Monitor These 9 Vital Signs to Avoid Widespread Mold & Moisture Problems in Your Building
By Richard Scott-AIA, NCARB, LEED AP of Liberty Building Forensics Group
Unique vital signs can help determine the health of a building as it relates to a mold and moisture problem, similar to measuring the health of a human body by taking vitals. This analogy is applicable to many different building types and construction phases. This kind of analysis can help locate the hidden risks of a mold and moisture problem and can also be beneficial when planning a renovation by bringing awareness to potential moisture-related problems, allowing owners to course-correct, budget, and plan accordingly.
In our decades of building forensics experience at Liberty Building Forensics Group (LBFG), we have seen repeated occurrences of moisture and mold damage in buildings that had previously displayed warning signs. If these vital signs had been addressed early on, catastrophic problems could have been avoided.
Instead, many building owners and operators rely solely on a property condition assessment (PCA) to determine if they have a problem. This prescribed methodology is intended to provide a level playing field for what every PCA will provide, and also to limit the exposure and liability risk for those performing it. However, our firm has found that these PCAs, which follow American Society for Testing and Materials (ASTM) requirements, are not set up to locate hidden issues and in fact often overlook potential problems.
The 9 Vital Signs
A building’s “vital signs” can be used to assess whether there is existing mold or moisture damage in your building, or to help prevent a future outbreak. Using the analogy of a human’s symptoms, you can monitor a building’s bad breath, breathing, fevers, rashes, fractures, water retention, bleeding, and heartbeat to determine its health from a mold and moisture perspective. The building envelope can be compared to the skin; the structure to the bones; and the mechanical systems to the lungs, heart, and circuitry system.
When assessing whether there’s mold damage, the first thing to look for is bad breath (i.e., musty and mold-type odors). If you can smell mold, you typically will have mold. The inside of a building may have been kept up very well - for example, a hotel may have tried to maintain a positive guest experience. The rooms may be clean and there may be no evidence of mold in the building, yet a horrible mold smell may still permeate the air. The maintenance and housekeeping staff may have tried to remove any visible mold growth, but that doesn't mean it doesn't exist elsewhere. Often this mold will be hidden inside wall cavities or even on the backside of case goods.
The second vital sign to look for - and perhaps the most important one, in our experience - is breathing (i.e., building pressurization). Pressurization is one of the biggest drivers in a building mold and moisture problem. Hotels are notorious for having pressurization problems because of
the way they're frequently designed and operated. They often have a continuous toilet exhaust which, in a hot and humid climate, creates a negative pressure situation that pulls hot, humid air into the building. In a cold climate, the opposite can be a problem; positive pressurization drives interior air that's more humid than the outside out through the wall cavity, where it can condense and cause mold in the exterior walls. Either way, pressurization and direction are critical aspects of determining the potential mold health of your building.
The third thing to look for is fever sweats (i.e., elevated relative humidity, or RH). If measured accurately, elevated RH is going to be a good indicator that there’s a problem. Be sure to look at the mechanical system to make sure it can deal with any humidity load it might experience in a particular climate. Keep in mind that elevated RH in a building may be a result of hidden water retention inside the wall cavities from a rainwater leak. Our building experts have seen instances in which moisture wetted interior walls, which then emitted the water over time, increasing the RH. So be sure to first check RH, but then also check for any water retention.
Rashes and Bruises
Number four, be sure to look for rashes and bruises (i.e., discoloration), which can often indicate moisture and mold damage. While pink spots or staining on a vinyl wall covering are not mold themselves, this vinyl discoloration is a result of bacterial action that indicates moisture is occurring at that spot. Another telltale sign to look for is any damage on your tackless strips, which are often a visible indicator of whether you've had previous water intrusion. Pull up the carpet and if there is any staining or damage of the carpet tackless strip, use this evidence to trace where the water might be coming in.
Exterior wall surfaces also certainly need to be looked at, since they can show whether the building has a mold or moisture problem. Excessive cracking could be the result of water damage or of water getting trapped behind a stucco system. Depending on the building orientation, excessive algae and mildew growing on the side of the building can also point to a problem. Efflorescence coming out of the cracks of brick, stucco, or any kind of masonry can be an indication that trapped water behind your system is not able to adequately weep out.
It's important to review your construction drawings and maintenance logs of the exterior, and also do a detailed visual building survey with some destructive testing. Also, be sure to inspect behind water leaders, as hidden cracks can allow water to get into the building.
Another sign to look at is your last check-up (i.e., brand standards). How were brand standards applied during the last renovation, and did they or have they cause(d) any problems? Do you need to consider revising the brand standards for your local climate? Brand standards are developed on a global basis and are often applied without regard to specific climates, which may violate good practices and can result in moisture and mold problems.
Often a design team, owner, or operator will leave brand standard application up to the construction team, figuring they will make any necessary adjustments to brand standards based on the climate because that's part of their job. However, this step is often skipped because of financial incentives to apply the brand standards. The design team may also be reticent to go against a particular look or requirement.
Another element to look for in a building is fractures (i.e., structural weaknesses). Just like you'd look for bone fractures, look for any “fractures” in the structural system of the building. Uneven, sagging, or springy floors are usually an indicator of water intrusion, especially if it's a wood frame building. (Wood frame construction is prevalent in the industry right now, being used for both apartment complexes and hotels up to five stories.)
Lightweight gypsum concrete flooring can become weak and brittle due to water damage. Water can cause the lightweight to crack as it absorbs moisture and then dries out. In some cases it can even affect the floors below, causing the wood to rot away and leaving a weakness in the system. It's always good to pull back the carpet and look for fractures in your lightweight, as well as problems in the wood structure and sheathing.
Cracks and bulges on the exterior of stucco buildings can be an indicator of a problem. A building may look good on the outside, having been painted over time and repaired by maintenance whenever a crack appeared. We’ve found through experience, however, that when the building is pulled apart, the wood structure is found to be severely damaged. When doing a visual inspection of the outside of a building, look for small indicators that will show that you've got a problem inside the walls. Destructive testing may need to occur in areas of suspected potential problems. Edges of balconies and around windows are usually the first areas that fail due to water intrusion, so they are an excellent place to start looking.
Water retention can occur through many different sources. It can be difficult to determine the source of a humid room. The HVAC system might be operating but there could be water retention in the walls. While infrared (IR) thermography can be used to help locate the moisture, it has to be taken with a grain of salt: IR imagery can often lead to false positives or negatives and needs to be verified with a moisture meter. We’ve seen cases where IR imagery pointed to an area
that had some water damage but when tested with a moisture meter, it was dry. Additionally, the IR imagery showed an adjacent area to be dry, but when tested with a moisture meter, it was in fact wet and had been missed by the IR camera. So it's critical to understand the limitations of the equipment.
If you have water coming in (i.e., bleeding), you've obviously got a problem. Look for gaps around sliding glass doors, windows, and any other wall penetrations. Sometimes they're not obvious, so make sure to pull back the carpet and inspect thoroughly, as the carpet can hide potential gaps. Issues with detailing, sealants, and poor craftsmanship are often the cause of water intrusion. It’s critical to make sure windows can marry to difficult products.
Water intrusion isn’t just due to rain; it can also be caused by snow and ice in extreme cold climates. Snow can melt, get in under the wall system, and creep into the building. While ice dams and icicles occur on the outside, ice can also be found on the inside. This problem is related to the breathing issue, since humid air is being driven out into a cold space where it can condense and cause moisture damage.
The final vital sign to look for is the heartbeat (i.e., the mechanical system) and how well is it operating. Make sure the HVAC system is not only heating and cooling adequately but is also controlling the humidity level, as well as pressurization and direction of air travel. Data loggers, another essential tool in assessing your building, can be used to help ensure proper control of the mechanical system. They send information on relative humidity and temperature, and can also act as moisture meters to tell whether the material they're fastened to is getting wet.
Looking at these nine vital signs can be helpful in determining whether your building is at risk of moisture damage. When dealing with mold and trying to assess a building, it's important to first do a thorough inspection. This often requires a third party who is knowledgeable about where mold can be found in a building. Be sure this person or firm is properly qualified. Determine whether your jurisdiction has any requirements for mold assessors and mold remediators to be licensed. In some jurisdictions, the two cannot be the same person. (This law was instituted by a number of jurisdictions to avoid the
fraud that had become rampant in the industry as the mold scare progressed from the 1990s into the early 2000s.)
Review any documentation, such as maintenance logs or repair records, in concert with other tools to determine where the mold might be occurring. If you're dealing with brand standards, make sure they're adapted for your climate. If you’re just beginning the design or construction process, a QA program is recommended, along with peer reviews, 3-D details, mock-ups, field tests, and possibly the use of data loggers.
If you are unlucky enough to find out that you do have a mold problem in the building, make sure that you use good consensus guidelines during remediation. The IICRCS520 has become one of the better-known standards for dealing with mold remediation. The EPA also has mold remediation guidelines that you can use.
Employ professionals to do the actual remediation. They should ensure that the proper protective equipment is used to protect your building from any mold that may be released during the demolition and remediation process.
About the Author
Richard Scott-AIA, NCARB, LEED AP, a Senior Forensic Architect at LBFG with more than 35 years’ architectural experience and an expert in building envelopes, has conducted more than 500 forensic investigations and has helped solve some of the most complicated mold and moisture failures in the world.
LBFG has provided mold and moisture diagnoses and solutions for buildings to owners, contractors, and developers worldwide. The firm has project experience in the U.S., Canada, Mexico, the Caribbean, Central America, the Middle East, Southeast Asia, and Europe. Contact us at firstname.lastname@example.org or by phone at (407)467-5518. Visit our website at www.buildingforensicsgroup.com