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Mold 

Most corrosion problems, if they result in a leak or piping failure, are quickly addressed in the form of repair or replacement.  Significant property damage can result from the failure of even a 1 in. diameter line under moderate pressure, although in most cases the failure is quickly addressed.

Where the pipe leak is a one time occurrence, any remaining moisture hidden behind the walls or within ceiling and floor areas is soon evaporated and dissipated, and the area returned to its normally dry state.  This is especially true in air conditioned office building environments, or in areas where low humidity levels are normally maintained.

Ironically, an entirely different threat to building operations is created for the opposite corrosion scenario where the smallest water leaks occur.  Such conditions commonly exist for the more mild corrosion conditions, or for early stage corrosion problems that do not produce significant enough water volume to warrant immediate attention.  In the photographs below, slow leakage through the thread may have existed for years, yet remained concealed above ceilings or behind access doors, having never created a visible presence.

Slow Leaking Threat

Here, it is the small amount of water produced over an extended period of time that allows various forms of mold, many toxic in nature, to develop and thrive.  Once established, molds can have a severely negative impact on human health depending upon the nature of the species involved, its metabolic by-products, spores generated, its physical location, concentration, the volume and duration of an individual’s exposure to the mold or by-products, and the physiological susceptibility of those exposed.

Severe consequences can result from a mold condition – ranging from downtime and a costly remediation of the affected area – to health damage and civil and criminal lawsuits.  Some other facts and consequences of a mold infection include:

Mold infections can develop in the ears, nose, eyes, mouth, sinus, skin, lungs, and brain.

The metabolic by-products of molds are volatile organic compounds, spores, and mycotoxins – all very harmful to human health.

Common health effects include various allergic reactions, fatigue, shortness of breath, dizziness, rashes, headache, memory loss, problems concentrating, chronic fatigue, nose and throat irritation, runny nose, watery eyes, sneezing, coughing, and breathing problems.

In extreme cases, mold can cause neurological problems, brain damage, internal hemorrhaging, and even death.

Molds in office building locations are the often unrecognized agents responsible for a significant number of tenant and employee illnesses, and lost productivity.

High legal costs can result.  $40 million was awarded in one Florida case when it was discovered that Aspergillus mold developed in a county courthouse due to construction defects.

$14 million was awarded in another court case when it was determined that construction defects resulted in mold contamination within a building.

Lawsuits related to toxic mold claims continue to increase at an alarming rate.  During the last three years in the United States and Canada alone, more than 10,000 mold based lawsuits have been filed.

Whether justified or not, large court verdicts related to asbestos and tobacco injuries, have emboldened plaintiffs to pursue large, sophisticated personal injury litigations in mold cases.

In all cases, the right combination of water, moisture, low light, and warm temperatures are the prerequisites for mold to develop.  A replenished source of moisture is the most important factor, with the vast majority of molds requiring relative humidity of at least 70% for growth.  Most serious large scale mold outbreaks inside buildings occur where porous materials have been kept wet by a constant source of water – such as through a sustained leak or a sweating cold pipe surface.  The high volume of air normally moved within any office building only helps to spread the problem.

A corrosion threat often reveals itself through pinhole leaks at its most vulnerable points first – such as at threaded locations, valves, and other joints.  In office building environments, a pinhole leak is a common occurrence months and possibly years prior to a full blown piping failure.  In such cases the leak may continue unaddressed simply because it is hidden within a ceiling, floor, or behind a wall.

The amount of water produced by small leaks, while often saturating its own localized area, may not be enough in volume to extend into noticeable space to reveal itself.  In such cases, the rate of evaporation is often sufficient to contain a small leak from being noticed outside its immediate area, but in the process, increase the humidity level of the enclosed area to further encourage a potentially more serious mold outbreak.  In other cases, a small leak problem may may be considered only a minor nuisance by maintenance personnel, and thereby rate a lower priority for repair, or receive no attention at all.

While the volume of water produced from a slight drip will be far less than even the smallest pipe failure, it is the constant presence of water that will typically result in a mold condition.  Given favorable temperatures, mold can spread widely within an enclosed area – allowing its spores and metabolic by-products to migrate elsewhere throughout the building while the main body of the mold contamination remains hidden from view.

• Common Mold Problem Areas

Mold, if present in sufficient quantity, is most easily identified by its characteristic dark brown or shades of black discoloration of the surface.  Mold usually presents a raised and fuzzy or sooty appearance, but not in all examples, and should be suspect at any surface which is wet or damp.  Molds can grow on wood, paper, carpet, foods, and other building materials, but are rarely found on steel, concrete, glass, plastic and other smooth, nonporous surfaces.

Further identification and qualification of the problem requires professional sampling and laboratory identification, followed by effective remediation.  Periodic indoor air quality testing and good maintenance upkeep are the best preventative measures against mold outbreaks.  Some common examples of mold in office building building environments are shown below.

• Common Mold Examples

Leaking Pipe A constant pinhole leak from a domestic water pipe behind this wall did not create enough water to be noticed, but did moisten the sheetrock sufficiently to create this severe mold condition. No options exist to remediate this space except to remove the affected area, clean and disinfect remaining structures thoroughly, and replace with new material.	Wet Insulation This represents a common problem where thin or ineffective pipe insulation allows area moisture to condense at the cold pipe surface and produce a water condition. Constant moisture in the usually dark areas where pipe is installed provides the ideal environment for mold to become established.  Released spores travel and spread the mold into adjacent areas.

Leaking Condensate Pan A clogged or overflowing condensate pan from the above window unit produced constant moisture in the ceiling above this apartment. Where frequent painting covered the early signs of this problem, the severity of the mold condition eventually expanded to the point of requiring major remediation.	Hidden Threat With a mild discoloration of the outer sheetrock wall suggesting a mold problem, the affected area was removed to reveal a much greater contamination threat inside. In many examples, a tremendous volume of hidden mold contamination can exist where only little is observed from the outside.

Beginning of Mold Problem Cold sweating pipe insulation defines inadequate insulation to hold back the temperature.  Water then saturates the fiberglass to produce an even faster migration of temperature and therefore greater condensation. Totally saturated pipe insulation is a major starting point for mold contamination, and can only be addressed by removal and better insulation coverage.

Devastating Loss The widespread corrosion of steel condensate lines to the cooling system allowed water to trickle down the interior walls to the bottom floor of an 18 floor apartment building.  The problem was ignored and painted over for years. This allowed massive mold infection within all walls to the point where all 1st floor residents were evacuated. Most interior walls required full replacement.

Poor Insulation / Hidden Problem The combination of cold pipe temperatures, damaged insulation, and high area humidity produced a mold condition along most of this chill water line. A painted outer pipe covering had concealed its presence, thereby allowing the mold to spread throughout the area.	Expanding Problem Another example of the severity a mold condition can reach if unaddressed in its early stages. Here, and in another example, a clogged A/C condensate line forced water to run down the length of the entire riser to produce mold conditions throughout the building.  Major remediation was required.

Foam Insulation Foam insulation is often preferred due to the lack of irritation from fiberglass type products.  It is generally assumed to provide better protection although not true. It is also assumed to not develop mold contamination although the above photo also shows that as untrue. Soft foam insulation easily allows moisture condensation at a cold pipe surface, and is a common contributor to mold conditions.

Wet Foam Insulation Another example showing wet and saturated foam insulation with the pipe surface covered in black mold. While allowing moisture to enter the insulation, foam also holds the moisture and allows it to migrate along horizontal runs. Unless covered at the outside with a hard and moisture sealed covering, all insulation can produce similar results.

Hidden Leak Another example showing the result of a small pinhole drip which remained unseen and hidden for many years. Mold originating in this one area migrated through the wall partitions to other areas and established additional mold colonies in areas otherwise unlikely. Today’s public concern over the mold contamination and the threat of litigation defines large scale material replacement in almost all examples.

Mold Contamination Here we show another example where thin or ineffective pipe insulation allows area moisture to condense at the cold pipe surface and produce a mold condition. Constant moisture in this dark area has allowed mold spores to grow and spread to all piping. Without remediation spores will spread the mold into adjacent areas of the building.

• Lower Wall Thickness

The water for a mold condition can originate from a variety of different sources.  Problems such as a thread or valve leak, or drain line crack are corrected relatively easily, where as a leak throughout a condensate return riser or water saturated insulation at a cold water line can require major repair and remediation efforts.  Below are some of the most common problem areas often found to produce mold conditions:

Pipe Leaks

Thread leaks are a common problem wherever corrosion rates exceed 5 MPY, or where direct steel to brass or copper connections exist to produce an accelerated galvanic loss.  In many cases such leaks are hidden from view and will only be noticed once the rate of water loss exceeds evaporation and is sufficient to become a problem.

Obvious tell tail signs are wet ceiling tiles, or tiles having brown or yellow discoloration.  A crystalline white appearance of the tile surface is often seen due to the evaporation leaving behind the minerals contained in the water leak.

Again, the smaller the leak, the less likely it is of being noticed, but the greater threat of it becoming a mold hazard to the building property.

Condensate Pans

Condensate pans are necessary in order to collect and remove the moisture condensed at the cold temperature coils used in air conditioning systems.  Ideally, they are designed and installed so that the water collected is quickly removed from the area and not allowed to collect.

The most common problem from condensate pans is the capture of sufficient airborne particulates to clog the exit from the pan.  The growth of bacteria and other microbiological agents in the condensate pan often travels into the condensate line itself to produce major obstructions of water flow.

While the regular application of biocide tablets to condensate pans does help minimize the microbiological growths, most condensate systems will experience frequent clogging problems.

Over time, most metal condensate pans will rust and leak, condensate return lines will fail, and the risers themselves corrode to produce a very common source of water for molds to thrive.

Wet Pipe Insulation

The insulation at a cold water pipe will usually slow the transfer of heat or cooling, but may not necessarily be effective at preventing area moisture from reaching the cold pipe surface.

Taking many years to develop, moisture will migrate through the typically installed fiberglass insulation to condense at the cold pipe surface.  This in turn will eventually saturate the pipe insulation – providing the perfect environment for molds to develop.

Thicker insulation is the solution, coupled with a heavy exterior coating of the insulation to serve as a moisture barrier.  Where cold pipe is traveled through an area of high humidity, such as exists in mechanical room areas, such precautions become even more important.

High Humidity

High humidity alone may not be sufficient to create a mold condition, but it does greatly encourage it.  Excessive humidity conditions are often created due to steam leaks, which in turn can produce moisture condensation at even moderate room temperature surfaces.

Combined with warm temperatures, such conditions will often lead to a mold problem unless the fundamental cause is addressed.

Originating from often a minor cause, a mold condition can produce a major loss to any building property in the form of lost productivity and income, lost rental space, property damage, personal illness, lawsuits, and high legal expenses.  Such consequences can be avoided generally through good engineering, some preventative and predictive maintenance, a prompt attention to any discovered operating problems, and effective corrosion control.

• Additional Examples

CorrView International, LLC offers a series of Photo Galleries taken from years of past ultrasonic piping investigations, which address the above as well as additional corrosion conditions.

A review of the different types of corrosion is often helpful in initially determining the likely corrosion cause.

In many cases, however, a combination of conditions will exist within the same piping system.  View our extended Photo Galleries of different corrosion types and failure conditions.

Problems related to mold contamination are represented.

© Copyright 2023 – William P. Duncan, CorrView International, LLC