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

photo credit: Scott Ehardt


 

You are a defendant in a lawsuit. The crime? A moldy, moisture-damaged building. What you don’t want to have to say during deposition while under oath, “Lordy, I hope there is tape!”

 

Continue Reading Lordy, I KNOW there’s tape!

The emergence of #modular construction as an option for new construction is becoming mainstream. The reasons have been reported on well. However, what has not been reported is that the modular construction industry has had mold and moisture problems, especially, when used in a warm and humid climate like the Southeast US. Both wood frame and steel frame modular construction have experienced problems with crawl space, marriage wall, and ceiling to floor cavity, condensation problems that have not only resulted in deterioration of the wood, corrosion of metal floor pans, deteriorate wallboard and mold.

 

The greatest risk of modular construction failures has been seen to be when this type of construction and delivery is used for hotels, student housing, senior living, soldier housing, type facilities. In general, facilities that are domicidal or multi family in nature. This is because these types of facilities have inherent similarities in a living unit that requires both an individual cooling/heating unit, bathroom exhaust, and some sort of central HVAC make up air system. In addition, there are many more modular “boxes” in these kinds of buildings increasing 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 nature of modular construction makes it difficult to repair once it is found to be damaged. Sometimes, the damage can be such that the modular building has to be deconstructed to remove damaged materials and then re-designed and re-constructed using conventional methods. This essentially makes the modular construction advantages dissolve away as the building gets converted to a traditional “stick” building.

Continue Reading Deja Vu All Over Again: Risks for Moisture and Mold Problems in Modular Construction

 

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

 

After over 25 years of figuring out why buildings end up as catastrophic mold and moisture building failures – there are some apparent truths that have remained seemingly unchanged.

 

 

Buildings should not be designed in silos (but they still are). Despite advances in technical understanding and higher standards for building performance, like building envelope airtightness, the design task for the building envelope is still being completed in a vacuum of other critical disciplines. On a recent project, the facade consultant was asked how their 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.”

 

Continue Reading You Can’t Fake the Funk: After 25 Years of Consulting, Here are Three Forgotten Truths about Mold and Moisture Building Failures

 

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

The theory behind design and construction (D&C) standards is to provide assurances that the hotel is built to requirements that meet the brand’s expectation for aesthetic, operational, and building performance. D&C standards portray themselves as a repository of lessons learned and of what should be done (and, by implication, what should not be done) to make the hotel work. However, theory proves contrary to actual practice in this case because D&C standards are developed on a global basis. They typically do not take into consideration specific needs and limitations of regional climates. In fact, it has been found that these  D&C standards often don’t comply with recommended building practices for certain climates at all. These violations in the D&C standards have been shown repeatedly to result in extensive and costly mold and moisture problems in hotels.

 

In the case of a 140-room hotel in a warm and humid climate in Texas, the hotel began to experience significant mold and moisture problems that resulted in more than $5 million of damage claim against the general contractor. D&C standards for the hotel required that the mechanical system provide roof top units (RTUs) for conditioning of the corridors with 10% additional outdoor air for building pressurization. Liberty’s measurements of relative pressurization confirmed the cause of visual evidence of mold growth behind the VWC. With all HVAC systems operating (RTUs, PTACs, and toilet exhausts), the guestrooms were and wall cavities were under high negative pressure relative to outdoor air. Even with the toilet exhaust fans turned off, guestrooms were barely under positive pressure, and some were still under negative pressure (see Figure 1). Negative pressurization, as a result of misapplication of brand standards, results in drawing in of warm, humid air which leads to mold growth.

 

Continue Reading Brand Demands: Can These Be The Cause of Catastrophic Mold Problems?

“Hmm, let me think about that. Here is what I found: According to Liberty Building Forensics Group (LBFG) they have been seeing an alarming trend in moisture and mold problems in new low to mid-rise wood frame multi-family buildings.”

 

With improvements in wood framing technology, there has been a remarkable increase in using wood for low to mid-rise apartment buildings, dormitories, and residential condominiums. Often the first floors are podiums of steel frame, but upper floors are exclusively wood structure. Mold and moisture problems during construction are showing up due to external influences (rain) as well as internal sources (wet applied materials). Contractors must deal with repairing damage and remediating the mold to satisfy risk averse owners/developers/lenders.

 

Continue Reading “Alexa™, What Building Type Today has the Most Risk of Moisture and Mold Problems?”