Moisture damage around the bathroom exhaust fan from reverse air flow through the exterior wall cap

 

But why?! Hasn’t there been enough lessons learned through moisture/mold construction litigation in the hospitality, multi-family apartment high rise, student and military housing sectors that show that dumping the make-up air to the corridor is a risky proposition? Apparently not?! This concept of make-up air delivery to a corridor has been and continues to be a living unit moisture and mold risk because the make-air cannot reach each occupied room on each floor for purposes of ventilation, pressurization and make-up air for exhaust. Many times, it is intended that this makeup air will reach each occupied rooms across each room’s door undercut. But it can’t because resistance to airflow, the amount of required makeup airflow to each room, the size of the door undercut, and the internal and external pressures on the rooms and corridor. In addition, test and balance can’t accurately measure it.

Continue Reading Hot, humid climate makeup air conundrum: The moisture and mold risks that developers, designers and installers continue to take

By George H. DuBose, CGC; Charles Allen, Jr., AIA; Donald B. Snell, PE, Cert, Mech. Contractor, CIEC; and Richard Scott, AIA, NCARB, LEED AP

Sign up for our free March 6 webinar on “A Project Peer Review: The Single Most Important Factor in Reducing the Risk of a Mold and Moisture Lawsuit in Your Next Project”.

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Figure 1: The water-based mastic stayed wet (tacky to the touch) for weeks because the covered ductwork did not allow the mastic to dry, resulting in mold growth.

Those involved in the development of most sustainable green buildings typically use innovative products and implement new design and construction approaches.

The intent of these new materials and procedures is to achieve a structure with reduced negative environmental impact, both during construction and throughout the building’s life. These ambitions have now become a part of the International Green Construction Code (IgCC), but have their origin in early green rating systems and in early versions of codes like CalGreen.

While the IgCC has been adopted in some jurisdictions as an alternative measurement for sustainable buildings, rating systems such as LEED® v4 have become more widely used. Both approaches, however, have had a similar influence on design, product selection, and construction means and methods. Continue Reading Innovation Isn’t Always Better: The Impact of Low-VOC Mastics on Mold Growth and Corrosion in Ductwork

peer review webinarNot all buildings are created equal. In fact, some fail at alarming rates, often soon after being commissioned. Some building failures occur at a high rate of frequency but result in minor consequences, while others are infrequent but lead to catastrophic results, such as significant mold and moisture problems.

What is the difference between building success and failure? Experts at Liberty Building Forensics Group have learned firsthand that there is one overarching factor: conducting a peer review. They will be conducting a free webinar on this topic on Tuesday, March 6 from 1:15pm – 2:15pm. It is AIA-CES registered for 1 LU-HSW. Register here: https://lx375-800425.pages.infusionsoft.net.

A peer review introduces into the design and construction processes a subject matter expert who understands that there are less-costly options that can still achieve the desired project results. Continue Reading The Single Most Important Factor in Reducing the Risk of a Mold and Moisture Lawsuit in Your Next Building Project

By George H. DuBose, CGC; Steven R. Gleason, P.E.; and Charles Allen, Jr., AIA

While it’s accurate that truth can certainly be stranger than fiction, it is equally strange that so many in the design and construction industry perceive myths as truth, especially after they have been disproved as false time and time again.

In our work resolving mold and moisture problems in hotels and resorts, Liberty Building Forensics Group (LBFG) experts have discovered certain faulty beliefs surrounding hotel performance in coastal zones that are leading to building failures which are often catastrophic in scope. Below is one such myth related to waterproofing, followed by an explanation of why it is false as well as a first-hand case study supporting this position.

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Figure 1: Despite the presence of a waterproofing membrane on the elevated concrete slabs, water intrusion occurred through the terrace levels into the spaces below, infiltrating via penetrations and cracks in the slab.

Myth – Water damage can be avoided in hotel design as long as some type of waterproofing membrane is installed over a concrete slab.

Truth – Unfortunately, the issue is not as simple as that. In fact, many factors must be considered when waterproofing a concrete slab base. Using a waterproofing membrane over a concrete slab, which is often topped by a mortar bed and stone or similar overburden, is just the starting point. Continue Reading Fact vs. Fiction: Hotel Waterproofing in Coastal Zones

Building Envelope & HVAC Interaction
in Warm, Humid Zones

By George H. DuBose, CGC; Richard Scott, AIA, NCARB, LEED AP; and Donald B. Snell, P.E., Cert. Mech. Contractor, CIEC

building failures
This high-rise resort in Central Florida underwent a $9.5M remediation only to have the problem come back the first summer after it was complete.

Certain faulty beliefs surrounding building performance in warm, humid zones continue to persist in the design and construction industry – and the interaction between building envelopes and HVAC systems is no exception.

Unfortunately, the fact that many architects and engineers rely on such myths as gospel truth during building design has inevitably led to building failures that are often catastrophic in scope.

Below is one prevalent myth our experts at Liberty Building Forensics Group (LBFG) have encountered through their extensive work resolving mold and moisture problems in hotels and resorts. The myth is followed by an explanation of why it is false, as well as a first-hand case study supporting this position.

Myth: A building envelope can perform effectively on its own without any help from the HVAC system. Continue Reading No Building Envelope is HVAC Failure-Proof

Myth―An unproven or false collective belief

By J. David Odom and Richard Scott-AIA, NCARB, LEED AP of Liberty Building Forensics Group and Norm Nelson of CH2M

If PTAC units were a federally regulated drug, then each equipment sale would include a list of side effects and cautionary notes. Unfortunately, the opposite is true—each PTAC buyer is provided with a list of unproven expectations and myths. It is these unproven PTAC performance myths, enduring for decades, which have contributed to an outsized number of moisture and mold problems.

Over the past 30 years, our building experts have investigated hundreds of hotel moisture problems (involving over 100,000 guest rooms) and in the process, have seen three repetitive problems that appear to be ignored by the hospitality industry:

  1. PTAC units cannot ventilate interior spaces.
  2. PTAC units cannot pressurize hotel guest rooms.
  3. PTAC units are often ineffective in dehumidifying hotel guest rooms, especially when outside conditions are hot and humid.

Even though PTAC units cannot provide these features, the myths are that hotel industry, including owners, operators, developers, contractors, and designers, believe that they can. Continue Reading The 3 Myths of PTAC Units

moisture problems

Suppose there was a tool that could predict, before a single penny was spent on construction, the likelihood of whether your building would fail. Not only that, but this tool could also provide you with enough information to make significant design changes that would dramatically decrease any risk factors. Would you be interested? Of course you would.

At the risk of oversimplifying a complex process that contains multiple variables, we believe we have created such a tool. The following moisture prediction charts have been adapted from a mold and moisture manual Liberty Building Forensics Group developed for Disney Corporation in the early 1990s. Over the past two decades, they have been beta-tested on literally thousands of hotels, and have proven time and time again to be as true today as they were 20 years ago.

Although the charts were created with hotel guest rooms and wall cavities in mind, the general principles demonstrated would hold true for most buildings. Hotels just happen to be the simplest commercial building structure, so they were the easiest to beta test. Continue Reading The Incredible Predictability of Moisture Problems

When Your Student Housing Property has Water Intrusion and Mold,

the Last Man Standing Could Be the Loser!

 

An increasing number of legacy buildings, including aging student housing complexes, are experiencing water intrusion and mold-related damage that can be traced back to fundamental design and construction defects. The buildings have experienced water intrusion that, in many cases, results in hidden damage to the structure.

While there may be some signs of the water intrusion inside the student apartments, the damage may not be obvious to the management firm. Unfortunately, by the time the damage is found, the statute of limitations for original designers and contractors is long gone. As a result, the buck often stops with the liability insurance of the current student housing management firm. This firm will be considered the last man standing.

Regardless of where the root problem originated, management firms are being held responsible for these defects if they haven’t taken steps to protect themselves. Managers of older student housing complexes who find themselves in this precarious position should understand the ways to manage their risks.

 

Continue Reading Campus Community Management Firms, Beware!

Avoid Catastrophic Mold and Moisture Problems in Hot, Humid Climates Due to Air Barrier Standard Confusion

 

By George DuBose, CGC; Richard Scott, AIA, NCARB, LEED AP; and Donald B. Snell, PC CIEC

 

Imagine the following scenario: you just designed your newest project to meet the most current whole building air leakage standards, and your mechanical engineer subconsultant has designed an HVAC system that includes one of the latest energy recovery strategies. Both factors are intended to meet high energy efficiency goals, making you proud that your firm is doing its part (amongst other things) to minimize your impact on the climate change problem.

Continue Reading Till Death Do Us Part: Preventing a Facade and HVAC Divorce When It Comes to Air Barrier Performance

As the building and construction industry continues to come out of the hibernation that has been the norm since 2009, it unfortunately appears that it’s déjà vu all over again when it comes to water-related building failures. As new buildings are being constructed, the same design and construction deficiencies of the past are being repeated, leading to (often catastrophic) mold and moisture problems.

 

It may seem somewhat unbelievable that the industry still finds itself making these same basic mistakes time after time. After all, preventative solutions to these issues have been understood and well-published for many years.

 

Continue Reading Design and Construction Amnesia: We Have Lost our Minds and it is Causing Catastrophic Mold and Moisture Building Failures