Keys to Ensuring a Sensible Recladding Project

02/27/2017 | By Justin Feit

Rational preservation of exteriors prevents costly catastrophes

When your building exhibits signs of severe cladding degradation and widespread leakage impacting the interior, it might be time to consider recladding. But this process can lead to critical mistakes along the way that impact the integrity of your building. What do you need to do to make sure your building is properly clad?

The Roles of Facility Managers

One major misconception about recladding is that facility managers are to blame for the degradation of the exterior elements of a building. However, it is quite rare for the actions or inactions of an FM to necessitate a recladding project.  

“Facility managers typically take care of buildings after they are built, and many people who are not that familiar with building enclosure systems often blame leakage and other cladding problems on inadequate maintenance,” says Paul Lukes, Owner of PAUL LUKES: Building Envelope Consulting Services LLC in Seattle. “In my experience, this is almost never the case, and essentially all such problems reflect flaws in the original design or installation.”

Lukes adds that this does not mean FMs should neglect maintenance of the exterior elements of a building, as those efforts can boost longevity and appearance, but it can be a difficult battle to win if critical mistakes were made during design and installation.

“If you have a poorly designed or installed cladding system, you might need to maintain it every six months, but beyond that it becomes a heroic effort to try to overcome the poor design,” explains Lukes.

The best thing you can do during a cladding project is to maintain strong oversight throughout the entire process, especially installation.

Selecting Materials for Cladding

The ideal cladding for a building will balance functionality and aesthetics. When selecting the right materials, what might work in one area might result in catastrophic consequences in another. Weather and climate types are critically important during this decision-making process.

For example, stucco is a suitable cladding material in Arizona because it can last more or less indefinitely in its hot and arid climate, according to Paul Lukes, Owner of PAUL LUKES: Building Envelope Consulting Services LLC in Seattle. However, stucco used in a wet and salty location like San Francisco might degrade in 20 to 30 years due to corrosion of its reinforcing lath and metal trims.

“Similarly, while masonry can last essentially indefinitely in relatively warm and moderately moist or dry climates, cold and wet climates can destroy masonry in 6 to 8 decades due to freeze-spalling,” says Lukes.

Every climate has certain characteristics that will render some materials useless. Thus, consult with an envelope professional about what will work best and last the longest in your location.

“I’ve been doing on-site construction inspections for 35 years. I have not yet walked off a site once where everything has been correctly installed,” says Lukes. “One thing I would stress to facility managers or those designing buildings is that it doesn’t matter how well you design them unless you have someone on-site actually overseeing installation.”

Special Recladding Challenges

Despite this focus on proper design and installation, there is often a desire to maintain the building to the exact specifications of its original construction. This often leads to many projects eventually recreating the same problems down the line.

“The misconception is often assuming that the original architect was an all-knowing demigod incapable of making errors,” says Lukes. “Historic preservation boards are typically insistent on preserving the existing materials and methods even when preserving the existing materials is many times as costly and produces vastly lesser results than replacing these with similar, but newer materials.  

“They also typically insist on duplicating the existing design even when that design contains obvious technical flaws the original architect would no doubt want to correct if afforded the opportunity,” Lukes adds.

Lukes has seen firsthand the problems of following the original plans for a building too closely. In one project, a preservation board insisted on patching sandstone, which had become dangerously degraded. This patchwork would have only provided roughly five more years before it would require more work, Lukes explains. Conversely, pre-cast concrete sills could have provided a century of maintenance-free life and can be made to look like the original sandstone.

Decisions like this can be costly, as these solutions are often delaying the inevitable – a more thorough and well-informed reconstruction effort.

Alaska State Capitol Project

The Alaska State Capitol is currently being reclad, and the project prompted debates about historical preservation.

The building, completed in 1931, was designed similarly to its contemporaries, but Juneau’s climate was tough on the masonry, degrading the building’s exterior elements much faster than those in milder conditions. This, in addition to the structure needing significant seismic retrofitting, required the state to improve the building’s cladding.

The design team employed a reconstruction approach as opposed to a strict preservation approach, meaning that the building would undergo improvements and corrections to the original design that allow the building to become vastly safer, more energy-efficient and much more durable.

Further, recladding would yield a lifespan of roughly 100-150 years, compared to the preservation approach, which would at best extend the lifespan by 40 years. Additionally, recladding would cost only marginally more than a strict preservation approach. In providing these improvements to the building, this reconstruction approach maintains the original appearance of the building.

“We very nearly duplicated the original design’s appearance, but corrected some of the original design’s technical flaws and replaced severely degraded masonry with new masonry. We also rebuilt the roof-level cornice, enhancing the building’s appearance and reverting it closer to its original design while at the same time helping to shelter the exterior masonry from weathering damage,” says Lukes. “I think the intent should be to maintain the existing historic building’s appearance to the greatest feasible degree, but to also correct original flaws and improve safety, energy efficiency and performance.”

Public response to the Capitol’s recladding has been positive. Although Lukes’s recommendation to reclad the building met some initial hesitancy and on the surface may have seemed a bit extreme, the considerations favoring it were so compelling the state agreed to reclad the building.

Justin Feit is assistant editor of BUILDINGS.

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