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.

Part of the problem rests in the fact that during the Great Recession, a good number of the largest design and construction firms lost many key employees. As a result, the institutional knowledge that had formerly kept construction projects out of trouble disappeared along with these key thought leaders.

Since firms can no longer rely on legacy partners to deliver this information to the next generation, they must find good alternatives quickly, both for the sake of their projects and for the very viability of their own future. As an industry, we know that we can prevent buildings from failing because we are able to fix them once they do fail.

One of the best and quickest fixes (and preventative measures) is the implementation of a third-party peer review. A peer review makes sure that design and construction firms get the right information to the right people at the right time, allowing them to address any potential issues from the earliest phases of a new building project.

A firm should establish and distribute specific written design and construction guidelines at the project’s inception, and then use periodic peer reviews throughout the design and construction process to compare progress against the original design and construction guidelines. When implemented correctly, these steps become the foundation for a practical model for improving the performance of both new and renovated buildings.

The premise behind this model is that at each stage in a project’s life (design, construction, and operation), crucial decisions must be made to avoid problems and control costs. When such choices are applied properly, the incidence of building problems substantially decreases and the initial construction cost or schedule is not affected. These achievements are made possible by eliminating many overly redundant and unnecessary building system components or procedures that often add nothing to the ultimate performance of a building.

Let’s look more closely at the importance of this model by examining a case study from modular construction. The emergence of modular construction as an option for new construction is becoming mainstream. The reasons have been reported on well. What has not been reported as widely, however, is that the modular construction industry has had its share of mold and moisture problems, especially in warm and humid climates like the Southeast U.S. Both wood frame and steel frame modular construction have experienced problems with condensation in crawl spaces, marriage walls, and ceiling-to-floor cavities, resulting in deterioration of the wood and wallboards, corrosion of metal floor pans, and proliferation of mold.

The greatest risk of modular construction failures has occurred when this type of construction and delivery is used for hotels, student housing, senior living, or soldier housing – in general, facilities that are domicidal or multi-family in nature. The reason is because of inherent similarities in requirements for the living units of these types of facilities, such as an individual cooling/heating unit, bathroom exhaust, and some sort of central HVAC make-up air system. In addition, the abundance of modular boxes in these kinds of buildings increases the number of marriage wall interior cavities and ceiling-to-floor cavities that otherwise might not be required in other types of modular construction.

The premise behind this model is that at each stage in a project’s life (design, construction, and operation), crucial decisions must be made to avoid problems and control costs. When such choices are applied properly, the incidence of building problems substantially decreases and the initial construction cost or schedule is not affected. These achievements are made possible by eliminating many overly redundant and unnecessary building system components or procedures that often add nothing to the ultimate performance of a building.

Let’s look more closely at the importance of this model by examining a case study from modular construction. The emergence of modular construction as an option for new construction is becoming mainstream. The reasons have been reported on well. What has not been reported as widely, however, is that the modular construction industry has had its share of mold and moisture problems, especially in warm and humid climates like the Southeast U.S. Both wood frame and steel frame modular construction have experienced problems with condensation in crawl spaces, marriage walls, and ceiling-to-floor cavities, resulting in deterioration of the wood and wallboards, corrosion of metal floor pans, and proliferation of mold.

Imagine this scenario:

  • A modular construction unit had inherent interior hidden spaces that made it difficult to control the infiltration of outdoor air. (In wood frame modular construction, this is typically the cavity between modular boxes, while in steel frame modular construction it is usually the spaces between modules.) These interior cavities provided a pathway for air flow to not only readily enter the building, but also to travel long distances throughout the building, washing interior surfaces. This caused direct condensation and/or raised surface conditions that led to physical damage and mold growth on wood framing and interior drywall.
  • Each modular box as it came from the manufacturer had been designed and constructed in a vacuum of the requirements for the overall performance of the building. This was especially true in the HVAC system design and construction for building pressurization. In modular box design coming straight from the factory, both the cooling/heating unit and the bathroom exhaust are generally dependent upon the separate common area HVAC system for make-up air. This factor is often overlooked in the design and construction of modular facilities. In fact, the pressurization of the overall building is dependent upon the pressure characteristic of each interior space, whether it is an occupied space or the space between two modular boxes. Similarly, the air leakage characteristics of modular construction buildings is not only dependent upon the leakage rate of the modular box itself, but also upon the leakiness between and around the compartments that make up the building (both occupied spaces and the wall cavities between the modular boxes).
  • The modular design and construction used pilings as its foundation. The resultant crawl space adversely impacted the ability to control condensation and outdoor air flow in and throughout the building.
  • The modular design and construction process had a modular box versus base building conflict inherently built into how it was delivered. Modular boxes are designed and manufactured by a separate entity from the one that designs and constructs the base building. The crawlspace, roof, attic, exterior cladding, and HVAC system are more often than not designed by one entity and constructed by another.

Inspections for code compliance were different for the modular construction versus the base building construction. This often varies depending on the jurisdiction in which modular construction is either manufactured or constructed. In Florida, for example, modular construction is governed by the Department of Community Affairs (DCA). This includes inspection of each modular box before it leaves the manufacturing facility. The base building, on the other hand, is inspected by the local code official. This individual does not inspect the modular box since it has already received the DCA inspection and certification. While both governmental agencies rely upon the same building codes, the silo inspection process competes with a more holistic process that has the overall building performance as the overarching goal.

You Can’t Fake the Funk

The case study above was specific to modular construction, but the general principles and challenges involved are common to today’s design and construction industry overall. So how can designers and contractors avoid these problems? Below are four points every architect and contractor should be aware of to avoid a catastrophic mold and moisture building failure:

  • Buildings should not be designed in silos. Despite advances in technical understanding and higher standards for building performance (like building envelope air tightness), design tasks such as building envelopes are still being completed in a vacuum of other critical disciplines. On a recent project, the facade consultant was asked how the design interfaced with the overall building pressurization requirements established by the HVAC design. The answer: “We don’t consider that in our design. They do their thing and we do ours.” Keeping silo design from happening on your next project means more than using tools like BIM. While BIM is good for making sure field conflicts don’t occur, there is a lot more to address concerning multidisciplinary building performance. Careful coordination between disciplines like the architect and HVAC designer must occur to ensure that problems like compromised wall systems, building air infiltration, and dehumidification do not become catastrophic.
  • Develop a set of design and construction guidelines specific to the project. If pertinent, include each problem that has been analyzed and solutions that were provided. This step helps to avoid corporate amnesia by allowing for lessons learned to be pushed forward to new team members, and for a transfer of knowledge from past expertise to become a part of future decisions. Get the right information to the right person at the right time. It doesn’t do any good for lessons learned to stay among only those who attended expert depositions. This information needs to be passed on to those who need it most: the design and construction teams.
  • Bring forward the experts early on in the process. Use periodic peer reviews to make sure that the information provided to the design and construction teams is passed along at the right time. These critical project pressure points can virtually guarantee success or failure depending upon what decision is made.
  • When problems arise, minimize occupant outrage as quickly as possible. This becomes one of the greatest influencers on the cost of fixing a building. J. David Odom, Senior Consultant with LBFG, found this out in the early 90s with projects like the Martin County Courthouse. Handling occupant confidence (or lack thereof) is one of the key areas any designer or contractor needs to master. If they don’t, they will encounter costs that are multiples of what the fix should be.

Building performance can be highly predictable. Use this to your advantage by being wise about how you approach and manage your next endeavor. Hope is important for many aspects of life, but when you are in the design and construction business, hoping for something to work is never a good premise for your project.

About the Authors

Contact us at g.dubose@libertybuilding.com or by phone at 407/467-5518:  Mr. George DuBose-CGC, Mr. Steven Gleason-PE, and Mr. Nate Sanders-CIH are all of Liberty Building Forensics Group (LBFG). LBFG has provided mold and moisture diagnoses and solutions for buildings to owners, contractors, and developers worldwide and has project experience in the U.S., Canada, Mexico, the Caribbean, Central America, the Middle East, Southeast Asia, and Europe.