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Wood at Expo 67

Glue laminated beams
Plywood box beams
Wood in general

CANADIAN FOREST PRODUCTS are playing a leading role in the unique buildings of Expo 67, the Universal and International Exhibition which opened on 28 April at Montreal, Canada.

This world's fair, the first held under the auspices of the International Bureau of Exhibitions outside Europe, has adopted the theme "man and his world," a theme which has provided broad opportunities to exhibit man's past and present achievements and his hopes for the future.

Architects and engineers expressed their concepts of the future in the subthemes "man the creator" and "man in the community."

"Man the creator" provided the opportunity for imaginative architectural designs. Many of the resulting structures, the buildings of more than 60 participating countries, include the outstanding and original use of wood products.

Some of the interesting examples are described here. Where it was felt that one particular form of the many building products available from forest industries was the dominant feature of a structure, that structure has been described under the appropriate heading. A few examples of pavilions considered to exemplify tasteful use of wood in general are also described.

Glue laminated beams

Glue laminated beams have been used extensively and in manner and magnitude not common in the past. The cosmos walk features 20 Douglas fir beams, 41 meters (135 feet) in length, 2 meters (7 feet) deep and 37 centimeters 14 ½ inches) wide, with a clear span of approximately 41 meters (135 feet). They will carry pedestrian traffic between the pavilions of the United States and the U.S.S.R. The two pedestrian walkways are constructed of 2 × 6 wood1 decking laid directly over the parallel beams.

12 × 6 in = 5.1 × 15.2 cm.

The four buildings of the Place des Nations are similarly linked by a walkway, in this instance 610 meters (2,000 feet) long with 4 × 6 2 tongue and groove western spruce decking and supported by two parallel glue laminated Douglas fir beams. The largest beam is 43 meters (140 feet) long, 2 meters (7 feet) deep and 28 centimeters (11 inches) thick and has a clear span of 33 meters (108 feet) and a cantilever of 8.2 meters (27 feet). In total, 20 beams were used in the project and all were prepared with a clear sealer and varnish.

24 × 6 in = 10.2 × 15.2 cm.

The International Trade Center is an interesting example of the versatility of glue laminated products. Glue laminated beams and. posts not only form the structural framework of the center, but are used in the exterior facade for aesthetic effect as well as serving as a sun screen. The beams and posts account for 142 cubic meters (60,000 fbm), are both of Douglas fir and are 9 meters (30 feet) long, 50 centimeters (20 inches) deep and 10 centimeters (4 inches) thick, and 7.3 meters (24 feet) long and 15.2 centimeters (6 inches) square respectively. Both have been treated with a clear fire-retardant sealer. 120 cubic meters (50,000 fbm) of Douglas fir have also been used for floor decking and an unspecified amount in laminated form for interior railings and. built-in furniture. Western red cedar decking, 140 cubic meters (60,000 fbm), was used for the roof.

The novel use of glue laminated beams in the Australian pavilion is a splendid example of the flexibility of this wood product in tile hands of imaginative architects and engineers. The boomerang shaped beams forming the roof structure reiterate the country's national symbol and also function as a passage for the air-conditioning system and conduit where necessary. Three basic sizes of Douglas fir beam have been used, the largest of which is 20 meters (65 feet) on the cord, and a total of 16 beams in each quadrant. Twelve of the 16 are hollow, but all are structurally functional. The boomerangs have been set on the apex of each quadrant, which is the reverse of the usual practice when using curved members for similar applications. An edge beam on the outer perimeter and a tension ring placed part way down the boomerangs in each quadrant serve to hold the radiating boomerang beams together. The roof decking, which follows the contour of the radiating arches, is spruce.

The (Canadian pavilion, named Katimavik, the Eskimo word for meeting place, forms a pyramid complex suggestive of the crystalline nature of some of Canada's resources. There is extensive use of glue laminated beams and laminated wood for structural purposes. The three largest pyramids are 18 meters (60 feet) square and the largest beam 18 meters (60 feet) long, 90 centimeters (3 feet) deep and 40 centimeters (16 inches) thick. All of the laminated members are of Douglas fir and represent a total of 1,940 cubic meters (821,000 fbm). Throughout the interior of the exhibits a variety of Canadian woods have been used for decorative and functional purposes. Wherever painted walls have been specified, Douglas fir plywood and fireproof paint have been used, whereas western red cedar has been used extensively where a natural finish was desired. In the library, oak flooring has been used very effectively for the walls. Canadian oak has also been used for many decorative features and furniture.

FIGURE 1. - Man the Producer pavilion

The Challenges of Energy exhibit includes a display of Canada's commercially important trees. Each species in the display, known as the Forestry Court, is represented by an authentic section of a typical tree trunk of 5 to 5.5 meters (17 to 18 feet) in height. For the Douglas fir and the Sitka spruce species, only sections of a trunk are displayed. In all, 36 species have been arranged in a natural forest environment that progresses from east to west and shows each species in the correct relative geographical position.

Plywood box beams

The largest plywood beams in the world have been used by the designers of the Man in the Community pavilion to create a striking pyramid. The box beams, which vary from 2 meters (7 feet) long by 30 centimeters (1 foot) square to 24 meters (80 feet) long by 1.5 meters (5 feet) square (weighing 12 tons), form a series of stacked hexagons reaching 38 meters (124 feet) above the first hexagon. Glue laminated wood was used for the flanges of the beams and approximately 55,740 square meters (600,000 square feet) of Douglas fir plywood, 3/8-inch (10-millimeter) basis, was required, all of which was treated with clear fire-resistant sealer. Common lumber, which has been used extensively in the pavilion, is particularly noteworthy where it has been used in the form of rough sawn boards, 90 × 36 centimeters (3 feet to 14 inches), to form an earth retaining wall around each of the four exhibit rooms found on the inside periphery of the pavilion. The center of the pavilion is covered by a pool of water which is surrounded by the walkways joining the exhibition rooms. The terraced earth walls, designed to support live plants, form a scaled reproduction of the roof structure thereby preserving the central design theme
throughout the pavilion.

All of the Expo service areas A to E have used plywood beams as a supporting roof structure and 2.7-meter 9-foot stressed skin plywood wall panels to support the beams. Each beam web is composed of two adjacent sheets of 5/8-inch (16-millimeter) thick plywood, 60 centimeters (24 inches) deep, and the top and bottom flange members are of 2 × 10 3 and 2 × 4 4 lumber respectively. Two ½-inch (13-millimeter) plywood skins over 4 × 4 5 primary framing and 2 × 4 4 secondary framing form the panels. All of the plywood used, approximately 8,360 square meters (90,000 square feet) on a 3/8-inch (10-millimeter) basis, is Douglas fir and has been treated with a stain finish, or paint in the case of wall panels.

32 × 10 in = 5.1 × 25.4 cm.
42 × 4 in = 5.1 × 10.2 cm.
54 × 4 in = 10.2 × 10.2 cm.


The theme of the Pulp and Paper pavilion is projected in its roof design which is a series of abstract evergreen trees. Each tree was fabricated from 3/4-inch (19 millimeter) tongue and groove Douglas fir plywood and steel framing which has a constant 4.9-meter (16-feet) square base for each tree, but varies in height from 5 to 18 meters (16 to 60 feet). The joints were taped and the plywood sprayed with several different shades of green epoxy paint. It required 9,300 square meters (100,000 square feet) of plywood on a 3/8 -inch (10-millimeter) basis.

The themes of "man the producer" and "man the explorer" are both characterized by massive steel space frame structures covered with giant Douglas fir ½-inch (13-millimeter) plywood shingles resembling fish scales. The shingles have been treated with a wood stain and represent a total usage of 49,500 square meters (533,000 square feet) of Douglas fir plywood on a 3/8-inch (10 millimeter) basis.

The Kaleidoscope pavilion has a peripheral ring of three-sided painted plywood panels representative of a spectrum. Although the quantity of Douglas fir plywood used, 930 square meters (10,000 square feet) on a 3/8-inch (10-millimeter) basis, is not great, considerable preparation was needed. Each panel was covered with a medium density overlay of kraft paper impregnated with resins, to reduce the breakdown of the paint film.

To facilitate participation at Expo by the smaller African countries a complex known as Africa Place was created. The upper wall and roof of the structures are made up entirely of stressed skin panels of ¼-inch (6-millimeter) and 3/8-inch (10-millimeter) Douglas fir plywood which account for 28,000 square meters (300,000 square feet) on a 3/8-inch (10-millimeter) basis for the project. Exterior panels have been covered with a white neoprene hypalon roofing and interior surfaces with a clear fire-retardant varnish. The plywood funnel design creates a continuous circulation of the interior air by means of the draw developed by the bunsen effect of the natural airstream passing in front of the funnel opening.

The Expo express used approximately 3,700 square meters (40,000 square feet), 3/4-inch (19-millimeter) basis, of noncombustible plywood for decking and a considerable amount of 3/8-inch (10-millimeter) noncombustible plywood in the fabrication of the seats.

It is estimated that exclusive of displays, more than 1,400,000 square meters (15 million square feet), 3/8-inch (10-millimeter) basis, of plywood have been used at Expo.


Rough sawn Douglas fir boards over plywood create an attractive design for the exterior of the Hospitality pavilion. The boards, which are of varying dimensions and have different sides turned outward, will be left in their natural state and permitted to weather. Approximately 50 cubic meters (20,000 fbm) of lumber and 560 cubic meters (6,000 square feet) of Douglas fir plywood were used in the building.

Wood in general

Habitat 67 is presented as one answer to urban redevelopment that provides space, privacy and variety of choice. It is composed of precast concrete units set on 1-inch (2.5-centimeter) plywood floors which are in turn supported by a grid system of 4 × 6 posts, 30 centimeters (12 inclines) long and 106 centimeters (42 inches) apart. Joists of 2 × 4-inch lumber -were laid flat on top of the posts and 7.6 × 7.6-centimeter (3 × 3-inch) diagonal members were toe-nailed to the joists. Mosaic flooring 10 millimeters (3/8 inch) thick was laid over the plywood in 30 × 30-centimeter (12 × 12-inch) sheets. All of the apartment services are in the floor structure rather than the ceiling. In total, the Habitat 67 flooring used 46,500 square meters (500,000 square feet), 3/8 -inch (10-millimeter) basis, of Douglas fir plywood.

The designers of the Man the Provider pavilion have based their roof on an egg-crate pattern built up of parallel glue laminated beams with cross beams placed above. The pattern has been filled out by encasing the beams in plywood and extending the vertical webbing by means of the plywood, -up or down. A two-ply roof with 2-inch (5-centimeter ) spruce decking completes the cover. The roof required approximately 18,600 square meters (200,000 square feet) of Douglas fir plywood, 3/8-inch (10-millimeter) basis, and glue laminated beams up to 24 meters (80 feet) long, 60 centimeters (24 inches) deep and 15 centimeters (6 inches) wide with a maximum free span between the supporting steel posts of 15 meters (50 feet). Heavy-bodied resin stain was used as a finish.

The Atlantic Provinces pavilion has made use of wood products in a variety of ways. A structural roof system combining lumber and plywood is supported by massive 40-meter (130-foot) long composite laminated wood beams with a cantilever of up to 24 meters (78 feet). The total usage of plywood for the roof assembly was 2,800 square meters (30,000 square feet), 3/8-inch (10-millimeter) basis, and about a railway carload of lumber. The transporting of the trusses required three railway cars.

FIGURE 2. - Man in the Community pavilion

FIGURE 3. - The Australian pavilion

Douglas fir plywood has also been used for wall sheeting and railings. The exterior surfaces were treated in an unusual way. The sheeting was covered with an epoxy paste and stone chips of various colors, depending upon the effect desired, were stuck in the paste.

The Western Provinces pavilion is an example of how different wood building materials can be used in combination to achieve a visual concept. In appearance the building depicts the progression from east to west of the topography of the four Western Provinces. British Columbia and the western portion of Alberta are symbolized by a truncated mountain with live trees representative of various western species growing through the open top. The basic structural support for the building comes from a steel compression ring supported by eight natural Douglas fir logs, 14 meters (45 feet) in length, and radiating glue laminated lumber arches. The arches, which are parabolic in shape and up to 23 meters (77 feet) in length, in turn rest on a concrete ring retaining wall and support the roof load from the compression ring to outer perimeter. To develop the near level expanse of roof representative of the prairies, 14 Douglas fir plywood stressed skin panels, 13 meters (44 feet) long, 340 centimeters (11 feet 2 inches) wide and 40 centimeters (16 inches) deep, were used. These panels were some of the largest ever made and each was, by necessity, different in shape so that it would conform to the curvature of the pavilion structure. The upper roof (the mountain portion) was completed by laying 240 plywood stiffened panels, 122 centimeters (4 feet) wide and varying in length from 198 centimeters (6 feet 6 inches) to 488 centimeters (16 feet), directly over the lumber arches. Both the stressed skin panels and the stiffened panels were covered with extra heavy western red cedar shakes to complete a uniform exterior. There were 170 squares of hand-split and resawn shakes with 5-centimeter (2-inch) thick butts used in the roofing and a total of 3,716 square meters (40,000 square feet), 3/8-inch (10-millimeter) basis, of plywood.

Although the Quebec Industries pavilion has not used wood products extensively in any one unit, the quantity of glue laminated beams used is significant and the provision in the design for reuse of the building in a different location is important. The glue laminated beams have been used in a variety of sizes and left exposed to contribute to the diversified form desired for the building complex. Approximately 1,500 meters (5,000 linear feet) of Douglas fir beams were used, the largest of which is 20 meters (66 feet) long, 90 centimeters (36 inches) deep and 30 centimeters (12 inches) wide. All of the beams have been treated with a clear fire-resistant sealer. Since each of the sections is only bolted together at the junctions of the steel columns and channels, the buildings can be easily dismantled into sections and reassembled at a new location. The prefabricated sections were so designed that they can be assembled in any one of five ways to produce one large building or a maximum of five separate smaller buildings. The prefabricated feature also made it possible to complete the building complex in approximately two months.

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