In March, significant progress was made in the World Heritage Preserved campaign at Fallingwater. A major milestone was the completion of the grout injection project, which concluded after several months of intensive work. Crews from Masonry Solutions International injected nearly 12 tons of grout—approximately 1,740 gallons—into the house’s hollow walls to help mitigate water infiltration issues. For more in-depth information on the grout injection process, please see the December 2024 update.

Preservation also advanced on Liliane’s Terrace, where deteriorating concrete walls were skillfully demolished and rebuilt. Large sections of compromised concrete were removed, exposing the steel reinforcement within. The steel was then cleaned and coated to protect against corrosion. Afterward, new concrete was poured into plywood molds, followed by the hand-applied parge coat—a cement layer designed to replicate the original finish—before the walls were repainted.

Preservation crews are nearing the completion of some of the most intensive restoration work that occurred this winter at the house. We’re now in the process of dismantling the scaffolding and enclosures in the west and south facades of Fallingwater—most notably the large tower above the waterfall, prominently visible from the Iconic View. You can watch along on our YouTube channel and the Fallingwater Live Cam, as we transition from our Preservation-in-Action tours to our Guided Architectural tours.

February was a significant month for preservation efforts at Fallingwater. As noted in our January and December blog posts, much of Fallingwater remains surrounded by scaffolding and protective enclosures. Inside these spaces, a variety of specialized contractors are working, assisted by our own dedicated preservation and maintenance team. Continued work on the west living room terrace, steel conservation on our window frames, grout injection into the voids within our stone walls, and repairs to degraded concrete were among the project this month. Much of the work was similar to that undertaking last winter.

Before crews could install new waterproofing membranes and flashings on the west terrace, Fallingwater’s preservation maintenance team first prepared the area by constructing plywood enclosures, insulating and heating them to ensure a warm and dry workspace. Next, each piece of the flagstone surface was numbered and removed before the existing water membranes underneath them were removed. Once the terrace was prepped for Allegheny Roofing’s crew to begin work, the old waterproofing and plywood subfloor beneath the stone was removed with new plywood installed, followed by two layers of cold-applied waterproofing membrane. Once the membrane was in place, a liquid flashing material was applied to all corners, drains and vents for added water-repellent protection. As with the east terrace, the drains will be refashioned to improve the movement of water beneath the flagstone. The finishing touch, expected in March, will be for our team to relay the stone and apply mortar into the joints.

In addition to the West Terrace waterproofing, steel conservation work occurred, focused on the double bifold glass doors leading from the Living Room to the West Terrace. Our window conservators, H.P. Steel Window Restoration, secured and stabilized the door track supporting the bifold doors. The conservation of a further selection of window frames also kept our contractor busy, with a full glass replacement of all doors in the house slated for later in 2025.

During the tour off-season, one area of focus for Fallingwater’s preservation team has been the reinforcement of the Canopied Walkway. This Wright-designed walkway, which connects the Main House to the Guest House, has also faced deterioration of its concrete over time.

Although the majority of the Canopied Walkway is in good condition, the stone pier that supports the lower part of the canopy required significant repairs. Constructed of reinforced concrete, this element of Wright’s design is only four inches thick, and cracks have caused the steel reinforcing bars to become exposed to the elements. This exposure has allowed water to wick into the concrete, leading to the expansion and corrosion of the steel, which, when untreated, could potentially cause structural damage.

To mitigate this, our preservation team implemented a fiber-reinforced cement matrix (FRCM) as an intervention, strengthening the concrete through an application of a fabric-like fiber polymer mesh. The process began with removing the deteriorated material and hand applying new concrete onto which the FRCM mesh was applied to further reinforce the canopy structure.

In addition to the work on the Canopied Walkway, the preservation team continued its significant progress on waterproofing membrane replacement atop the Servant’s Quarters. This process followed a similar approach to our recent roofing project on the lower guest house roof, which has been detailed in previous blog updates (see June and July 2024 blog entries below). This work at the Servant’s Quarters concluded last week.

As you may have noticed on the Fallingwater Live Cam, scaffolding now envelopes much of Fallingwater’s south and west facades. This preservation work is expected to be completed by the end of March. We plan to have the scaffolding removed as soon as we can, but the scale of the preservation work demands meticulous attention to detail and some flexibility in the scheduling. Stay tuned to our social media platforms and this blog for updates. And, don’t forget to schedule a Preservation-in-Action Tour to see this work in action!

Fallingwater Tours

As you may already know, Fallingwater’s preservation crew was busy building scaffolding at the Main House at Fallingwater in early December in preparation for the largest leg of our World Heritage Preserved efforts. Starting December 1, 2024, crews from BrandSafway Industries of Pittsburgh began erecting scaffolding at the base of the waterfall that extends upward to enclose the house’s chimney mass– covering nearly the entire south and west elevations of Fallingwater. The scaffolding, which took nearly three weeks to complete, creates a safe, level area for the preservations crews to waterproof and reroof much of the Main House.

Fallingwater’s maintenance crew has also utilized the scaffolding and begun turning the structure into a climate-controlled environment by attaching sheets of insulation board and draping plastic sheeting to keep the elements at bay for workers while also creating a means to contain construction debris and dust.

For fans of the Fallingwater live stream (also known as the Fallingwater Cam), you’ll be able to watch as final preparations are made on this enclosure. Soon, Fallingwater will be shrouded behind the scaffolding and climate-controlled barriers.

The scaffolding and enclosures will impact your view of the house’s exterior through the end of March 2025. You can experience this work and preservation in person via a Winter Walk or during special preservation tours starting in March.

Fallingwater Tours – Fallingwater

Stay tuned for next month’s blog post on the roofing and masonry repairs in the Main House.

November has been busy with preservation efforts here at Fallingwater. We have finalized the work on the Guest House roof and fully dismantled the scaffolding which has surrounded the building for the past few months.

New scaffolding was erected along the north wall of Fallingwater, just outside of Edgar Kaufmann Sr.’s Study to allow for grout injection to begin. The process involves drilling grids of portholes in the mortar joints on the exterior stone wall to allow for grout to be injected. As the grout is pumped into the stone masonry walls, it flows into existing voids, fills them up, and eventually hardens. These voids have long been problematic for the house, allowing water to travel from the outside into interior spaces. By filling all these voids with grout, water will no longer have pathways to flow inside.  

While the contractors are drilling and injecting the grout on the exterior of the wall, contractors on the interior are watching for water and grout leaks.

In addition to the grout injection, our preservation crews are also working on the Servants’ Quarters roof. The process will be the same that the Guest House underwent – see the July 2024 blog for a detailed overview of that process. A large scaffolding enclosure was erected over the Servants’ Quarters in order to provide a warm weatherproof area necessary to complete the roofing work. Preservation efforts at the Servants’ Quarters are scheduled to wrap in late December.

Listen to Pamela Jerome, president of Architectural Preservation Studio, DPC in New York City, explain her many roles at Fallingwater over the past few decades. As the principal architect in charge of restoration at Fallingwater, co-author of our preservation masterplan and 10 years as project manager, Pamela has seen Fallingwater inside and out more than almost anyone else. In this video, Pamela discusses the current and future preservation work planned for 2025 and 2026. You can find our full preservation announcement here about work happening now through the end of this year.

The Fallingwater preservation team will soon be removing the scaffolding from the Guest House—concluding that phase mid-October—to the Carport. This area serves as the conclusion to our tours and the venue for membership discussions. Although the new scaffolding arrangement is designed to minimally interfere with tours, it may surprise some visitors. While this will have some impact on your tour experience, visitors are encouraged to view this process as part of the necessary and active preservation of Frank Lloyd Wright’s masterwork.

We are also preparing for our most significant project to date for World Heritage Preserved. Scaffolding will soon envelop the southern and eastern sides of the house that overlook the Iconic View. This scaffolding structure will be very large and obstruct two of the most significant viewing angles of Fallingwater. However, the scaffolding will facilitate the necessary space and support for the concrete and window restoration work scheduled for late November. We plan to have the scaffolding removed before we open for the 2025 season.

As we wrapped up the roof work on the Guest House, our preservation crews have, for the first time since Fallingwater was erected, removed a window from a building. This window is located at the back of the Staff Quarters facing the Guest House.  

The window was removed by window conservators from HP Steel Window Restoration of Wappingers Falls, NY, on September 4, 2024, after several days of carefully hand-chiseling away the mortar that has held the frame in place for nearly 90 years. After the window’s removal, it was transported to HP Steel’s workshop to make repairs to the steel in areas where it had degraded or corroded, then apply a fresh coating of paint as well and replace the glass. The window is scheduled to return to Fallingwater the week of September 30, 2024, for reinstallation.

More importantly, the window removal process gave the preservation crew and Fallingwater staff a rare glimpse into how the windows were originally installed during the construction of the Staff Quarters. The removal was fully documented and with this new understanding of Frank Lloyd Wright’s building methods, we can approach future preservation projects with greater insight. This knowledge will help us preserve his vision more effectively while adapting to contemporary needs.

In early July, we used a resurfacing machine to roughen the surface of the concrete on the main Guest House roof. A roughened concrete surface was needed as part of the installation of the new roofing system installation. To minimize noise disturbances to our visitors, the work took place outside of our regular tour hours.

The first step in the new roofing system was to apply an epoxy coat was applied over the entire roof slab. Epoxy is a special roof coating that helps combat moisture by penetrating and filling any cracks and imperfections in the concrete, creating a solid waterproof layer over the roof slab. A torch-applied roofing layer was placed over the epoxy system to protect it. These layers of roof replacement were completed in mid-July.

They also completed other concrete patching on the East Terrace of the Main House, including the rounded parapet wall over the hatch.

We completed several significant projects at the Guest House in June, including the partial demolition and concrete recasting of the Guest House’s east parapet wall. It required repair due to the deteriorated stucco and significantly compromised concrete initially found during a routine inspection. Although slow, meticulous and sometimes hampered by weather, work on the wall is now complete.

Also, the removal of the existing Guest House roof was completed in preparation for the installation of the new roofing system. During demolition, we found that the existing roof insulation board was fully saturated with water, and the concrete below was also holding water, which necessitated significant drying time for the slab before the new roofing material could be applied.

Meanwhile, we installed a mock-up of the new roofing system on the furnace room roof to ensure good application. Confident after monitoring and observations that the application was successful, the team continued preparation for the main Guest House roof replacement.

April showers didn’t bring May flowers, but rather delayed preservation activities at the Guest House and Main House East Terrace and ushered in a reminder of the importance of our comprehensive World Heritage Preserved restoration effort.

As if on cue, the wettest April ever recorded in the region since 1871 was ironically perfect timing for us to test if the various applications of grout injection and masonry improvements worked to avert and prevent water from entering the Guest House and Main House. Although there was success, we learned there is still more work to do.

We were pleased to welcome John Matteo of Matteo Ferran Structural Engineers back on site in late April to further evaluate the Guest House east parapet wall to determine the extent of necessary demolition to repair it. Through various assessments, he helped determine that the first 18 inches of concrete was intact and in normal condition.

However, he noted that in some areas, the stucco had delaminated and water was observed trapped within the layers of stucco and concrete. The deteriorated stucco was removed at one of the locations, and the concrete found behind it was in good condition. Careful demolition of the east parapet wall occurred, though ultimately most of it was removed due to its poor condition. Members of Fallingwater’s maintenance team then worked alongside masons from Graciano to reconstruct the parapet.

Other Guest House masonry repairs included the dismantling of the stone parapet wall above the furnace room roof to reveal the existing slab construction and its waterproofing material transition between the furnace room and Guest House roof slabs. The disassembling confirmed additional waterproofing and moisture issues in these areas, all to be addressed in the coming month.

Mother Nature’s elements were on full display this April in the mountains of Southwestern Pennsylvania when heavy rains from several storm systems caused devastating flooding, high-velocity winds and property damage across the region. Fallingwater wasn’t immune, as water rose above the Plunge Pool wall and above the first two hatch stairs. But thanks to our quick-thinking and hardworking maintenance team, branches, litter and other debris that washed down Bear Run were removed before they could cause any serious damage to the house. 

Even so, moisture found its way inside the house, through the roofs and walls, and caused leaks in several locations, such as over the hatch in the living room caused by a cracked and deteriorated area of the concrete terrace above it. There are locations in the house, including Edgar Sr.’s study, Edgar jr.’s study and Liliane’s terrace, where leaks occur regularly during heavy rain events. Our contractors and maintenance teams conducted visual assessments throughout the house to identify additional water issues, which will add in upcoming repairs to masonry, roofing membranes and flashings in these areas.

On the dryer days, waterproofing repairs continued on the East Terrace. Allegheny Roofing and Sheet Metal contractors installed lead flashing at the masonry walls of the East Terrace. To prepare for applying silicone sealant, our maintenance team repointed the boundaries of the flagstones at the concrete walls and installed grout at the flagstone borders. A direct result of these applications, and other ongoing waterproofing and masonry work, will be to permanently address leaks in walls and ponding occurrences on the roofs and terraces.

As we prepare for Fallingwater’s 61^st tour season, we are pleased with the progress that occurred over the winter months. Waterproofing the East Terrace was completed by Allegheny Roofing and Sheet Metal contractors. Once the contractors finished, our maintenance team carefully replaced the flagstone and filled its mortar joints to return the terrace’s topmost layer back to its original appearance. Because the mortar needs to cure, the terrace will remain closed to the public into April.

We also removed the scaffolding along the driveway and front entrance after dismantling the temporary heating system installed to allow the masons to work comfortably while they completed grout injection, installation of capstone flashing and stone repointing. Our entire maintenance team was needed to efficiently “unwrap” the house for visitors to enjoy the new preservation work on opening day.

This month’s preservation work involved erecting scaffolding and then wrapping it in plastic to create a warm environment for contractors to work. Three scaffolds along the north face of the main house allow for grout injection along the driveway and repointing of the north wall of the main entrance, dining room and kitchen area.

Using the knowledge gained from the Guest House, grout was injected systematically along the pottery terrace roof parapet, while the repointing crew worked near the kitchen door and Edgar Kaufmann Sr.’s terrace. Providing heated temporary enclosed spaces necessitated an additional generator to increase power to keep the masonry at a consistent temperature for efficient (and effective) repointing.

The roofing team finished work on the concrete roof of the bathroom in the Guest House applying pea gravel to finish the waterproofing system there, and continued preparing for a waterproofing membrane on the skylights above the library desk and beneath the flagstones of the East Terrace.

As we begin a new year, contractors and the Fallingwater maintenance team erected temporary enclosures on the East Terrace to keep the work site warm and dry. The maintenance team carefully removed all the flagstones to expose the underlying waterproofing membranes. Then, the roofing team removed the existing membranes in preparation for installation of new materials.

As work progressed on the East Terrace, the roofing team simultaneously worked on the roof of the Guest House in another temporary enclosure. Here, the team applied a new waterproofing membrane to the concrete slab roof of the bathroom, an area Frank Lloyd Wright referred to as the “monitor.”

As we continue preservation, the next area of focus is the East Terrace. Some temporary exterior changes to Fallingwater have occurred in conjunction with our ongoing work. Before the roofers can install new waterproofing membranes and flashings to the terrace, our Fallingwater maintenance crew prepared the area.

First, our team erected a temporary enclosure to keep the work area warm and dry. Then, they removed the flagstone and underlying bedding of sand to expose the existing waterproofing membranes below.  Once the terrace is prepared, the roofers will remove the existing membranes and replace them with new ones to make the terrace watertight.

Although access to the East Terrace will be closed while this work is completed, visitors on tours through December can observe this preservation work in progress.

Due to cold weather during November, extra steps were necessary to keep Fallingwater’s preservation projects on track. One added step was creating an enclosure for the roofers. This kept conditions warm enough to apply a waterproofing membrane onto the raised roof of the Guest House bathroom, which Frank Lloyd Wright always referred to as “The Monitor” in all correspondences.

We also constructed an enclosure over the main stone masonry wall of the Guest House. In addition to this enclosure, the masonry team draped blankets over the stone to keep the work area warm. If the mortar gets too cold it won’t adhere to the stone as it dried. With the grout injection completed at the Guest House, a five-man team finished work in this area by repointing the walls.

October was another busy month for the Masonry Solutions International team. They worked to meticulously inject grout into the voids, left during the original construction, of Guest House walls. The method used prevents the development of air pockets. Injecting the walls with grout will improve overall wall stability and integrity, and decrease the ability for water to enter the house from the roof.

The team used water to wash away extra grout material in an effort to prevent staining of the exterior stone wall surfaces. This clean-up method also ensured a finished appearance to the walls.

In this short video, Scott Perkins, Fallingwater’s senior director of preservation and collections, provides an update on some of the preservation work that occurred during September on the Guest House roof. Learn about work to replace portions of the concrete roof and see some of the new products and materials being tested to prevent water from entering the Guest House from underneath the capstones.

You’ll also see one of the voids at the top of a Guest House wall, where grout will be injected to fill the space in an effort to prevent further water damage.

Learn more in this two-minute behind-the-scenes glimpse by clicking the video play button to the left.

Thanks to the generosity of many private donors, foundations and Commonwealth of Pennsylvania funding, work is advancing on Fallingwater’s major building systems that need urgent attention.

In this short video, Fallingwater Senior Director of Preservation and Collections Scott Perkins gives a brief update on some recent work at the Guest House to replace the waterproofing membranes on the roofs and terraces, repoint and grout stonework to prevent water leaks and repair degraded concrete. This important work is being accomplished by preservation contractors and professionals. Stay tuned for more updates from Scott and others as work progresses!

To watch this two-minute video, click below.

Involved with Fallingwater’s preservation since 1988, Pamela Jerome is the lead architect overseeing the preservation work associated with Fallingwater’s World Heritage Preserved Campaign. As the president of Architectural Preservation Studio, DPC, a New York City-based architecture and preservation firm, Pamela is recognized as an international expert in cultural heritage with a specialization in masonry conservation and waterproofing.

Pamela’s team produced the 2019 Fallingwater Preservation master plan incorporating new research, investigations, prototype repairs and the execution of an existing conditions assessment, all to update the previous 1999 master plan which Pamela helped create more than 20 years ago. The current three-year phased plan is underway and scheduled to be completed in late 2025.

Pamela says her past Fallingwater experience was rewarding and informative, and will be vital to the success of the current preservation work. “For Fallingwater, we have designed discreet interventions that improve the functioning of the exterior envelope. We also have the benefit of knowing what worked and what did not. I was the project manager for the first holistic restoration from 1999-2002, so I personally have a lot of institutional knowledge and insight about the technical issues that face Fallingwater.”

Pamela is assisted by APS Studio Manager Stephanie Gerard and APS Architectural Preservationist Vishal Joshi. Combined, these three architects bring more than 60 years of expertise to our project.

In addition to Fallingwater, Pamela and her studio have preserved some of the most important buildings of the 20th century, including Frank Lloyd Wright’s Solomon R. Guggenheim Museum, the historic Breakers and Château-sur-Mer mansions in Newport, Rhode Island, and Louis Sullivan’s Bayard-Condict building in New York City.

Graciano, a Pittsburgh-based masonry firm, completed the mortar repointing in April which allowed for the next task in the Guest House project work: testing specified grout injection materials and methods for the Guest House stone walls.

Structural engineers from Atkinson-Noland Associates drilled small holes and inserted borescopes (thin, flexible, tube-like cameras) into the stone wall cavities to capture video and photography to monitor various conditions and moisture levels.

This visual monitoring and information helped Masonry Solutions International determine the preferred process and locations of where to strategically inject grout into the wall cavities. The work occurred during the evenings and on a Wednesday in May to lessen the impact to Fallingwater visitors.

Graciano, a Pittsburgh-based masonry firm, completed a small masonry repointing project on the northeast corner pier of the Guest House on April 25 and 26 to prepare the pier for a mock-up test of the grout injection process. This test addresses water infiltration concerns by inhibiting the movement of water within the voids of Fallingwater’s stone walls. The work also included matching existing mortar in both color and composition.

The test will provide insights into how to successfully use the process in upcoming preservation projects. Pamela Jerome, our preservation architect, and John Matteo, our structural engineer, specified the grout injection process to address the effects of water infiltration.

“Fallingwater’s original materials are conserved and preserved whenever possible,” says Fallingwater Senior Director of Preservation and Collections Scott Perkins. “Yet we also need to consider newer techniques and methods to demonstrate to our visitors and members the excellent stewardship methods we are undertaking.”

H. P. Steel Window Restoration completed conservation work on the original Hope’s windows in the Guest House. The team began repairing areas of corroded steel on the clerestory window frames from March 16-23. They primed and painted the frames with coating products manufactured by Tnemec (“cement” spelled backward).

The glass panes of two clerestory windows on the north elevation of the Guest House are embedded into mortar-filled channels in the stonework and needed to be replaced because of separation or cracking along the surface.

Finally, Advanced Caulking Services sealed the replacement glass using a thin bead of silicone to minimize the potential for future cracking. The color-matched silicone honors the original intent of Frank Lloyd Wright while allowing the glass to float within channels to better react to weather changes.

One of the first activities to prepare for the preservation work on Fallingwater’s major building systems was the temporary removal of built-in casework, desks and wall shelving in the Guest House bedroom, Edgar jr.’s Study and Edgar Sr.’s Dressing Room and Study. This work was completed throughout February by our wood conservators to expose the stone walls for mortar work.

Fallingwater’s maintenance team repaired hairline cracks in the mortar joints of the stone walls of the main chimney and established various test sites within the Guest House. Using a process called repointing, the team removed portions of the deteriorated mortar using hand chiseling tools and added new mortar to the joints to repair the cracks. Filling these cracks prepares the walls for a future grout injection.

This extensive repointing process also helps seal the walls from within to help prevent further water infiltration. After the repointing was completed, the built-in furnishings were set back into place by the conservation team. To prepare for the season’s March 11 opening date, Fallingwater’s housekeeping team cleaned and reset each room with its furniture, artwork, books and decorative objects.