The Challenges of Assessing Structural Brick Veneer Panels

The origin of Structural Brick Veneer Panel dates back to the early sixties when new "tensile strength intensive" exotic mortar combined with steel reinforcing to create a 4-inch thick, single wythe brick panel. Developments continued to occur throughout the 1960s and 1970s, peaking in use during the 1980s. The system was relatively expensive due to the use of the high tensile strength mortar.

Developments in both the high tensile strength mortar and the clay units continued to reduce cost and allow the use of regular reinforcing and standard mortar and grout. Newer systems and manufacturing processes accommodated both horizontal and vertical reinforcing and permitted high-lift grouting. Later advancements in the connections of the brick veneer panel system to the building frame resulted in the use of brick veneer panels system on multi-story high-rise office buildings, schools, apartment buildings, residences and many other applications throughout the United States and the Pacific Northwest.

There are two major failure mechanisms of Structural Brick Veneer Panels: water intrusion and mortar/grout additives.  Water intrusion can occur from a lack of adequate flashing at the window head and sill interface, carbonization of the mortar, and structural cracking. Brick veneer panels are commonly designed to allow for limited cracking at the horizontal bed joints at the brick to mortar interface. Masonry veneer panels leak more through the mortar and brick interface than through the masonry unit itself. If the mortar and brick interface is cracked, as is permitted under structural design calculations, water infiltration will increase. A cement based material, panel mortar will carbonize over time decreasing the protective alkalinity environment surrounding the reinforcing bar and thus increasing the potential for corrosion. The largest volume of water intrusion is typically associated with inadequate window systems that fail to keep water out of both the structural brick veneer panel and the cavity interface.

The durability of the wall is highly influenced by the quality of the mortar joints and interior cell grout. The specification should require re-consolidation of the grout or the incorporation of additives that balance expanding, retarding, and water reducing agents to provide a slow, controlled expansion prior to the grout hardening. Mortar/grout additives, particularly those developed in the 1970s, containing vinylidene chloride can initiate and accelerate reinforcing steel corrosion under the right conditions. The composition of the mortar/grout is determined through laboratory analysis of chloride content, vinylidene chloride, and pH level.

Repairs to structural brick veneer panels is labor intensive and may involve panel replacement, panel encapsulation, window system replacement, and/or extensive individual masonry unit repair.

  Image Acknowledgement: Tawresey, John G. & John M. Hochwalt, KPFF Structural Engineers, Design Guide for Structural Brick Veneer, 3^rd Ed, Western State Clay Products Association

Super-Sized Historic Structures: A Preservation Dilemma

The Blimp Hangar, Naval Air Station Tillamook

Without considerable effort, the Guinness Book of World Records’ largest wooden structure, and the most extant naval air station from World War II is in danger of disappearing. 

Commissioned in 1942 and operational through 1949, the Naval Air Station Tillamook (NAS) is a 1,600 acre site comprised of buildings, structures, landscape features, as well as a current active runway. A smaller 400 acre site has been designated an eligible historic district. The original use by the NAS Tillamook contained 32 defense, eight industrial, five government, four transportation, three commercial, three agricultural, three residential, two recreation and culture, one education, and one utilitarian structures, plus one cemetery. The most significant structures include the airfield, Hangars A & B, ammunition magazines, and structures that supported the operation of the Naval Air Station. Many of the buildings may be the only remaining example of their kind. Much of the site is still operational:  the roads, sidewalks, water power sewer and utility lines, as well as the railroad infrastructure were constructed by the US Navy remain on site and are character defining features.

Hangars A & B were built for “K type” dirigibles that are steerable, non-rigid, lighter than air aircraft used for naval air patrol of enemy submarines. During World War II, the hangars served as mooring and maintenance sites for two squadrons of dirigibles that patrolled the coast line from the Strait of Juan de Fuca to California. A fire in 1992 destroyed Hangar A. The remaining U.S. Naval Air Station Dirigible Hangar B, is the world’s largest wooden clear-span structure measuring ¼ mile long and 23 stories in height. Its construction technique is considered both resourceful for war time efforts and an innovative structural solution. Incredibly, the hangar was
completed in just 90 days.

Hangar B reflects the unique challenges associated with super-sized historic properties. Monumental historic properties pose significant management, maintenance, and financial challenges to the long-term stewardship of such properties. Aging infrastructure, 70 or more years of service-life, and limited lease markets for using enormous structures increasingly place pressures on the decisions to retain the resources. Despite the desire to be good stewards, large properties rarely generate sufficient funding to go beyond very basic emergency and/or minor piece meal repairs. Straight forward maintenance items, like new roofing or painting, can cost several million dollars.

Creative, multi-jurisdictional, community involvement, private/public partnerships, government programs, and national and international marketing campaigns have become key elements to long range cultural resource management plans. The unique structures require innovative solutions matching the monumental character and commanding presence. Success stories abound from the saving of West Baden Springs Hotel in French Lick, Indiana to Centennial Hall in Wroclaw, Poland. The efforts to retain the giant structures are well deserved, because the continued loss of such buildings diminishes our understanding of world events. 

Peter Meijer Architect, PC has been engaged by the Port of Tillamook Bay since 2005 to provide a wide range of preservation related services regarding Naval Air Station Tillamook; Historic photos from the Tillamook County Historical Museum.

Conservation: A Case Study between Art and Architecture

The Oregon State Capitol is a landmark of Modernistic design based on Classical Architecture, and was designed by the New York architectural firm of Trowbridge and Livingston in association with Francis Keally. Completed at the height of the Depression in 1938, the Capitol received funding assistance from the Federal Emergency Administration of Public Works (P.W.A.). Constructed of reinforced concrete, the building is distinguished by angular, unadorned exterior elevations and a massive, ribbed lantern – all sheathed in brilliant white Vermont marble. Artists of national reputation, Ulric Ellerhusen, Leo Friedlander, Barry Faulkner, and Franck Schwarz, collaborated in the winning design and were employed at the recommendation of the architects to produce sculptural relief and paintings of a taut and finely wrought decorative program. Erected in the Modernistic style, the Capitol was sensitively enlarged in 1977 by the Portland firm of Wolff Zimmer Gunsul Frasca in association with Pietro Belluschi.

On Labor Day 2008, a construction fire damaged the exterior Vermont marble, interior Oregon walnut wood panels and a painting by Barry Faulkner adorning the Governor’s Ceremonial Suite. A team of preservation architects and art conservators collaborated to guide the faithful restoration of this important Oregon icon. All restoration work was based on historic research and field analysis of existing materials, but conservation principles were applied differently to the restoration of interior finishes compared to The State of Oregon artwork by Barry Faulkner.

Fire destroyed all the wood panels on the south wall and caused extensive smoke and heat damage on the east and west walls. The north wall suffered minor smoke damage with little to no impact from heat. Oregon Walnut, a species of wood no longer readily available or milled, was incorporated into 30” x 30” veneer panels separated by 1” wide solid walnut splines.  Each panel was book matched resulting in pairs of cathedrals providing strong visual character. It was determined through both field and laboratory testing that the original finish system was a shellac formula readily used during the late 1930s. Conservation strategies had to consider: proper dismantling techniques of the remaining panels; reproduction of original finishes using volatile compounds or the replacement with new finishes; repair options for the various degrees of damage to the wood panels, incorporation of new replacement panels, and anticipate potential similar catastrophic events in the future.

The remaining panels were measured, documented and classified by the extent of damage. Drawings were produced that recorded each panels’ location relative to the adjacent panel and position on the wall and compass orientation. It was determined that each panel and spline were individually blind nailed to a wood lath support grid which was in turn directly fastened to a back-up clay tile wall. Remaining panel construction from the south wall provided evidence of the construction techniques. As a result, it was determined to the remove the panels in an assembly as large as practical for transportation to a controlled restoration shop environment.  At the shop, a more thorough, up-close evaluation of the damage was surveyed. During review of the restoration options, discussion ensued over the incorporation of pre-existing conditions, post fire damage, to include evidence of repair, or should all the panels have a uniform appearance.

After considering the impossibility of achieving uniformity with new panels and cleaned and repaired panels, it was decided to remove all finishes, including the protective shellac, by sanding to bare wood. Following the removal process, each panel was stained to match a patina color visible on a panel protected from damage. The final clear coat was a catalyzed finish formulated to provide long-term protection.

To further embellish the Governor’s Suite, a map of the State of Oregon was painted by Barry Faulkner, signed and dated in 1938. The work was framed within the wood paneling over the marble mantel on the ­East end of the Governor’s Suite. Faulkner painted the work in oil on canvas that was subsequently marouflaged to a section of the wall.  This section of the wall was clearly part of the original design of the room and was reserved and prepared especially for the painting. As was customary in New Deal era murals, Faulkner’s work was painted on canvas off site and then adhered to the wall when the construction process was advanced or complete.  Also quite typical of New Deal murals was the use of a lead paste adhesive for the marouflage, which was suggested in the later W.P.A project guidelines to the artists.  The presence of the lead paste adhesive proved to be decisive in the formulation of a method for the deinstallation of the piece.  The tenacity of the adhesion of the canvas back to the plaster via the lead paste is such that separation of the canvas from the plaster was impossible, and so the entire section of wall needed to be removed intact for the conservation treatment. The section of wood framing was carefully removed from the clay tile wall substrate by severing the nails that fastened the wood to the tile, and cutting the vertical studs above and below the work. Special precautions were made to protect the fragile paint surface during transport of the work to the conservation lab.

The fire’s effects caused extreme heat damage to the painting primarily in the upper and right areas of the composition, with numerous areas of blistered paint, and many sections of blistered delamination of the canvas from the substrate plaster. The combustible by-products of the fire combined with embedded soot and smoke created a deposited layer of darkened material that obscured the image. The solubility testing results were consistent with the combustible origin of the fire, and a solution of organic solvents was used to remove the deposited surface material, revealing the original chromatic palette of the work. It also became evident that the painting had been cleaned in a previous treatment.  The fragile areas of heat-blistered paint were consolidated and smoothed.  The areas of blistered delamination were brought back into plane with localized use of humidity and mild head and then, once smoothed into place, were adhered to the substrate plaster. The large blister in the upper right corner of the painting protruded 1 ½” from the plaster surface.  Areas of loss were filled, textured and retouched to match the original surface and color.  A protective layer of varnish was applied to the painting.

The exposed finish plaster surrounding the painting was also cleaned with dry sponges, consolidated and filled. Some original pencil drawings by the artist were found on the plaster that had been hidden under the paneled frame.

The most extreme heat damaged areas were irreversibly altered in both their color and texture, and the full extent of the color shift was not revealed until after the cleaning process.  In these darkened areas, Gamblin conservation colors were applied over the varnish layer to retouch the creamy yellow ground color only, leaving the darkened red color of the letters in THE STATE OF OREGON untouched. This manner of retouching allowed the painting to acquire a more finished appearance in line with the decisions made regarding the restoration of the wood paneling, while conserving also the memory of the history of the piece.  

A special thanks to Nina Olsson, Nina Olsson Art Conservation, LLC, who helped write this post in conjunction with Peter Meijer. Nina Olsson Art Conservation , LLC is a private practice for the conservation of paintings and polychrome sculpture based in Portland, Oregon.

Brutalism. The Ugly Face of Preservation.

In recent months there has been much discussion and conflict over the preservation of architecture from the Modern Movement. Structures that once represented the technological and artistic triumphs of the architect from the mid-twentieth century are viewed as unruly intrusions to the environment around them, especially Brutalist style structures. Brutalism represents an aesthetic of architectural design and planning that is rational, geometric, stripped of ornamentation, and predominantly composed of corrugated concrete. This style was initiated by Le Corbusier whose architecture was perhaps the “brutal reaction to the machine mass-produced Miesian building types” born in the post-World War II era.[1]

While we have come to slowly accept, as significant to our architectural history, the glass curtain wall machine-like jewels from one camp of the Modern Movement, we are quick to deny claim and significance to those rugged, concrete, man-made structures of the Brutalist style. Why? They are aesthetically unattractive. Brutalist structures are testaments to urban ideals for civic and educational facilities of the Modern Movement. They also project attitudes of raw unforgiving dominance, and were built by some of the world’s most forward thinking architects. Yet, Brutalism has and is continued to be met with severe criticism and cold reception. Criticism is continually directed towards the design and rough aesthetic qualities of the structures facades, but also for how their corrugated concrete does not mix well with damp climates. No wonder vocal disdain was heard loud and clear at the University of Oregon campus during the late 1970s, implementing the initiation of The Oregon Experiment.[2]

Still, today there are cries for the demolition of Brutalist structures, many of which are called architectural eye-sores or more simply, ugly. Two of Paul Rudolph’s designs, The Orange County Government Center of 1958 and Sarasota High School of 1960 have been in the spotlight of the demolition or renovation debate. Acceptance of Brutalism has been rough from the beginning, and history has proved it is not getting easier. However, we must preserve structures from the Modern Movement, even the declared eye-sores, because they are significant markers of our architectural history. The Brutalist style of architecture offered an alternative and direct challenge to the glass curtain wall that was a dominant characteristic of urban renewal and planning during the Modern Movement. Brutalism was the bold statement to the passivity of glass curtain wall design, and perhaps the closest bridging of conceptual architectural drawings and building.[3]

Perhaps a more pressing issue is why is there a lack of value associated with preserving architecture from the Modern Movement. Even the more favored glass curtain wall structures are still met with uncertainty in regards to preservation. Let’s not forget that Veterans Memorial Coliseum once faced cries for demolition, despite its intellectual display of form and material.  Structures from the Modern Movement are historical documents that attest to the cultural, social, economic, technological, and artistic climates of the eras in which they were conceived. Yet, preservationists are met with ferocious declarations of demolition once these structures begin to show any signs of weathering and aging, which prompts the reminder that for some they are also aesthetically disappointing and offensive.

Preservationists have to ask the more difficult questions of which structures should be saved, and why. Preservation becomes problematic because a set of criteria has been created that ultimately judges the significance of a structure not only for the manners in which it was conceived, but as part of our “perceived architectural heritage.”[4] Declaring a structure(s) as part of our cultures architectural heritage further complicates the preservationists roll because it is then implied that the structure(s) has been significant to the contribution of our current cultural identity.[5] Have structures executed in the Brutalist style been significant towards the contribution to our cultural heritage?  Perhaps not, but they are important markers in our architectural history.

Should structures executed in the Brutalist style be wiped clean from our architectural history? No, but this style should not be fostered, recreated, and executed again. And one of the best manners in which to ensure this is to keep a physical and visual historical record. Preservation cannot be for the aesthetically pleasing only, because our architectural history would be stripped bare and left with dispassionate and boring structures. 

[1] Curcic, Slobodan. “Review of The New Brutalism. Ethic or Aesthetic by Reyner Banham.” Journal of Aesthetic Education, Vol. 3, No. 2 (1969) 171-173.

[2] University of Oregon. <http://uplan.uoregon.edu/faq/FAQPatternLanquage.html> [Accessed May 2, 2012].

[3] Rohan, Timothy R. “Rendering the Surface: Paul Rudolph’s Art and Architecture Building at Yale.” Grey Room, No. 1 (Autumn 2000) 84-107.

[4] Whiteley, Nigel. “Modern Architecture, Heritage, and Englishness.” Architectural History. (1995) 220-237.

[5] Refer to previous footnote.

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