Construction Defects - Toxic Mold
March 1, 2009
Molds, mildews, mushrooms and yeast are types of fungi. Humans have been living with fungi and mold ever since the dawn of mankind. Yet it has only been since the mid 1970’s that we’ve come to recognize the seriousness of toxic mold growth in buildings. Some experts believe two factors have contributed most to the recent increase in residential mold problems.
Trend Toward Energy Efficient Homes. After the oil crisis of the 1970’s, homes started becoming much more energy efficient. Saving heating and cooling costs means making homes less drafty and more airtight. As a consequence, reduced ventilation allows moisture to persist where it can create ideal conditions for mold growth.
Progress in Medical Science. Physical symptoms of toxic mold exposure are often similar to cold or flu symptoms, and little attention was paid to the cause. In more serious cases, mysterious neurological symptoms baffled family practitioners and specialists alike because the effects of toxic mold were not widely recognized. Today, there is much greater knowledge and awareness of toxic mold and its symptoms.
Types of Mold
Scientists don’t agree precisely on how many types of mold there are, but most estimates are in excess of 100,000.
Some are the type you find growing on moldy bread, or the leftover food you forgot was in the refrigerator. Some are the type you hate to discover growing in your shower or bathtub. These types and many others are not particularly harmful. (Think “blue cheese.”)
On the other hand, some molds that are found in homes can cause people to experience allergic reactions. These can be especially problematic for people who have asthma or other respiratory problems. Among this group some names you may hear are cladosporium, penicillium, and alternaria.
Other types of mold, however, are referred to as toxic molds. These include particular species of stachybotrys, aspergillus, and pencillium among others. Some members of the stachybotrys family are referred to as “black mold” or “killer mold.”
Where Mold Comes From
Molds produce spores, which are like microscopic seeds they emit into the air. The air around us contains thousands and thousands of these tiny spores that float on the faintest air currents and eventually land on virtually every accessible surface indoors and outdoors. To begin growing, the spores require two things – water and food.
Mold’s purpose in nature is to break down organic material and recycle it into the environment. Therefore, its food can be any organic material. In your home, wood, paper and some types of cloth, caulk or glue can be food sources for mold. The most significant mold nutrients in the home are:
- Wood framing inside wall, floor, and roof systems
- Paper coverings on sheetrock and insulation
Water can be provided either by the moisture content in the food source, by very high humidity, or by an actual water source. Examples are wet lumber or drywall, steam from cooking or bathroom showers, or a leaky roof or window, or a plumbing leak.
With food and water, a spore starts growing into mold that produces more spores. As long as the food and water hold out, the mold continues to grow and multiply, soon forming a very visible and identifiable colony.
How Mold is Harmful
Mold emits into the air both spores and gaseous byproducts of its digestion. These contribute to mold’s signature “musty smell.” Different people have different reactions to these indoor pollutants. Some may have little or no physical reaction. Others may experience stuffy nose, headache, dizziness, or nausea. People already suffering from a respiratory condition may find their condition worsens in the presence of mold.
In some cases, the byproducts of digestion can be toxic if the mold’s food source contains toxic elements. For example, mold growing on wallpaper containing arsenic-based pigments can emit dangerous arsine gas.
Many molds also produce toxic substances that help them compete for survival in the natural environment. Some of these mycotoxins (which are present in both the mold and its spores) are especially harmful to humans. Depending on the mycotoxin’s toxicity and the strength of the individual’s immune system, a person’s reaction to a particular mycotoxin could range from minor illness to death.
Causes of Mold Problems
Mold is almost always the result of wetness in a location that should not be wet. This can happen if there is:
- A structural leak allowing water intrusion
- A plumbing leak
- Buildup of humidity in a kitchen, laundry or bath area
- An accident involving a lot of water.
null
If any organic food source remains wet for more than 48 hours, the spores already present or those happening by are going to begin forming a colony.
Construction Defects That Cause Mold
The most common type of construction defect leading to a mold problem involves some sort of hidden water leak. Being hidden contributes to mold problems in two ways.
- When a leak is hidden, it is not discovered and therefore not corrected, allowing wet conditions to persist and a serious mold issue to develop.
- A hidden location is often poorly ventilated, and even a minor leak can become a major mold problem because the water does not evaporate.
The source of a leak caused by a construction mistake or design error could be:
- A leaky roof
- Water entering a wall or floor space that was not adequately or correctly waterproofed
- Faulty or inadequate ventilation
- Improper or faulty drainage
- Leak in plumbing or drain systems
- Improper installation or faulty construction or waterproofing around sink, tub, toilet or shower
Inspecting for Mold
Now that you know how toxic mold can be, you may be frightened of touching anything in your home that even remotely resembles mold. According to building inspection consultant Daniel Friedman, however, you need to bring in a professional only if:
- You have reason to suspect illnesses at home are being caused by mold.
- You suspect (or know) the home has leaks or there was an accident involving a lot of water inside the house, especially if people in the home are highly susceptible to mold because of allergies, age (elderly, babies), or respiratory or immune system problems.
- You can see visible mold, and it covers more than 30 square feet (approximately 5 ft. x 6 ft. or 3 ft x 10 ft.)
If there isn’t mold already visible, a mold inspector will typically set up special equipment for capturing air samples outside your home, and from many locations inside your home. The samples are then sent to a laboratory where the mold spores in each sample are counted and cultured for identification. When the spore counts and types inside the house are roughly equal to those outside, the home is assumed to have no mold problem.
If the spore count is significantly higher in one or more inside locations, the inspector then begins the process of trying to pinpoint the source of the mold spores. If any of the mold samples revealed toxic mold spores, then the inspection and cleanup may involve people working in hazmat suits inside temporary, plastic-enclosed clean rooms with HEPA air filtration systems.
Engaging an Attorney
If you discover your home has a mold problem and the cause appears to be from a construction defect, you should talk to an attorney before beginning any mold cleanup. Occasionally a construction defect case involving mold is lost because of inadequacies in mold testing, inspection or repair/remediation procedures. Your attorney should be sure that all available evidence is properly collected and preserved before it is compromised by the mold cleanup and repairs.
If you need assistance finding an attorney, please contact us using the form on the right.
Related Articles
- Construction Defects - Foundation Cracks
- Construction Defects - Cracked Stucco
- Construction Defects - Electrical Problems
Got something to say?