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


Just months after completing refurbishment on a 300+ room resort, the owner of a luxury coastal vacation resort began to wonder if he had entered into the Twilight Zone when mold and moisture problems suddenly emerged in numerous guestrooms. He was perplexed that this problem was cropping up now despite the fact that he had owned and operated similar properties for many years. Never in all that time had he ever experienced moisture-related issues.


Why was the problem occurring at this point? What was different?

Continue Reading Has Coastal Zone Hotel Construction Become the Twilight Zone for Mold & Moisture Control?


What Did You Miss? What Did Building Owners, Developers, and Contractors Miss?

Richard Scott, AIA – Vice-president, Senior Forensic Architect

Over 15,000 architects attended the recent AIA 2017 National Conference on Architecture (A’17) in Orlando, Florida. What did they learn that you missed?  As a speaker and attendee, the following are the top three things I learned at this invigorating Conference:

1. Building forensic sessions were well attended, and still scare architects. And building forensics should still be scaring owners, developers, and contractors. There were over a dozen sessions on building envelope technology, disaster avoidance, and commissioning, some presented by forensic experts. Even the 7 AM forensic sessions, such as my Liberty Building Forensics Group (LBFG) presentation on air barriers, had over 100 attendees even though it was concurrent with 19 other sessions. No one likes a building failure unless of course, it is someone else’s failure.  So advice on prevention, based on failure case studies, drew many interested parties, questions, and concerns. Those who did not attend may want to at least obtain the handouts from forensic sessions.


LBFG’s session not only presented the complexity and difficulty of specifying and constructing air barriers but also the checkered and uncoordinated landscape of code and industry standard requirements (the session handout is available on the AIA A’17 app as well as LBFG’s website, www.buildingforensicsgroup.com). LBFG’s business is investigating and litigating building envelope and HVAC failures. The combination of failed envelope air barriers and failed HVAC leads to exponential damages to building facades, structures, finishes, and contents.


Continue Reading The Top 3 Things I Learned At This Year’s AIA National Conference on Architecture


Here is an all-too-common scenario: A design and construction team is awarded a new hotel project. The design and construction standards are passed on to the team. The team adheres exactly to the requirements of exterior wall design and HVAC system design only to discover during final stages of construction that the actual performance of the design is vastly different than expected.  Unsuspecting hotel design and construction teams need to heed the warning: “Rigid adherence to hotel design and construction standards without factoring in specific regional and climatic conditions can result in significant mold and moisture issues in new hotel construction.”


Continue Reading Clash of the Titans: When Hotel Design and Construction Standards Cause Catastrophic Mold Problems

Performance criteria for the window do not always mean that the same criteria are required for the window unit and all of its accessories – like subframes.


Specifiers mistakenly assume that the performance criteria indicated for the window unit itself applies to the entire assembly, including accessories. This can be problematic, particularly if the accessories are a critical element in the water resistance of the assembly (e.g. subframes and receptor systems). Designers typically indicate stringent performance requirements for the glazing system but fail to properly design or detail the interface between the glazing and adjacent construction. Field testing typically includes this interface at the test pressures specified for the window and leakage is common. Differentiating between window and interface leakage is difficult. Operable window and door components are not required to be tested in as stringent a manner as fixed components; however, specifiers often indicate the wrong test procedures and/or field testing is performed erroneously using the wrong procedures, resulting in false test failures.

The mission of designing high-performance buildings that promote sustainable objectives has led to new success stories but has also revealed vulnerabilities for potential mold and moisture failures.


The interaction between a building’s HVAC system and envelope creates an unusually high-risk area. Any deficiency in either system can cause dramatic, building-wide moisture and mold problems. Through the emergence of high-performance buildings combined with the use of certain new green products, designers and contractors have inadvertently created high-risk buildings when, in fact, the goal should be to develop high-performance buildings with the lowest possible risk of failure.

Continue Reading New Online Course Demonstrates How to Design and Construct High-Performance, Low-Risk Buildings While Avoiding Catastrophic Mold and Moisture Problems

In our work as forensic architects and engineers, we are regularly involved in litigation over stucco failures, including hotels and high-rise condo complexes. (For this article, ‘stucco’ refers to traditional portland cement plaster direct-applied to a masonry substrate, rather than using lath.)


Myths abound around stucco cracking. In truth, it is not abnormal to have some cracking with stucco, much of which can be relatively harmless. The key is paying attention to the types of cracks, and minimizing any significant issues that might lead to actual failure, including debonding, water intrusion, and mold problems. It is not a good idea to pack out stucco so thick it may end up debonding and falling on those Bentleys (and their owners) below.


Myth #3: Direct-applied stucco is easily packed out to meet a finished plane.

Continue Reading Stucco Myth #3: Direct-applied stucco is easily packed out to meet a finished plane