained, not only will your home lose value - it can lead to serious expense, health problems, structural damage, and the loss of valuable personal property.
Watchfulness and regular maintenance are a homeowner's keys to preventing moisture and mold problems from developing in the home. Use these handy checklists to go room-by-room and check for the tell-tale signs of undesirable moisture intrusion.
If you see any of the warning signs, take steps to have the source of the problem eliminated immediately. Some jobs are easy and you can do them yourself. Others may require additional help by a professional to assess or repair.
Either way - don't procrastinate! Have moisture problems repaired immediately. The longer you wait the more expensive and possibly even damaging the results will be.
Moisture Damage Warning Signs In the Kitchen
Moisture damage can begin in lots of areas of this high-use room!
Around and Under the Kitchen Sink Look For:
Around the Dishwasher Watch For:
Under and Behind the Refrigerator Look For:
Moisture Damage Warning Signs In the Bathroom
Around the Toilet Look For:
Around All Plumbing Lines Watch For:
Around the Exhaust Fan Look For:
Around and In Showers and Bathtubs Look For
Moisture Damage Warning Signs In the HVAC System
It's easier - and less expensive - to prevent moisture damage in or resulting from your heating, ventilating and air conditioning system that to repair it. Here's what to keep an eye on.
What to Look for in the Heating System
What to Look for in the Cooling System
Moisture Damage Warning Signs In the Utility Closet
A room that contains a water device, such as a water heater, deserves looking into regularly.
Moisture Damage Warning Signs In the Attic
You may not go into the attic very often, but it's worth the trip because so many expensive water damage problems start at the roof!
Around the Attic Vents Look For:
Around Recessed Lights Look For:
At All Roof Penetrations Look For:
In the Insulation Batting Look For:
In Attic HVAC Systems Look For:
Moisture Damage Warning Signs In the Laundry Room
By definition, laundry rooms are warm and moist. Small wonder it's a prime location for moisture and mold problems. If you spot any of these warning signs, take steps to correct them.
What to Look for at Hose Connections
What to Look for at the Dryer
Moisture Damage Warning Signs In the Basement
It pays to keep a sharp eye out for uncontrolled moisture or water stains in the basement. It can help you detect developing water problems in other parts of the house, including gutters and bathrooms. In addition to being a breeding ground for mold, damp basements also attract unpleasant things such as bugs, rodents and snakes!
Moisture Damage Warning Signs On the Exterior of Your House
Watch Out for Poor Drainage
Watch Out for Trees
What to Look for in the Windows and Doors
What to Look for in Siding and the Walls
Mold and Mildew
General Subject Information: Mold and mildew (fungi) and the spores by which they reproduce are present everywhere in the environment, including indoor air and surfaces of buildings. Usually the small numbers of these tiny organisms do not cause any problems. However, high levels of moisture combined with organic materials provide conditions that can result in their rapid growth. In high concentrations, some of these fungi may consume wood and other building materials sufficiently to cause decay and rot. Others may produce stains and unattractive coatings on interior and exterior surfaces. Some people can develop allergy-like symptoms if exposed to mold. While it is quite difficult (if not impossible) to entirely eliminate these organisms in normal residential environments, control of interior humidity and preventions of leaks limits their growth and minimizes any resulting affects.
There are thousands of types of molds and mildews. A limited number of varieties are commonly associated with damage to buildings. Under conditions favorable to growth, these fungi can form dense colonies that may be visually unattractive. Of all the known varieties of mold and mildew, only a few are believed to pose health hazards. Among these few are "stachybotris chartarum" which can produce toxic mycotoxins. In the few varieties of mold and mildew that are believed to produce adverse health effects, concentrations must be relatively high to affect most healthy individuals. It is important to note that at the present time, there are no accepted federal, state, or local health-based standards for permissible exposure to mold and mildew. Nevertheless, whether it is believed that the potential for ill affects is little or large, it is universally accepted that houses should be kept as free from mold as possible.
Some common areas for mold and mildew growth in the typical residential environment are: 1) around window frames. Condensation or leaks often occur at window frames if the residence is tightly sealed and inadequately ventilated and if the temperature is colder outside than inside; 2) at and near toilets, sinks, and tubs (anywhere water splash and leaks are likely to occur); 3) in basements and other spaces which are below ground level, when drainage and/or waterproofing of walls is not adequate, or is failing due to age or lack of maintenance; 4) anywhere two or more pieces of wood are tightly fitted together, and water can get between them (typical examples are unflashed wood trim around windows and doors, wood railings and caps with open miter joints, and failure to maintain caulking in these areas); and 5) in poorly ventilated and damp enclosures.
Sometimes mold will grow in enclosed (not visible) locations, such as the cavities at exterior walls. If the building construction or lack of maintenance allows water to leak into wall cavities, mold can grow in the affected areas. Resulting damage can progress unseen for some time. Aside from gray or black stains and blotchy patches that are readily identifiable as mold, signs that should help identify some potential problems include softness in drywall, water stains at walls and ceilings, damp carpets, buckling or swelling of exterior surfaces, and a persistent musty odor. These are possible indications and do not prove that mold or mildew exist. The actual existence of mold and mildew must be established by visual observation and, in some cases, by appropriate testing and expert inspection.
Recommended Use and Maintenance:
You should seek help if you are concerned about possible indications of mold and mildew. Some sources for help include biology departments of major universities, city and county health departments, and the organizations to which health and hygiene specialists belong, such as the American Conference of Governmental Industrial Hygienists (ACGIH). This group can be contacted through their website:http://www.acgih.org.
For more detailed information, try these web sites:
IF MOLD AND MILDEW IS SUSPECTED TO EXIST, THE MOST IMPORTANT THING TO DO IS TO STOP THE SOURCE OF WATER, IF POSSIBLE, AND TO NOTIFY THE BUILDER IMMEDIATELY.
Comments: Prevention and elimination of leaks is discussed in other sections of this Manual (See Chapters on Walls, Roofs, Exterior Components and Utility Systems). Nevertheless, where leaks do occur, it is possible that mold and mildew may follow. If mold and mildew are present as a result of leaks, the repair of leaks should include removal of materials that are stained, coated or otherwise adversely affected by such organisms. Because removal of moisture can arrest the growth of these organisms and because surfaces that are not significantly damaged can be cleaned or treated, it may be possible to retain some or all affected building components during the repair process. In severe cases, removal or retention of building components is a technical matter that is best handled by a specialist in mold and mildew. The specialist will determine the molds and mildews present and the best way to remove them.
Most of the molds and mildews that appear around window frames and doors, in tile grout at tubs, showers and kitchens, as well as other interior locations, are the result of inadequate maintenance or improper use. At times interior humidity may rise sufficiently so that moisture condenses on cool surfaces (such as windows, doors, and walls). These conditions provide a fertile environment for the growth of molds and mildews, which most frequently appear around window and door frames, and at joints between frames and surrounding drywall and wood trim. Because of their warm and moist conditions, shower stalls and tub surrounds are also ideal places for mold and mildew to grow. Most of these conditions are controllable through appropriate use and maintenance of the house.
The appearance of mildew or fungi on outdoor siding may result from three principal sources: 1) leaks that allow water to enter between the siding and the material behind the siding; 2) an environment that is excessively damp, shady and lacking in air circulation; and 3) condensation of moist air on interior surfaces.
Mildew or mold should not be allowed to remain in the heating and ventilating systems. The problem usually results from moisture getting into the ductwork, either from a leak or condensation. Improperly insulated ductwork can also be a cause. It may be difficult to identify the presence of mold or mildew in ductwork, although a musty odor can be an indicator.
Recommended Use and Maintenance:
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