Toxic Intruder: Black Mold Panic Has Families Fleeing Their Homes

ABCNEWS.com ^ | 11/29/02

[finnman69]

TYVEK=good

lack of insulation and ventilation is bad.

[finnman69]

Air tight is not a good thing. Peopes and activity generate moisture which must be ventilated back out.

[Restorer]

Its not the insulation, insulation prevents moisture buildup

Beg to differ.

Insulation by itself is not a mold preventative and has absolutely nothing to do with whether moisture builds up or not. Improperly installed, it can make the problem much worse.

A wall, even an entire structure, is an integrated system. Each part affects every other part. If these affects are not thought through in detail, the results can be disastrous.

Traditional materials like wood, brick, stone and plaster had major margins of error if miscalculations were made. Modern methods do not allow for such.

I highly recommend Moisture Control Handbook by Joe Lstiburek. It's available from Amazon for less than $20.

If you really learn this niche as an architect, I can guarantee you that you will not lack for lucrative work in the next 20 years.

But it is not nearly as simple an issue as you seem to believe presently.

[finnman69]

Much of the problem is that building techniques have changed considerably from years ago. For one, lumber yards kept their stock indoors. Now they are stored outdoors. Houses are now built (framed and enclosed) within a week, locking moisture inside. Making a home airtight (Tyvek) and superinsulation donesn't allow outside air to circulate. All this in the name of enegy efficiency.

BINGO! This is a HUGE problem of fast track construction, where interior finishes are being placed without the building envelope being sealed. I just saw photos of a convention center in Orlando where they has to rip evenything out becasue the partially finished interiors became infested with mold.

[meyer]

I don't disagree. Frankly, I think executives of large corporations should be held criminally responsible for the misdeeds of their employees in the interests of the corporation.

To the extent that those actions are illegal and the employee is coerced or directed by his leaders, the corporation, or at least the manager making the command, is responsible in the eyes of the court. That is as it should be.

We all know that almost never happens now, so the primary effect of getting rid of punitive damages would be to remove all disincentive for corporations to misbehave. The end result of that would probably be more regulation, micro-management by government oversight.

Actually, it does. If it is illegal, it can be prosecuted. Corporations notwithstanding, if someone does something illegal, they stand to be prosecuted if caught. And generally, despite media coverage to the contrary, they do get caught. I don't see the need for additional government oversight - there's too much now in most cases.

Punitive damages, with all their drawbacks, are certainly preferable to that, IMHO.

I have to disagree. Punative damages have gotten way out of hand. And they are almost always based on junk science or misinformation. That is why folks are skeptical on this thread. Lawyers shop for good courts and enjoy the laws of averages. For every jurisdiction that throws out or defeats a case, there is another that may give a win. They will gladly take 100 losses if there is 1 win because it provides financial input for the profession as a whole. Most lawyers, like most people, like money. They just don't want to produce anything to get it.

I've had a case where the amount needed to repair fire damage properly was $20k. The adjuster was going to offer them $10k. He looked me in the eye and said, "They're old, black and poor. What are they going to do about it?" The answer was they accepted the 10 grand.

The question is, did the insurance adjuster underestimate or did you overestimate. I'm not saying you're wrong, but there's two parties to this and I've only heard one.

If a corporation has strong financial incentives to behave badly, it needs at least some financial counter-incentive to avoid such behavior. Punitive damages, for all their faults, provide that counter-incentive. (Well, sometimes they do.) :)

I agree to a point. But, fraud and other laws dictate criminal behavior, corporate or otherwise. And corporate officers aren't always privy to acts of an individual trying to climb the ladder. And, shareholders aren't any more knowledgable than officers and are generally less so.

I just won't buy the corporate image as portrayed by the media that shows all corporate officers to be thiefs or worse. That image just doesn't portray the vast majority of corporate leaders.

[meyer]

Probably wasted $50 billion, not counting side-effects on business.

The side effect on business for overzealous asbestos removal far exceeded $50 billion over the last 20 years.

[Restorer]

I just won't buy the corporate image as portrayed by the media that shows all corporate officers to be thiefs or worse.

I agree. However, how many officers spend as much energy ensuring their subordinates did the right thing as they do that they did the profitable thing? Not very many.

I strongly suspect there is a lot of plausible deniability going on.

Corporations have strong financial incentives to cheat. They only have the moral character of their officers and employees, plus the fear of getting caught, to prevent them from doing so. I think it's pretty obvious which is the stronger incentive. Especially in today's world, where morality has been mocked for 35 years.

[finnman69]

Here's more info on mold and what causes it.

Preventing Mold
The key to mold control is moisture control. Solve moisture problems before they become mold problems! Some tips to help you get a jump on preventing mold include:
• Fix leaky plumbing and leaks in the building envelope as soon as possible.
• Watch for condensation and wet spots. Fix source(s) of moisture problem(s) as soon as possible.
• Prevent moisture due to condensation by increasing surface temperature or reducing the moisture level in air (humidity). To increase surface temperature, insulate or increase ventilation (if outside air is cold and dry), or dehumidify (if outdoor air is warm and humid).
• Keep heating, ventilation, and air conditioning (HVAC) drip pans clean, flowing properly and unobstructed.
• Vent moisture-generating appliances, such as dryers, to the outside where possible.
• Maintain low indoor humidity, below 60% relative humidity (RH), ideally 30-50%, if possible.
• Perform regular building / HVAC inspections and maintenance as scheduled.
• Clean and dry wet or damp spots within 48 hours.
• Don't let foundations stay wet. Provide drainage and slope the ground away from the foundation.
Source: Indoor Air Quality (IAQ) Resources by Building Air Quality, a Texas-based consulting firm.

Mold Growth In Heating Season
In a heated climate, mold grows on interior surfaces. Typically, the interior surfaces of exterior walls are cool (due to heat loss), while moisture levels within the conditioned space are high. Mold growth can be controlled in two ways: (1) by preventing the interior surfaces of exterior walls and other building assemblies from becoming too cold and (2) by limiting interior moisture levels. Adding insulation to a wall or ceiling raises the temperature of the inner surface. Controlled ventilation and control of moisture sources limit interior levels. Home Energy Magazine online, November/December 1995

Mold Growth In Cooling Climate
If exterior humid air comes in contact with the cavity side of cooled interior gypsum board, its relative humidity can rise above 70% and mold growth can occur in the cavity. Impermeable wall coverings such as vinyl wallpaper can make the problem worse by trapping moisture between the interior finish and the gypsum board.
Home Energy Magazine online, November/December 1995

Ten Things You Should Know About Mold
• Potential health effects and symptoms associated with mold exposure include allergic reactions and other respiratory complaints.
• There is no practical way to eliminate all mold and mold spores in the indoor environment. The way to control indoor mold growth is to control moisture.
• If mold is a problem in your home or school, you must clean up the mold and eliminate sources of moisture.
• Fix the source of the water problem or leak to prevent mold growth.
• Reduce indoor humidity to 30-60%. Decrease mold growth by venting bathrooms, dryers, and other moisture-generating sources to the outside; using air conditioners and de-humidifiers; increasing ventilation; and using exhaust fans whenever cooking, dishwashing and cleaning.
• Clean and dry any damp or wet building materials and furnishings within 24-48 hours to prevent mold growth.
• Clean mold off hard surfaces with water and detergent, and dry completely. Absorbent materials such as ceiling tiles that are moldy may need to be replaced.
• Prevent condensation. Reduce the potential for condensation on cold surfaces (i.e., windows, piping, exterior walls, roof or floors) by adding insulation.
• In areas where there is a perpetual moisture problem, do not install carpeting (i.e., near drinking fountains, classroom sinks or on concrete floors with leaks or frequent condensation).
• Molds can be found almost anywhere; it can grow on virtually any substance providing moisture is present. There are molds that can grow on wood, paper, carpet and foods.
Source: National Multi-Housing Council

Moisture Control In Bathrooms
A good exhaust fan is critical to moisture control in bathrooms in both hot and cold climates. Choose one that is quiet and can exhaust at least 70 CFM. To ensure that any fan is capable of moving air against the friction of the duct run and the pressures caused by typical duct leakage, choose a fan rated at 0.2 inches of water column (WC), rather than the more common 0.1-inch WC rating. Putting the controls on a timer will help. Homeowners should be instructed to leave the fan on for at least 15 to 20 minutes after showering.
Source: Home Energy Magazine 8/02

The Building Envelope

A good building envelope is the starting point for a good house. The most recent builder guides and research projects suggest that the most efficient, most economical walls will have the following components: exterior finish, drain plane behind the cladding material, wind protection layer, full coverage insulation, an appropriate structural wall system, air barrier, vapor retarder, interior wall material, and finish. In cold climates, the air barrier and vapor retarder should be placed on the interior, or warm, side of the insulation before the interior wall material is installed. In hot climates, particularly those that are humid, it is critical to have a vapor retarder and air barrier on the exterior side of the insulation. In general, the wall system must keep water and moisture out, must resist heat flow in either direction and must retard air and vapor flow from the moist side.
Source: Home Energy Magazine 8/02

Prevention Is The Cure
Here are some of the most common problems and their solutions:
• Roof Flashing. Every roof detail - hips, valleys, ridges, rakes or eaves - is a potential leak. Leaks at penetrations such as vents and chimneys are most common. Make sure roofing felt is always extended well over the top of the base flashing. Mastic will never last as long as the rest of the roof and often fails soon after installation. Install drip edge along rakes and eaves and overlap it with roofing felt. If you just cut the felt at the sheathing edge, wind-driven rain will find its way under the roofing.
• Wide Overhangs. "The days of the diminutive overhang are over," says Peter Pfeiffer, AIA and Austin-based architect who frequently consults with builders on residential indoor air quality and energy concerns. Particularly in the South, houses must have deep overhangs to shield walls from rain, which can soak the siding and be driven inward by outdoor warmth.
• Insulation. To prevent extreme temperatures from creating cold spots (or hot spots in some climates) inside the wall, pay close attention to insulation details, particularly at problem areas - exterior corners, the juncture between roof and wall framing and rim joists - where framing often makes access difficult when applying insulation. Framing techniques such as "California corners," raised trusses and let-in foam at rim joists can usually solve these problems.
• Insulate cold water pipes and seal HVAC ducts. In hot, humid climates, it is often necessary to insulate cold water pipes to prevent surface condensation. This has become particularly important in the past 15 to 20 years, notes Pfeiffer, as homeowners now tend to cool houses much more than they used to. Leaky HVAC ducts can overcool spots in wall cavities, attics and crawlspaces where moisture will condense. Ducts should be sealed with mastic, not just duct tape.
• Window and door flashing. In addition to cap flashing above the head trim of windows and doors, flashing should be installed beneath the trim and housewrap. "This is rarely done," says Pfeiffer. Typically a continued on next page house is wrapped, window and door openings are X-cut, window and door units are installed, and the cap flashing is applied directly over the housewrap. This method, while efficient, invites water into the wall cavity. Windows with flanges should be set over flashing "splines" installed first at the sill, then along the sides, and last across the head. Most important, the housewrap must overlap window flange and flashing.
• Drainage plane for stucco and brick. Every exterior wall should have a continuous drainage plane between siding and sheathing. This is especially important with porous materials such as stucco and brick, which absorb water and draw it inside. A drainage plane can be as simple as building paper or felt properly installed over the exterior sheathing and (in the case of stucco) under the metal lath. Avoid synthetic stucco systems that manufacturers claim do not need a drainage plane.
• Rain screen for wood siding. Wood siding should always be back-primed with a water-repellent preservative (best choice) or an oil-based primer. Just as important, wood siding should always be installed over an airspace using vertical strapping or wedges between siding courses. This is critical over foam sheathing. But even over plywood sheathing and housewrap, the airspace provides the only way to dry the back side of the siding, which will inevitably get wet.
• Foundation drainage. Water will always take the path of least resistance, so a foundation barrier combined with gravel backfill and perimeter drainage will further protect against groundwater infiltration. To keep water outside the foundation, the top of the interior slab should always be above the top of the drain tile. In areas with high seasonal water tables, use both exterior and interior perimeter drains or a stay-in-place footing form.
Source: Builderonline.com

[Restorer]

The question is, did the insurance adjuster underestimate or did you overestimate. I'm not saying you're wrong, but there's two parties to this and I've only heard one.

Perhaps I was unclear. The adjuster admitted to me that it would cost $20,000 to repair the property correctly. He just didn't care, and believed he could get away with it. He was right.

Of course, I can't prove any of this, but it has stuck in my craw for 15 years.

And that's only the most egregious of literally thousands of similar situations I've dealt with over 30+ years.

[Restorer]

All excellent advice. One comment.

Putting the controls on a timer will help. Homeowners should be instructed to leave the fan on for at least 15 to 20 minutes after showering.

Fans are available that are controlled by a humidistat, which will continue to run till the humidity in the area drops below the preset point. A much better idea.

[Restorer]

All excellent advice. One comment.

Putting the controls on a timer will help. Homeowners should be instructed to leave the fan on for at least 15 to 20 minutes after showering.

Fans are available that are controlled by a humidistat, which will continue to run till the humidity in the area drops below the preset point. A much better idea.

[Restorer]

Sorry. My thumb slipped.

[meyer]

Corporations have strong financial incentives to cheat.

Lawyers and plaintiffs also have strong financial incentives to cheat. And, there's far more lawyers and pliantiffs than there are corporate officers.

Plus, corporate officers are more likely to be Republican which is a good indicator that they are honest. So there. :^)

[finnman69]

To suim it up. Mold forms something like 80% of the biomass on this planet. God designed mold to do one thing, eat dead wood. So what do us dumb humans so, build homes out of wood and paper faced gypsum biard.

[Eva]

I was told by a local builder that the plastic wrap that is being used on the outside of houses (I think its called TYVEC or something like that) is part of the problem. It seals the house too well, so it can't breathe.

[Restorer]

there's far more lawyers and pliantiffs than there are corporate officers.

Not entirely sure that's true, if you figure in all corporations, of all sizes.

But your point is well taken.

[finnman69]

If so, is the paper content in the sheetrock the reason?

Mold is designed to eat dead wood, what is paper made of?

There are new glass mat faced drywall products that are very mold resistant, its more expsensive than normal drywall, but its cheaper than a majpr mold problem.

[Restorer]

Tyvek house-wrap can contribute to the problem, especially in certain climates (those in which the wall cavity would normally dry to the outside).

But at least certain types of Tyvek are much more permeable to water vapor than most people realize. Unfinished drywall has a permeance of 50, still air has a permeance of 120, 6-mil poly has a permeance of .01. At least one variety of Tyvek has a permeance of 80.

I suspect in most cases Tyvek is a scapegoat, an easily understandable place to pin the blame. Most houses that have Tyvek and mold would probably have grown mold if the Tyvek had been left off.

[Eva]

Many of the builders around here are going back to old fashioned tar paper.

[Restorer]

Good idea. It has some interesting characteristics that make it a better choice in many climates.