{"id":15097,"date":"2012-12-17T14:47:44","date_gmt":"2012-12-17T19:47:44","guid":{"rendered":"http:\/\/www.constructionspecifier.com\/?p=15097"},"modified":"2017-01-20T14:51:29","modified_gmt":"2017-01-20T19:51:29","slug":"the-new-wood-architectural-ceiling-and-wall-panels-get-a-makeover","status":"publish","type":"post","link":"https:\/\/www.constructionspecifier.com\/the-new-wood-architectural-ceiling-and-wall-panels-get-a-makeover\/","title":{"rendered":"The new wood: Architectural ceiling and wall panels get a makeover"},"content":{"rendered":"
\"Photos<\/a>
Photos courtesy Ceilings Plus<\/em><\/span><\/figcaption><\/figure>\n

Wood’s beauty has long been appreciated for both architectural ceiling and wall panel assemblies.<\/p>\n

Significant changes during the past decade have led to new fabrication techniques and products complementing traditional millwork. These new materials extend the range of applications in which wood can satisfy the changing aesthetic and functional requirements of contemporary architecture.<\/p>\n

This article examines these new developments with regard to veneers, panel cores, and environmental considerations.<\/p>\n

Veneer variables<\/b>
\nIn selecting the ideal veneer for a project, there are many considerations the design professional should take into account.<\/p>\n

Species<\/i>
\nWood species go in and out of demand in response to changing architectural tastes, supply, and social factors such as market access and environmental concerns. Use of teak, for example, declined as old-growth stocks were depleted while plantation-grown eucalyptus has risen in popularity. North American hardwoods (e.g.<\/i> oak, maple, birch, and cherry) and softwoods (e.g.<\/i> pine and Douglas fir) are readily available and remain perennial favorites. Yet, designers now have unprecedented access to wood from around the world, from anigre to zebrawood.<\/p>\n

While several dozen species account for the bulk of architectural veneer, an estimated 600 commercially harvested species present a plethora of color and figure. It is important to keep in mind, however, some species vary widely in color and figure, both within a log and from log-to-log, making it challenging to find enough sufficiently compatible veneer for a large project.<\/p>\n

\"New<\/a>
New materials and techniques for fabricating wood panels have made them more affordable for use on large surfaces in projects such as this one by HDR Inc.<\/span><\/figcaption><\/figure>\n

There is also growing interest in veneers that are neither hardwood nor softwood. For example, bamboo (a grass) and palm (an herbaceous monocot) have unique fibrous structures and lack annual growth rings, resulting in grains and appearances markedly different from that of true woods.<\/p>\n

When veneer options were limited, many local and regional distributors could keep the most commonly specified species in inventory. However, diversity and an international supply chain make it advisable to discuss cost and availability with panel manufacturers before specifying an exotic specie, especially if it is to be certified as originating in a sustainably-managed forest (as discussed later in the article).<\/p>\n

Engineered veneers<\/i>
\nComplementing these options, wood can be modified to create veneers with special properties. Some processes are long-established\u2014walnut, for example, must be cooked to obtain a desirable coloration. Other techniques are more recent in origin.<\/p>\n

Reconstituted wood converts fast-growing varieties to simulate the appearance of expensive or exotic hardwoods or to create looks unavailable in nature. Wood is converted into pulp, dyes introduced, the mix blended, and then pressed into \u2018logs\u2019 that, after curing, are sliced into veneer. The carefully controlled process of compiling logs results in veneer with more consistent color and grain than natural veneer. It also has a higher use factor since less veneer has to be trimmed to remove flaws.<\/p>\n

\"After<\/a>
After logs are sliced into veneer, flitches are sorted for color. This log has been plain-sliced.<\/span><\/figcaption><\/figure>\n

Other suppliers assemble layers of lumber into a log that is then sliced into veneer. Layers of darker and lighter wood are evenly distributed so the overall visual character is more harmonious, from panel to panel and from one end of a panel to the other. The same process can also be used to create a multi-colored, striped effect by interspersing several species that have a range of tones.<\/p>\n

Techniques for creating faux wood continue to improve; some printed \u2018veneers\u2019 now have a dimensional texture that comes close to looking like real wood, and have been reformulated to be free of polyvinyl chloride (PVC). They can be used to provide greater uniformity than natural veneers, or as an economical alternative to an expensive wood. However, real wood, even if highly engineered, still has a luster and dimensionality that cannot be matched by a faux product; wood fibers interact with light in a way only a natural material can.<\/p>\n

Cutting and slicing<\/i>
\nThe appearance veneer is strongly influenced by the plane, relative to the axis of the trunk, along which it was cut or sliced out of a log. Each thin slice is called a flitch or, once it has been trimmed to size, a leaf.<\/p>\n

Pattern matching<\/i>
\nFlitches and leaves are typically bundled in the order in which they occurred in a log. This allows them to be matched, edge-to-edge, in sequence to create the required pattern. The orientation of leaves in relation to adjacent pieces determines the veneer pattern.<\/p>\n

Faces<\/i>
\nLeaves are then assembled into sheets, called \u2018faces,\u2019 that can more readily set into place over a core. Veneers must be selected and assembled to create a harmonious composition in keeping with the specified pattern and the designer\u2019s intent. The face becomes the visible surface of a panel; while specialized machinery is used throughout the process, no robot can replace the trained eye of someone that understands and appreciates wood.<\/p>\n

The process begins when skilled inspectors sort incoming bundles of flitches by color and figure. Selected leaves are arranged into the required pattern and fed through a machine that carefully glues the thin edges of veneer together; strips of tape are applied to one surface to help hold the fragile faces together. After final visual inspection, faces are sent to panel manufacturers.<\/p>\n

There, faces are adhered to a core and held tightly in place until the bond cures. Tape strips are left on the exposed surface to avoid their telegraphing through the thin veneer. Sanding removes the tape and excess glue, levels the surface, and leaves the wood ready for finishing.<\/p>\n

\"Veneer<\/a>
Veneer is trimmed and short lengths glued end-to-end to make strips. Strips are then joined edge-to-edge in order to make faces large enough for required panels.<\/span><\/figcaption><\/figure>\n

Finishing<\/i>
\nWhile any wood finish can be applied, factory production allows the use of ultraviolet (UV)-cured clear coatings that contain no volatile organic compounds (VOCs) and provide a durable, low-gloss finish. If desired, wood can be stained before coating or a colorant can be put into the coating. Wood darkens as it ages, as can be seen in the rich patina of antique wood. Specifiers should allow for this when matching new construction to existing woodwork.<\/p>\n

Some assembly required<\/i>
\nWood is a natural product, and variations in appearance are part of its beauty. Specifiers must communicate how much variation of color and figure is acceptable within an installation. It is difficult enough to find closely matching veneer for a piece of cabinetry or a small feature wall; the task becomes daunting to do so across a large ceiling or wall. Leaves within each panel must have an attractive composition, as must the array of panels throughout a space.<\/p>\n

Ironically, randomly matched panels can be most challenging in this regard. In theory, dark heartwood and light sapwood randomly installed across a surface should be evenly distributed. However, a viewer\u2019s attention is invariably drawn to distracting locations where a cluster of light-colored wood ends up next to a cluster of dark wood. These distractions can be minimized by specifying a \u2018pleasing match\u2019 with veneers selected for uniformity of color without regard to grain pattern, and working with a veneer supplier and panel manufacturer willing to work with the project team to understand and satisfy project requirements.<\/p>\n

<\/p>\n

\"Veneer<\/a>
Veneer faces are laminated to aluminum cores, sanded, and finished. This photo shows panels after application of an ultraviolet (UV)-cured coating free of volatile organic compound (VOC) emissions. The flexible sheets are made rigid and flat when edge returns are formed.<\/span><\/figcaption><\/figure>\n

Cores from cans<\/b>
\nAlmost all wood panels are made with a thin veneer, selected for aesthetics or other characteristics, adhered to a core material. Published by Architectural Woodwork Institute (AWI), Architectural Woodwork Manufacturers Association of Canada (AWMAC), and Woodwork Institute, the 2009 Architectural Woodwork <\/i>Standards<\/i> (AWS<\/i>) is a reliable reference for most architectural woodwork. It lists plywood, solid lumber, and composite wood products such as particleboard.<\/p>\n

New core materials, however, are entering the market more rapidly than can be assimilated into consensus standards. Examples include non-wood bio-based materials, resinous and composite products, and sheet metal. In particular, aluminum has been proven in use around the world and offers many features not associated with wood-based cores. This innovation is the product of advances in metallurgy, adhesives, and digital fabrication techniques.\u00a0(See the article, \u201cGetting off the Rectangular Grid,\u201d by Mercolino, Chusid, and Lee Eisner, in the May 2010 issue of The Construction Specifier<\/i>. Visit www.constructionspecifier.com<\/a> and select \u201cArchives.\u201d)<\/p>\n

Aluminum weighs 2.8 and 4.4 kg\/m2<\/sup> for 1.02- and 1.63-mm (0.57 and 0.90 psf for 0.040- and 0.064-in.) thick sheet respectively, about a quarter the weight of 20-mm (\u00be-in.) thick wood-based cores. Weight savings cut dead load on the ceiling suspension system and the building structure. More significantly, lightweight panels are easier to handle; panels can be larger than wood-core panels, yet still lifted by just one or two people. Torsion spring clips for ceiling and lift-on brackets for walls allow non-progressive installation, and panels can be removed to commission or service equipment and utilities.<\/p>\n

In addition to being non-combustible, aluminum cores are unaffected by moisture. This means they do not support mold and, because they do not warp or twist due to changes in humidity, they can be installed before a new building has dried out or even at exterior locations.<\/p>\n

Veneered aluminum core can be digitally fabricated with high-speed equipment to produce curves and tessellations. Perforations, which provide both a design element and noise reduction, can be produced in an almost unlimited variety of perforation sizes, shapes, and patterns.<\/p>\n

\"Palm<\/a>
Palm is now available as veneer, offering a bio-based material that provides fresh visual character.<\/span>
Photo courtesy Plyboo\u2014Smith & Fong<\/span><\/em><\/figcaption><\/figure>\n

An ever-green material<\/b>
\nIntrinsic environmental qualities are part of wood\u2019s natural appeal. People generally feel healthier and happier surrounded by natural materials\u2014a phenomenon called \u2018biophilia.\u2019 Forests generate oxygen, control erosion, provide habitat for wildlife, and can be managed to sustain both the ecosystem and an economic system.<\/p>\n

New methods of producing thinner veneer make increasingly efficient use of forest products\u2014a cubic meter of wood can yield 1400 m2<\/sup> of veneer (435 sf of veneer per 1 cf of wood), 0.7 mm (0.03 in.) thick or less.<\/p>\n

Wood panels can help a project earn points within the U.S. Green Building Council\u2019s (USGBC) Leadership in Energy and Environmental Design (LEED) program, including the following credits:<\/p>\n

Materials and Resources (MR) Credit 3, <\/i>Materials Reuse
\nWood panels with traditional cores can be difficult to remove without damage for reuse in another building. However, the light weight and accessibility of wood panels with aluminum cores make it practical to salvage and reuse panels.<\/p>\n

MR Credit 4, <\/i>Recycled Content
\nVeneer from salvaged timbers and palms (discussed later in this article) may also contribute to recycled content. Panel cores can be 99 percent post-consumer aluminum recycled primarily from beverage containers. If it becomes necessary to remove a panel from a building, aluminum has the added advantage of being readily recyclable without loss of metallurgical value.<\/p>\n

<\/p>\n

\"The<\/a>
The wood ceilings and walls in this community room (designed by JMZ Architects and Planners) are visible through glass fa\u00e7ades, offering a warm invitation to the public below. Subtly folded panels keep the emphasis on joint lines leading the eye to the front of the room.<\/span>
Photo \u00a9 2011 David Lamb Photography. Photo courtesy Ceilings Plus<\/em><\/span><\/figcaption><\/figure>\n

MR Credit 5, <\/i>Regional Materials
\nThis credit is based on use of wood harvested within 805 km (500 mi) of a project. While indigenous species contribute to regional architectural traditions\u2014redwood in California or cypress in Louisiana, for example\u2014designers frequently have more exotic tastes. Recent amendments to LEED allow credit calculations for rail shipments up to 2414 km (1500 mi) and sea shipment up to 12,070 km (7500 mi). This increases the palette of wood species that can be applied toward LEED credit. Sustainably harvested hardwoods from South America, for example, are within the allowed distance to North American ports.\u00a0(See LEED 2009 for New Construction and Major Renovations with Alternative Compliance Paths for Projects Outside the U.S.<\/i>, updated in October 2011.)<\/p>\n

MR Credit 6, <\/i>Rapidly Renewable Materials
\nSince bamboo reaches maturity after four to six years and regenerates itself from existing roots, it qualifies for this credit. The range of bamboo veneer patterns includes edge grain, flat grain, and reconstituted wood.<\/p>\n

It has been proposed that the next edition of LEED, due for release in 2013, revise this credit to consider bio-based materials with a range of environmental characteristics besides rapidity of growth.\u00a0(See \u201cDealing with Wood and Biobased Materials in the LEED Rating System,\u201d a white paper by Alex Wilson for USGBC that was amended on March 26, 2006.) For example, coconut and sugar palms are typically cut down after 50 or more years when they cease to be productive. The downed trunks, some as long as 21 m (70 ft), have limited structural use, and most are burned or left to decay in the field. According to a United Nations (UN) report, converting palm wood into higher value byproducts such as architectural veneer is sustainable and provides income for growers, most of whom operate small family farms.<\/p>\n

MR Credit 7, <\/i>Certified Wood
\nSafeguarding against rapacious forestry practices, such as clear-cutting, has spawned several non-governmental organizations that promulgate regulations and monitor forest product commerce. These include Programme for the Endorsement of Forest Certification (PEFC), Sustainable Forestry Initiative (SFI), and Forest Stewardship Council (FSC).<\/p>\n

\"Lightweight<\/a>
Lightweight aluminum cores allow easy handling and reduced loads. Wall panels hook onto wall-mounted standards or rails and can be removed<\/span>
for access to cables or other utilities inside the wall.<\/span>
Photo courtesy Ceilings Plus<\/span><\/em><\/figcaption><\/figure>\n

FSC\u2019s requirements are ensconced within LEED. MR Credit 7 states:<\/p>\n

Use a minimum of 50 percent (based on cost) of wood-based materials and products that are certified in accordance with the Forest Stewardship Council\u2019s principles and criteria,<\/span>
\n for wood building components.<\/span><\/p>\n

FSC\u2019s principles protect more than just trees; they recognize, for example, compliance with the law, rights of indigenous people, and the welfare of forest workers and communities.<\/p>\n

FSC has also established rules for maintaining certified wood\u2019s chain-of-custody (COC) from forest to consumer. Brokers, sawmills, distributors, and manufacturers taking possession of the wood must establish procedures to prevent wood from non-certified forests against inadvertent identification as \u2018certified.\u2019 Certified wood must be identified as such on invoices and packing slips from suppliers, and must be labeled and segregated throughout each step in its journey to a jobsite. The integrity of the process is assured by independent auditors, such as Scientific Certification Systems (SCS), that certify\u00a0a company\u2019s adherence to FSC<\/a>\u2019s rules.<\/p>\n

FSC has several categories of certified wood, including:<\/p>\n