The first step will generally assess the structure and review any existing analysis from the original design team or other experts. This includes revisiting design and engineering documents, reports, and original drawings to find issues that contributed to the failure. As work gets underway, our teams assess the damaged portions of the façade to determine if they can be repaired or replaced–or if the entire cladding system needs to be reskinned.

Next is determining if a repair is possible on a technical level. Some stone or porcelain veneers, for example, are so thin they cannot be effectively patched and must be replaced entirely. Even if a repair is possible, the logistics may be impractical once you consider the cost of storing panels nearby or moving them off-site during the repair. This may also leave portions of the building exposed to the elements, susceptible to erosion and degradation.

Even if a repair is possible, the logistics may be impractical once you consider the cost of storing panels nearby or moving them off-site during the repair. This may also leave portions of the building exposed to the elements, susceptible to erosion and degradation. In other situations, the original cladding material may be unsuitable for the climate or the structural needs of the building, making a complete reskin necessary.

Another consideration beyond the cladding itself is the framing and anchoring of the panels to the building. New materials may mean different weights and shapes, which may call for altering or fully replacing the existing framing and/or anchoring. These framing members and anchorage also depend on the support wall’s type and strength.

Failure to consider these interrelated systems can lead to quick fixes and temporary solutions, which are more likely to fail again. Choosing the ideal type of framing will depend on the weight and shape of the cladding materials and, ultimately, how these are fastened and supported. More and more EDG has seen projects that rely on thinner stone or porcelain panels laminated on top of a honeycomb backup. This can be a successful and cost-effective design for lower-level buildings and single-floor storefronts. Still, we have seen several cases where this design is prone to failure when used as façade cladding in taller buildings.

When you move from a veneer/ honeycomb system to full-depth stone panels, you increase the weight of the cladding significantly. Moving a project forward safely involves probing to check the integrity of the new framing and new anchorage, and examining the backup wall and superstructure to understand existing conditions and how much weight the building will bear.

We have a broad portfolio at EDG, and many of our projects have historic or landmark designations. We understand the importance of maintaining a building’s unique character, even for buildings without designations. This adherence to original aesthetics means we often work with stone. When ownership is passionate about matching the original look, that means sourcing the exact stone again. There are cases, however, where the original design failed due to the material itself or if it is no longer available. These situations call for choosing a new material with different characteristics that mimic the original look.

We begin the search by poring through EDG’s library of materials and catalogs from our suppliers. We focus on compressive strength, which is the stone’s ability to withstand pressure. We also look at porosity, as more porous stone lets in more water. When this water absorbs into the stone, it can freeze, causing damage. When it comes to matching the aesthetic of the original building, our standard at EDG considers a variety of factors.

The most obvious is color —finding a stone that matches the shade and tone. Our team will examine and consider many samples with similar mineral content, looking for options that best match the original stone. Beyond color, there are unique stone characteristics. Some are unsightly blemishes to avoid, like ferrous inclusions, while others, such as fossil imprints, can be interesting elements worth highlighting. The quality of the quarry is just as important as the stone. When it comes to matching materials, finishing is a major consideration. Some finishes, like a honed style, are simple, but other more advanced finishes can be difficult to replicate consistently.

We travel to great lengths to match materials. One recent project had our team travel to Solancis’ quarries in Portugal to finalize a lengthy hunt for the perfect stone.

“When choosing a quarry and supplier, you want to ensure they are regularly testing the stone,” said Rebecca Reilly, P.E. Senior Restoration Engineer with EDG. “Compared to a factory-produced façade product that yields consistent results, natural stone can vary widely. Regular testing can ensure that all stones received are within an acceptable margin of initial specifications.”

The Portuguese limestone we chose was a good color match and included seashell inclusions similar to the original material. During our visit to Lisbon, EDG team members saw many local examples of this stone in use. All of them were hundreds of years old and in good repair, which speaks well of the longevity of the material.

We liked the care we saw in every stage of the process, from quarrying the stone with heavy machinery to moving it to a factory for finishing. The stone was scanned by a machine that identified imperfections and also visually inspected by an expert. This dual process makes it easier to spot problems, work around them, or swap pieces of stone around in a game of high-tech Tetris. Once the stone was scanned, inspected and cut, computer-operated machinery applied finishing. This machine-level precision ensured a consistent look across each panel and a streamlined look for the building. Because Solancis can cut and finish the panels on-site, they can ship directly to the contractor with less logistical fuss. Their care in packing and shipping orders (many of them overseas) is one of the primary reasons we work with them.

Sometimes, when a façade fails, it’s not just about the material but about the system as a whole. When it comes to waterproofing, both open and closed joint systems can work — but intermingling the two can create problems.

When a waterproofing system is not working properly, excess water can build up and erode materials. At EDG, we have seen issues arise when other designers close the joints but do not create pathways for water to escape. Other times, the waterproofing material itself was a poor choice for the building. For example, sheet and liquid applied waterproofing can create air pockets or fail to adhere properly when the styles are intermingled. This can be especially true around windows. Waterproofing is one example of an interrelated system you have to consider when replacing or repairing a façade. A reskin is likely to leave some areas of the building exposed to direct sunlight for months at a time. Even if the original waterproofing system is working as intended, it may not be rated for long-term UV exposure.

Our experts at EDG faced this exact problem on a failing façade we consulted on, and ultimately, we chose a UV-stable waterproofing system to replace the damaged one. Elastoflex from RD coatings is fluid-applied, so it is a liquid with reinforcement and rated for continuous sunlight exposure. The flexibility of a fluid-applied system is helpful, especially when dealing with façade penetrations like existing windows and doors. After new waterproofing is applied, it is critical to ensure the specifications match the rest of the anchoring and cladding. Considering whether the drainage system is an open or closed joint design, if and how many weep holes should be present, and other ways to safely move water off the stone and into the drainage system are all important to this process.