Adhesives and Sealants Transitional Connections

Posted on 9/6/2018 11:15:42 AM By Paul Bertram
  

System installation defects and lack of assembly/system building science impacts performance of sealants and adhesives.

In my travels this year, I have started to photograph projects under construction and then post on Linkedin (see this link to related postings - https://www.linkedin.com/in/pbertramjr49/detail/recent-activity/) for opinions of potential failures due to inadequate installation of components making up the exterior enclosure.

Most adhesives and sealants are critical to sealing up the enclosure for maximum performance in reducing air and moisture infiltration/exfiltration. Incorrectly installed systems can lead to air and moisture penetration to the enclosure assembly and contribute to potential latent defects. As one drives by these projects it is not hard to see theses construction defects and once wrapped with final enclosure, over time, they potentially become latent defects.


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Comments on these photos ranged from the Linkedin Post:

  • The product works; the installation doesn’t.
  • The key work is education. In construction, education is the end result of Building Science. My definition of Building Science is a simple equation; Information plus communication divided by scrutinization equals education
  • 4 out of 5 times installation is done by the carpenter, his helpers or the GC self-performed it, regardless, WRB installing should be a licensed trade and inspected by a third party that is highly trained.
  • Some of the moisture problems in the photos are coming from the improper detailing of the window drip edge / exterior sill. 

Building science plays a key role in developing adhesives and sealants for the construction industry with functional performance of intersecting components to reduce air infiltration/exfiltration. Many conditions, such as compatibility with other components, extreme moisture and humidity conditions, improper design/installation (per manufacturer’s instructions) impact the functional performance of these products.

Dr. Doggett (https://www.linkedin.com/in/m-steven-doggett/) who is the Principal Scientist and founder of Built Environments, Inc. an architectural & building science consulting firm specializing in building enclosure design is also posting many examples of failures related to transition connectivity.

In his article Unintended Consequences Of Self-Adhered Flashing, Dr. Doggett specifically addressed self-adhered membranes that have the potential to create unintended problems when moisture accumulates between the flashing and sheathing due to moisture leaks or as a result of exfiltration from poorly-sealed rough openings.  He notes the problem is worse in cold climate construction as a result of low-permeability interior vapor retarders that restricted inward drying.

He concludes that while these materials provide effective workable solutions to many of the industry’s pervasive problems. The potential for moisture entrapment warrants careful design considerations, especially in cold climates and interior environments subject to high humidity and installation as detailed.

I would add that the current trend of increasing extreme weather events also adds to the complexity of designing assemblies that can withstand these ever changing conditions.

Manufacturers of adhesives and sealants, through continuous improvement, have an opportunity to build relationships with design professionals, specifiers, contactors and subsfor development ofeducation programs for all phases of the project.

How are these failures relative to manufacturers of adhesives and sealants?

All producers have CSI specifications and meet compliance requirements. ASC has guidelines on types of adhesives and sealants. ASC also offers various education programs to on the science of adhesion and bonding to name a few. Education is the critical link and includes programs directly from the manufacturer and from the Adhesive and Sealants Association to reduce these failures.

There is a high probability of product liability regardingincorrectly installed materials.Of course “it depends” but manufacturers have deeper pockets than most installing contractorsand you can be assured of being involved in dispute resolutions.

In a recent 2018 Global Construction Disputes Report 2018: Does The Construction Industry Learn From Its Mistakefrom ARCADIS reported on Global construction disputes. The value of disputes in North America dropped slightly in 2017. However, the average time taken to resolve these disputes in the region increased slightly by two months in 2017 and far exceedsthe global average of 14.8 months.

Some proactive owners are incorporating High-Impact techniques that include risk workshops that gathers project participants from multiple stakeholders in a “high powered” brainstorming session that identifies potential problem areas months and years before they might occur.

This is the basic definition of Collaborative Design and it certainly would be to manufacturers’ best interest to be involved in these discussions to help mitigate potential problems including installation.

Elias Saltz, CSI, CCS identifies in an article on Prevention of Construction Failures typical failures are a result of design error (Including building science/physics), installation failure,and material failure.

For greater clarity, 3 Dimensional drawings, in place of 2 dimensional, are recommended by most enclosure specialists to show exactly what adhesives/sealants, where and how they are to be applied to the assembly or system.

Elias also wrote about types of Installer Qualifications. In Section 01 40 00 of the CSI formatted specification “Quality Requirements,” includes the following general, subjective requirement for installer qualifications:

“Installer Qualifications: A firm or individual experienced in installing, erecting, applying, or assembling work similar in material, design, and extent to that indicated for this Project, whose work has resulted in construction with a record of successful in-service performance.”

There are there are several ways that installers may be required to become qualified, including:

  • Certification by an industry association such as:
    • aaba – Training Certifications for air barrier installers:
      • Self-Adhered & Fluid applied installer training course
      • Quality Assurance Program Administrators Course
    • Successfully completing a manufacturer’s training or certification program.
    • Certification
    • Installer is capable of providing a system that is covered by manufacturer’s warranty.

 

Possible Action Items

The issues regarding building science and how adhesives and sealants are subject to failures due to improper specification specific to project design, challenging conditions along with improper installation is a topic for further discussion. Failures are a huge challenge and present a strong business case to engage building scientists in running models of adhesives and sealants functional performance under various conditions and material constructions to mitigate potential latent defects. These failures may also require supply chain performance evaluation.

For greater certainly in performance specify “In Laboratory” and Field mockup standards testing for air and moisture and include the installer supervisor for proper installation of the adhesives and sealants.

The issue of improper design, specification and installations of adhesives and sealants in an assembly/system is also one of the reasons why Off-Site constructions are gaining consideration due to better Quality Control/Assurance in a controlled environment. Of course, these assemblies have to connect up out in the field that requires additional attention to detail.



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