Premier episode introduction to Podcast series

Everything Building Envelope is a dedicated podcast and video forum for understanding the building envelope. Our podcast series discusses current trends and issues that contractors, developers and building owners have to deal with related to pre and post construction. Our series touches on various topics related to water infiltration, litigation and construction methods related to the building envelope.

Premier episode introduction to Podcast series;
(Released March 1, 2015)

1. Background of host Paul Beers
2. The impact of hurricanes and GCI’s involvement in establishing new building codes
3. Who is GCI and the services we offer
4. Goal: To discuss topics related to the exterior building envelope.
Best Practices, Emerging trends, Hazards

 

Water Penetration Testing

By Shauna Sproul

Field testing of building exteriors for water penetration, frequently simply called “water testing,” is essential for identifying manufacturing and construction defects in windows, doors, skylights, and other openings in the building envelope.  For example, a window might leak due to problems with installation of waterproofing and perimeter sealant details, or because of improper materials or methods used by the plant during manufacturing.

Many clients come to us for one-day water testing, conducted upon the completion of construction.  While such tests are certainly useful and productive, earlier engagement in the process can help contractors and building owners avoid costly, more complex issues frequently uncovered during one-day tests.

Water testing determines the resistance of manufactured windows, curtain walls, skylights, and doors to water penetration.  Proper water testing methodology follows the protocols set forth in the American Society for Testing and Materials (ASTM) E 1105 standard.  Under that standard, water penetration failure occurs when water leaks beyond a plane parallel to the vertical plane of the assembly’s innermost projection, not including interior trim and hardware.

While the test is a field version of laboratory certification tests and simulates the conditions of a wind-driven rain storm, laboratory testing itself of glazing systems and other building assemblies cannot reflect field testing results.  Materials and methods used in construction can significantly affect their performance in actual use.  Events occurring between shipping and installation as well as environmental influences can all have a negative impact on component and system performance.

How it’s done

Water testing measures penetration by applying water to the outdoor face and exposed edges of the tested assembly with a static external air pressure higher than the pressure on the indoor face.  Not only will it determine resistance of assembly components themselves, it can also reveal leakage between those assemblies and the surfaces in which they are installed.  While a manufactured component may successfully meet ASTM E 1105 water testing criteria against leakage into the building itself, water may penetrate an assembly, leading to degraded performance of materials.

Water testing is typically conducted by sealing a chamber to the interior face of the assembly tested, then exhausting the air from that chamber to produce pressure differentials similar to those produced by weather. A rack of calibrated water nozzles sprays water at the proper rate on the exterior surface.  The air pressure differential may be uniform (constant) or cyclic (varied).  It’s important to note that air pressure varies greatly across the building envelope and the water testing methods applied should incorporate an understanding of that variation.  Though water testing uses similar equipment, air infiltration measurement is not included as part of the procedure.

When to test

Water testing may be conducted any time between initial assembly installation and construction completion.  However, earlier and repeated testing is advisable for multiple reasons.  Tests conducted upon initial installation provide easier inspection of interior surfaces for penetration and to identify the precise point(s) of penetration.  More importantly, with early testing, fabrication and installation problems can be discovered at a time when corrections are more easily made and at much lower expense since no interior wall components must be removed and replaced.

While building codes may not require it, every new construction project should be water tested regardless of size.  No project is too large or too small.  Many smaller projects don’t incorporate water testing simply to keep construction costs lower.  Any financial advantage disappears, however, if windows or doors start to leak and water testing reveals hidden problems.  The cost of water damage and remediation can greatly exceed the cost of early testing and consultation.

The ideal time to start water testing is when the first few glazing systems are installed.  Not only are problems more easily detected, design and potentially recurring issues can be corrected going forward.  Contractors and owners who rely on one-day water testing only when the project nears completion may be unnecessarily adding risk and cost to their construction projects.

Better still, engaging the full scope of services of a building envelope consulting firm like GCI can help identify water penetration and other building envelope issues at the planning and specification stage.  It simply makes more sense to solve water issues in a project’s development and before testing, not after leakage has occurred in a nearly completed building and added water damage to the combined problems.  Some potential leakage problems can be solved before windows and other assemblies have even been ordered.

The ASTM Standard is used for both the one-day testing and in the testing we would do on a full scope project, yielding the same results.  The concern is we cannot always fix the issues easily with a one-day test because the building is closed up and all the windows have already been installed.  In a full scope job we would test early enough to get the issues resolved before all the windows would go in.

Glazing System Replacements

By Jason Bondurant

Replacing windows or doors is no small task. Just ask any building owner or manager who has faced the challenge. What may seem simple at first becomes increasingly complex, once all the factors involved are considered and construction starts. It goes beyond material costs, building codes, and contractors. You also must take into account who will be designing and managing the project. A bad installation can result in more problems than you started with. You need a collaborative approach, with everyone working together with the single goal of getting the job done right using the right products.

Building owners or managers will have to make many critical choices which will directly affect the success of the glazing replacement project.

Choosing the right time

Many people think the time to consider window replacement is when problems related to age and wear – wind and water leaks, paint, corrosion, mold and mildew problems, operating difficulties – become obvious. It might not be a good idea to wait that long, though, especially if your building is 20 years or older or more. Besides, the benefits of modern glazing systems show up in ways far beyond cosmetics. Consider that once popular single-pane aluminum slider windows have a heat loss rate approaching 50 percent even when properly installed.

The lessons learned from damage caused by Hurricane Andrew in 1992 provided the turning point for building codes and construction standards in US coastal areas and elsewhere throughout the nation. The experience may have been both painful and expensive, but today’s glazing systems are windborne debris resistant, energy efficient, and free from wind and water leaks. Plus, building codes continue to change and evolve in the 21st century as materials and technologies improve and provide even more risk mitigation.

It may be easy to feel good about such advances, but they still haven’t reached the vast majority of the nation’s commercial building environment still vulnerable to high winds and windborne debris. This deficit ensures it will take many years before a significant percentage of commercial buildings are protected, even if all new buildings are fully compliant. Changes in building codes and the benefits of new glazing systems should be incentive enough to begin investigating into upgrading your windows. The cost of a new glazing system may be high but the cost of an old glazing system which is not replaced until it finally fails during a storm could be astronomical.

Choosing the right system

“New windows” likely means more than just new glazing (glass), especially for older structures. New energy standards and impact resistance standards usually me
an replacing the glazing system –  glass plus structural components, including frames and anchorage – that make up the entire window or door. Some older buildings may require upgrades to the adjoining structure so that windows and doors can be properly anchored. Improvements in building science and materials all must be taken into account during the design and planning phase to ensure the final product will continue to perform many years into the future.

Updating the glazing of older buildings to meet current code compliance often presents unique obstacles – even though construction stringently met every once-current standard. New window systems’ tight tolerances may make installation in old existing walls difficult to tie into the existing structure to make them air- and water-tight. Plus, architectural design and aesthetics are as important for reglazing as they were when the original building plans were first drafted. Some owners may be interested in modernizing their building with a new style while more often than not they would like to preserve the original design intent.

With all the recent advancements in engineering design and materials, the benefits of a new glazing system can add up quickly. Of course, the obvious advantages include being water-tight and energy efficient, plus the potential for increased resale value. But not all benefits are financial. Lower maintenance requirements, easier window use, and reduced exterior noise infiltration all contribute to owner satisfaction and comfort.

Choosing the right team

It takes the right team with the flexibility to adapt to and meet the challenges of glazing system replacement. They should be fully engaged collaborators from the start to completion, throughout the entire installation process. No matter how thorough planning may be, concealed conditions – wall and flashing leaks, for example – might not be known until the job begins. They should be excellent communicators and managers, providing the ideas and tools necessary for the smooth completion of the project.

Considering all the variables – known and unknown – in glazing system replacement, choosing the right contractor becomes critical. They must stand behind their work. Replacing a glazing system involves both exterior and interior work. For residential buildings, that means contractors will be working in somebody’s home. Not only are they obliged to keep the inconvenience and possible damage at a minimum, they must ensure the safety of the residents and workers alike. They need to be very flexible.

Choosing the right designer/manager/consultant is even more critical. You’re more likely to be satisfied and have fewer problems from start to finish when you select someone like GCI Consultants, LLC with deep experience and knowledge in all facets of glazing system replacement. Our unique skill set and expertise in all phases and aspects of glazing system installation have led us to serve as expert witnesses in courtroom litigation throughout the nation. We know which window systems and installation methods that can be relied on and the ones to avoid. Most importantly, we work closely with clients, combining innovation with building science insight to eliminate potential problems that could occur during the design and construction phase.

A large scale glazing replacement or retrofit project can be a daunting task. These properties wanted to get the job done right, so they contacted GCI Consultants, LLC:

*  The Diplomat Resort & Spa, Hollywood, Florida

*  Yacht Harbour Condominium, Coconut Grove, Florida

*  Renaissance Jaragua Hotel, Santo Domingo, Dominican Republic

*  The Alexander Hotel & Condominium, Miami Beach, Florida.

Let us know your glazing system challenges. We’re here to help from the very start.

Wet Sealing Glazing Systems to Halt Water Intrusion

By Paul E. Beers

Example of Bad Wet Seal

I recently tried a Google search for the term “Wet Seal” and found it is a clothing chain for teenage girls that filed for Chapter 11 bankruptcy in January.   I did not find any information about what I was looking for, which is a concept for sealing glazing systems in an attempt to halt water intrusion.  I then searched several major sealant manufacturers’ websites and again came up empty.  I found this to be very curious in that “Wet Seal” is a term I think most in the glazing and construction industry are very familiar with.  Finally, I found the term defined by the Glass Association of North America (GANA) as Application of an elastomeric sealant between the glass and sash to form a weather-tight seal.

Wet sealing is a remedial process.  It is not a part of new glazing system designs and should not be confused with “wet glazing,” which is when manufactured systems use sealants or tapes as part of their glazing detail.  Wet seals are applied remedially when a conventional drainage system has internal leakage that is difficult to access or expensive to repair.  In my experience with due diligence and investigations of water leakage in buildings, there are many buildings, particularly older ones, which have had some form of wet seals applied.

There are some important considerations when applying a wet seal.   First and foremost is that a wet seal usually changes the design concept of a system from collecting and draining water to a barrier system where all water is repelled at the exterior plane.  Once a wet seal is applied, if any water does enter the system, it is trapped inside with no provisions for drainage back to the exterior.  Regular inspections and maintenance are very important to identify and repair any avenues for water entry.  Water entry from surrounding areas, such as stucco, sealants, expansion joints, or even a roof leak above will also cause water to be trapped inside a wet sealed glazing system.

Window Rendering Featuring Wet Seal

When applying a wet seal, it is critical to fully seal every possible avenue for water entry.  This includes glass to metal, metal to metal and perimeter sealant joints.  Each seal must be done properly and must tie in with each other.  The finished system should basically be one continuous seal across the entire system.  Since glazing systems experience very high temperatures in direct sunlight, silicone is the only material that should be used.  Manufacturers’ recommended details for the type of silicone, joint design, profile and installation must be carefully followed.

The wet seal solutions we have designed include cutting back existing gaskets and applying silicone at glass to metal joints and using preformed silicone seals for metal to metal applications.  We always involve sealant manufacturers to review and approve our details as being in accordance with their published recommendations.  Manufacturers can also provide recommendations about needed accessories, surface preparation, proper adhesion and compatibility with abutting materials.  Some manufacturers will provide up to a 20 year labor and materials warranty when following their strict guidelines.

For wet seals to work properly they must be designed and installed to be 100 percent perfect.  If there are any deficiencies, water enters the system and becomes trapped, which can cause long term degradation of systems.  Therefore, it is critical to proof the concept in the field and have a high degree of quality control during installation.  We recommend that an in-place mockup of the repair be installed at project startup to include all typical conditions.  The mockup up should be inspected and approved and then tested using ASTM E1105 Standard Test Method for Field Determination of Water Penetration of Installed Exterior Windows, Skylights, Doors, and Curtain Walls, by Uniform or Cyclic Static Air Pressure Difference.  After successful testing of the in-place mockup, installation should be carefully monitored by a third party and the sealant manufacturer must remain fully involved.

I consider a wet seal application to be a last resort after other considerations to repair and restore a system to the original design concept are deemed impractical or too expensive.  Wet seals only are as good as their design and workmanship and last only as long as the materials continue to perform.  While wet seals can be an effective and long lasting solution, they are basically a “band-aid” to correct problems that cannot be solved conventionally.  Wet seals are often considered the easy, cost effective solution, but it really is “buyer beware” and all of the pros and cons should be carefully evaluated.

Going the Extra Protection Mile at Procacci Development’s BB & T Bank Building

At Procacci Development Corporation, one of South Florida’s leading development, construction and management companies, they take hurricane protection seriously.  In fact, the company has developed a reputation for constructing and retrofitting Class A commercial office buildings that are so strong, they meet the requirements of Public Shelters and enable tenants to continue business immediately following a hurricane.  Another plus:  Procacci is able to obtain high quality insurance with reduced deductibles – a challenge faced by many property owners throughout Florida – savings which they are able to pass onto their tenants.

The upcoming complete retrofit of the windows at the BB & T Bank Building in Doral, FL purchased by a Procacci affiliate last year is just one of many examples of Procacci’s efforts of ensuring that its buildings have a well-protected façade, critical to withstanding hurricane-force winds and flying debris.  Working in tandem with GCI Consultants, LLC, Procacci will replace all windows in the existing 4 story, 35,000 square foot structure.  The new windows are designed to withstand winds up to 176 miles per hour of a Category 5 hurricane and are made with large missile impact glass.  GCI helped assess the building façade on the 13-year old building, developed plans and specifications, consulted on the glazing selection and conducted water infiltration tests.

Procacci’s “Built Procacci Strong” initiative meets or exceeds the rigorous standards of the Zurich insurance company’s Highly Protected Risk (HPR) program.  Procacci, Zurich and GCI have collaborated on many projects, which have validated the fact that building envelope protection is good business for everyone involved.

“Tenants of our buildings sometimes have no idea about the effort and cost involved in our designing and constructing work environments that are safe and that will withstand Category 5 storms, but it’s rewarding for us to make such an important contribution,” says Philip J. Procacci, Chief Executive Officer of Procacci Development Corporation in Baca Raton, FL.

About Procacci Development Corporation

Procacci Development Corporation is a full-service development, construction and management company with extensive knowledge and experience in commercial office space. Our Company has a defined mission that concentrates on achieving a superior experience for our tenants. We are dedicated to providing real estate solutions that will have a positive impact on our clients’ operations by delivering quality results that exceed the highest industry standards.

Since 1976, we have been creating innovative projects, building quality properties and managing for long-term success. By concentrating on responsiveness, flexibility, persistence and accountability, the Procacci Team has built a solid track record of sustaining tenant satisfaction.

A Little Planning Equals Big Savings: Hardening the Building Exterior Improves Insurability

Hurricane season is a reminder about the importance of planning when constructing a building.  Storm hardening, or building-in protection against high-wind damage, has become an increasing priority for many owners of commercial buildings, developers and project teams.

But before building in a high-risk area, a first step should include hiring a team who understands the importance of storm hardening by utilizing proper building codes and storm protection upgrades, which can save owners large expenses on the back end and increase their likelihood of having an insurable property.

Our team of building consultants has studied what works and what doesn’t in hurricane protection for the past two decades.  GCI can pinpoint what needs to be done from windows, doors and wall systems to roofing and waterproofing.  This is of special significance when insuring the building.

Obtaining insurance for commercial property in coastal areas is getting increasingly more difficult and expensive, but not if a building is properly protected.  We’ve worked with Zurich, a leading property and casualty insurance provider globally and in North America on many projects, including the BB&T building (see story in this issue).  Zurich has created a highly protected risk (HPR) wind standard, which serves as a blueprint to help customers mitigate losses due to hurricanes and windstorms.  Zurich’s HPR wind standards consider the location, design, construction, and protection measures of buildings. They look at factors such as how well building “envelope” integrity can be maintained during hurricanes, the likelihood that water won’t enter the building  (due to wind-driven rain, rain accumulation, flood, or storm surges) and measures that avoid potentially catastrophic foundation damage.

Some key criteria in their guide includes the use of the large-missile impact glazing for high wind coastal locations; reinforced or poured in place concrete walls to endure winds and flying debris and roofs designed to withstand uplift from high winds. Air conditioner units and other equipment on a roof must also be strapped down with steel wire cables or other building code approved securing techniques.

“If a building does not meet high performance criteria like Zurich’s, an owner may be stuck with expensive coverage from companies like Lloyds of London,” says Paul Beers, CEO and managing member of GCI Consultants. “These policies have extremely high deductibles and offer insufficient coverage.  The investment to improve a building or build it right in the first place could pay off significantly in reduced insurance premiums, not to mention business interruption and repair costs if your building is hit by a severe storm.”

Whether new construction or renovation, we can help building owners and developers achieve HPR or similar types of credentials.  Insurers want to meet current or exceed building codes, especially with regard to wind-loading standards.  “It is a good practice to keep detailed records of improvements to receive appropriate insurance credits,” notes Beers.

“Without the proper documentation, it would be difficult to evaluate certain properties,” says Dale Seemans, senior engineering consultant at Zurich. “GCI brings value to us in many ways.  They can help us do ‘forensics’ on a building to assess whether glazing and other systems will stand up to a hurricane.  They literally have dismantled windows from buildings to determine the original manufacturer.  They also routinely recommend glazing systems that lower energy costs and reduce noise.”  GCI and Zurich have collaborated on more than 15 projects in Florida and the Caribbean.

“As a result of good planning and proper documentation, the building owner or developer may be able to obtain better insurance coverage with lower deductibles,” says Seemans.  “As a benefit to tenants, an intact building envelope will allow them to get back to business immediately following a storm.”

With improved product technology, regular field-testing, and a team of experts working together, even a multi-storied, glass façade building set near the coastline in a hurricane-prone region can achieve lower insurance premiums. The how is in the planning — whether it’s new construction or a renovation.

Building Commissioning and the Envelope

Building Commissioning is a quality-oriented process for achieving, verifying, and documenting that the performance of facilities, systems, and assemblies meet defined objectives and criteria.  It begins at project inception and continues through the life of the facility.  The process of commissioning, as defined by ASHRAE Guideline 0-2005 The Commissioning Process, can be applied to any system, new or existing.

In order to understand how commissioning can be applied to the building envelope, you must first understand the overall Commissioning Process.  There are four commissioning phases to a project: Pre-Design, Design, Construction, and Occupancy and Operations, with each phase having specific commissioning tasks that should be completed.  The commissioning authority should be on board at project pre-design in order for the owner’s project requirements to be developed and used to guide the remaining scope of work.

The major components of the commissioning process include: developing the owner’s project requirements(OPR), developing the commissioning plan(CP), creating the basis of design(BOD), reviewing plans, specifications and submittal documents, conducting pre-installation meetings and site inspections, conducting testing of systems, developing systems manuals, conducting training for staff, and finally verifying that all systems are working properly and meeting the owner’s project requirements.  It should be noted that the OPR and CP should be developed in the pre-design phase and updated throughout the course of the project.

Commissioning of the building envelope is often overlooked when it comes to this process. After all, most LEED-New Construction(NC) only requires that the HVAC, lighting, domestic water and renewable energy be commissioned in order for a project to be certified.  However, according to LEED-NC 2012 drafts, building envelope commissioning is now being taken into consideration.  The systems listed above will still be a prerequisite, but the building enclosure must be included and reviewed in the OPR and BOD.  In addition, points will be awarded as an option under the enhanced commissioning credit if full envelope commissioning is addressed in accordance with ASHRAE Guideline 0-2005, and NIBS Guideline 3-2006, Exterior Enclosure Technical Requirements for the Commissioning Process.

Although LEED Existing Buildings(EB) does not require building commissioning for a project to be certified, points are awarded if the lighting, process loads, HVAC & R, domestic water heating and renewable energy are commissioned.  There is no specific mention of building envelope commissioning, however the process can still be applied.

Evaluate the current performance of the building envelope by reviewing
prior design and submittal documents, and conducting investigative
site visits. Perform testing on the building envelope which may
include scanning the envelope with a thermal imager and performing
water and air infiltration testing.  Then, evaluate the results and
determine if the envelope is performing up to the standards and owners
requirements.  If it is not, implement solutions by developing
improvement plans.  Finally, verify that improvement goals have been
achieved by using the methods previously mentioned.

NIBS Guideline 3-2006 should be used in conjunction with ASHRAE Guideline 0-2005.  The NIBS guideline focuses on applying the commissioning processes described above to the building envelope.  It addresses performance objectives for the exterior enclosure including the control of heat flow, air flow, noise, fire, light, infrared, ultraviolet, rain penetration, moisture, structural performance, durability, security, reliability, aesthetics, value, constructability, maintainability, and sustainability, however commissioning objective requirements will vary tremendously by type of owner, type and size of building and project objectives.

In summary, the commissioning process is an excellent tool in ensuring that a project is meeting the owner’s requirements and buildings are performing up to energy standards and codes.  Although envelope commissioning may be new to some, it is important to include in your commissioning plan.  “The building envelope plays a crucial role in the performance of any building.  A failed building envelope will not only create persistent operational problems from leaks and drafts, other building systems cannot perform as intended. ” (Commissioning the Windows: Design Phase Strategies for High Performance Buildings)

Top 10 reasons you should include the building envelope in your commissioning plan

• Financial Savings – Energy costs will be reduced by ensuring that the envelope is sealed properly and commissioned systems are coordinated.  “Operating costs of commissioned buildings are reported at 8-20% lower than those of a comparable non-commissioned building.” (General Service Administration, Building Commissioning)
• Achieve LEED Points and Certification – Meet LEED certification needs by adding envelope commissioning prerequisites and recommendations.
• Assure the Owner’s Project Requirements are met – Checklists are developed at project inception to track and coordinate progress, making the commissioning process as seamless as possible.  This ensures all of the owners requirements are accounted for and followed throughout the life of the project.
• Assure there are proper design documents – There can be design errors related to weather barriers, air barriers, vapor barriers, glazing assemblies, and roofs.  Design and specification documents should be reviewed throughout the project.
• Prevent water and air intrusion, mold, mildew, and poor indoor air quality – If there is a moisture problem, it will be from the building envelope.  Envelope assemblies should be field tested and verified to ensure proper installation.
• Installation quality control – All components of the envelope systems should be properly documented and regular site visits should be conducted to ensure proper installation.
• Integrate facility systems and coordination among disciplines – In order for the HVAC system to work properly, the envelope must also be performing up to its requirements.  Coordination among building systems is crucial in order for the Commissioning Plan Objectives to be achieved.
• Proper training of building staff – Verifying that building operators are familiar with the building envelope is important to long-term performance. They should be trained as to the maintenance requirements of the envelope systems and have the ability to identify components that may not be performing to requirements.
• Enhanced Environmental Credentials – Building envelope commissioning is a valuable selling point and will be above the rest in a competitive marketplace.
• Occupant/Tenant Comfort – A building with properly functioning envelope and HVAC systems provides occupants with a comfortable and healthy work environment in all weather conditions.  This is the building owner’s ultimate goal – a building full of satisfied tenants.

Shauna Sproul has a Bachelor’s Degree in Civil Engineering with 3 years of building envelope experience with Glazing Consultants.  Shauna has provided forensic  investigations, analysis and report compilation as it relates to hurricane damage.  Ms. Sproul also holds a Certified Building Commissioning Professional title from the Association of Energy Engineers as well as a LEED Green Associate certificate from the United States Green Building Council.  Shauna can be reached at ssproul@glazingconsultants.com

Case Study – Campus USA

More about your FREE case study…

Glazing Consultants International, LLC,  employs specialist consultants for each building envelope subcategory. Our glazing, exterior wall systems, waterproofing and roof experts provide a specialized expertise that is second to none.

GCI was retained to provide new construction quality control consulting services at the Campus USA Credit Union Headquarters in Gainesville, Florida. The building is 95,000 square feet, three stories high, with an open atrium, skylight above and curtain wall assemblies around the perimeter. The project was completed in 2010.

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Why Hire a Building Envelope Consultant?

I’ve been getting that question from prospective clients a bit lately, and I generally try to answer it in a short and simple way.

I simply state what is vox populi:  water intrusion is the most common and yet the most destructive issue for the structural integrity of a building.  Thus, hiring a qualified building envelope consultant offers a reasonable assurance against problems and pitfalls developing before, during or after construction.

This powerful statement is sometimes enough to secure an assignment.  However, perhaps due to today’s tough economic environment, more often than not, a more elaborate answer is required to convince prospective clients that hiring a building envelope consultant is worth their investment.  When I’m in that scenario, I begin by explaining the basics, and then continue by describing specific services.
So, what are the “basics?”  Simply put, a building envelope consultant focuses on solving or preventing performance problems associated with the enclosures of buildings. The building envelope includes:

• exterior glass curtain walls and storefronts
• windows and doors
• wall systems
• roofs and skylights
• balconies
• and at-grade and below-grade slabs, foundations and basements.

The role of the consultant is to collaborate with owners, designers and builders of construction projects to create high performance building envelope systems.  For existing buildings, we perform investigations of envelope performance problems, which often lead to remedial design and/or management of replacement or rehabilitation programs.

And, what are the “specifics?”

1. On construction projects, the consultant can offer design assistance to architects, developers/owners and general contractors; from design development through construction documents; for all building envelope systems and details.
2. The building envelope consultant provides reviews of plans and specifications, shop drawings and submittals to identify potential problems and recommend solutions before installation.
3. We also conduct pre-installation meetings and perform quality control inspections and testing of materials and products during construction.
4. Similarly, on existing projects the building envelope consultant can investigate and identify envelope performance problems, develop repair scopes including plans and specifications, obtain bids, oversee repairs and provide construction management services.
5. As an independent, third-party inspector of the construction phase for both new and existing projects, the consultant ensures that all building envelope systems are properly installed in accordance with design and submittal documents, code requirements, manufacturers’ specifications and industry standards.

So, what’s the bottom-line? A qualified building envelope consultant brings to the table his or her specialized knowledge, experience and understanding of the latest advances in building envelope technologies, as well as proper design and construction practices as related to the envelope systems.  These are valuable assets for any project team, and can result in great savings related to building performance throughout the life of the structure.  We are often told that these cost savings and the building owner’s added peace of mind more than offset the cost of hiring a consultant on the front end of the project.

Alfonso Alzamora has been a consultant at GCI since 2005. He is a Florida registered Civil Engineer with 10 years of experience in building envelope systems. As a consultant at GCI, Mr. Alzamora has provided design assistance and specification development, architectural review and analysis of product applications, contract administration, field inspections and testing, forensic investigation and analysis, and associated services related to new or existing installations of commercial glazing systems (glass curtain walls, skylights, window and doors), Exterior Insulation and Finish Systems (EIFS) and other exterior wall cladding systems, as well as all aspects of waterproofing these and related products. Mr. Alzamora is also involved in business development and generation of proposals for contractors, engineers, architects, municipalities, attorneys, developers and owners.  Alfonso can be reached at aalzamora@glazingconsultants.com

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Wall Sheathing – It’s what’s inside the wall that counts

By Paul E. Beers

With the popularity of lightweight wall construction using studs and sheathing, water intrusion due to poor design or construction errors is inevitable. One of the most critical decisions with wall system design is what type of wall sheathing to use.  I have investigated hundreds of water intrusion failures with stucco, EIFS or brick veneer cladding and the degree of damage can vary widely depending upon the wall sheathing used.

This article will consider three wall sheathing types – wood (plywood or OSB), paper faced gypsum sheathing and fiberglass faced gypsum sheathing.  Wood sheathing is primarily found in residential construction and gypsum sheathing is used predominately in commercial structures.

Oriented strand board (OSB) sheathing and exterior grade paper faced gypsum sheathing are typically treated to resist some wetting during construction.  Fiberglass faced sheathing by design also resists some wetting during construction.  All three sheathing types are recommended to be protected with a moisture barrier or water resistant air barrier as part of wall system design.  The theory is that any water that infiltrates exterior cladding, joints, wall penetration or windows and doors is shed away from the sheathing and drained back to the outs ide.  In effect, the intent is that the sheathing never gets wet.

The reality is that the moisture barrier must be perfectly designed and constructed to prevent any water from contacting the sheathing.  Another reality is that this often does not happen.  Any design concept that relies on perfection, particularly in construction, is likely to result in eventual failure.

When OSB sheathing, plywood and paper faced gypsum sheathing are subjected to water leakage inside a wall cavity, they become saturated and deteriorate.  This causes them to lose their ability to support the cladding and can also lead to mold and other environmental problems.  Most failures of these systems during severe wind storms reveal degradation of the sheathing due to water intrusion.  Figures 1 – 4  below illustrate water damaged sheathing at a small commercial building type with similar wall construction design except for the sheathing:

Figure 1. – Water damaged OSB Sheathing

Figure 2. – OSG Sheathing rotted away

Figure 3. – Water Damaged Plywood Sheathing

Figure 4. – Water Damaged Gypsum Sheathing

In contrast, fiberglass faced gypsum sheathing is better able to withstand prolonged water intrusion within a wall cavity.  Fiberglass faced gypsum sheathing manufacturers recommend that all board joints and fastener penetrations be sealed prior to the application of cladding.  However, even if this is not done, the performance of this sheathing material when subjected to prolonged water leakage is far superior to the others.  Figure 5 below is from the same group of projects as Figures 1 – 4 above but used fiberglass faced gypsum sheathing.  Note how much less damage there is to the sheathing.

Figure 5 – Fiberglass Faced Gypsum Sheathing

I have investigated many projects with water intrusion into the wall cavity that used fiberglass faced gypsum sheathing and the damage is much less that with other types of sheathing.  Fiberglass faced gypsum sheathing is more expensive that paper faced sheathing, although it is not enough to discourage its use.  Based upon our field experience, GCI always recommends fiberglass faced gypsum sheathing for use as an exterior sheathing.  It still needs an air and water moisture barrier over it inside the wall cavity, but if leakage does occur, the damage and subsequent repairs are greatly reduced.

Paul Beers is the Managing Member of Glazing Consultants International, LLC (GCI), a building envelope consulting firm in business since 1988. He has over 25 years experience in the window and glazing trade and with building envelopes. He is a leading expert with glazing systems and hurricane damage and protection and was instrumental in the development and implementation of missile impact tests after Hurricane Andrew hit Dade County, FL. His expertise includes windows, doors, glass and wall claddings with an emphasis on water leakage and damage. He has served as an expert witness in federal and circuit courts for windows, doors, glass and wall systems and water leakage. Paul can be reached at pbeers@glazingconsultants.com.

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