Glulam Specifications

Specifications for Glued-Laminated Timber or “Glulams” are usually found in Division 06180 of the CSI numbering format. Specifications are written by the specifier in order to establish the standards by which the supplier or installer of the product is expected to adhere. We are providing a sample specification for those who wish to keep current as many things have changed over the years. By clicking on the link below you will be able to view and copy this sample specification.

The Ford Foundation Building

Roseburg, Oregon







Specifications of Glued-Laminated Timber Sample

Lower Burnett Road Bridge

The Foothills Rails-to Trails coalition of Buckley, Washington working in conjunction with Pierce County, had been seeking a link to connect the north and south sides of the Foothills Trail to replace the original railroad trestle that had been removed some years prior. The result is this stunning Arched Bridge that Western Wood Structures designed, fabricated, and installed.

The use of 3D modeling made possible for the bridge components to be fully fabricated prior to pressure treatment which in turn allowed Western Wood crews to complete the complex installation in less than two months. The overall length of the 3-span bridge is nearly 400 feet including approach spans and when complete the trail will measure more than 28 miles in length.

The use of pressure treated Douglas Fir Glulam as a bridge material perfectly complements the natural beauty of the wooded site.

STRUCTURE Magazine, October 2010 article

Dominion Creek Trestle

This 100 year old former Milwaukee Railroad trestle that once carried freight trains through the Montana backcountry is being retrofitted as part of a Rails to Trails project to accommodate bicycles, ATVs, and snowmobiles. This project was made possible thanks to $850,000 in Federal stimulus funding and will open miles of the Milwaukee Road passage through the dense forest toward St. Regis, Montana.

Western Wood Structures supplied the pressure treated 6.75” thick Glulam deck panels which were segmented to match the curve of the trestle. The walkway, which measures about 650 feet and rests 100-feet above Dominion Creek, is 12’ wide with 3-foot pedestrian walkways on either side. The project will be 80% complete before the snow flies this year with final completion scheduled for next spring.

The General Contractor is Dick Anderson Construction of Great Falls, Montana. Western Wood Structures met the tight shipping schedule by having the pressure treated Douglas Fir Glulams delivered in 8 to 9 weeks.

Nisqually River Estuary Boardwalk

Federal stimulus money was used to finance construction of the Nisqually River estuary boardwalk at the Nisqually River National Wildlife Refuge. The mile-long boardwalk is nearly half done and when complete it will be used to provide access out into the world of mudflats and tidal sloughs teeming with marine life and birds.

The project has reclaimed about 762 acres of the refuge, turning the delta back into the estuary and saltwater marsh it was before it was diked 100 years ago to create farmland. The goal is to restore habitat for salmon, shorebirds, and other creatures that thrive in estuaries.

The boardwalk superstructure is constructed from pressure treated Douglas fir. The preservative is ammoniacal copper zinc, or ACZA, which is approved for use by the U.S. Environmental Protection Agency. The decking is Port Orford Cedar Glulam. The boardwalk will have a life expectancy of 50 to 75 years. The U.S. Fish & Wildlife Service considered re-cycled materials for construction of this boardwalk but wood was chosen for its durability and strength.

Western Wood Structures designed this timber boardwalk and is in the midst of fabricating and shipping materials as of this writing. The General Contractor is Five Rivers Construction of Longview, Washington.

Award Winning Bridges

Western Wood Structures has been designing and selling treated timber bridges for 40 years. We have been fortunate enough to have been involved in some very interesting projects and our bridge sales have led us to nearly every state in the union plus Japan, Taiwan, and China. We are proud to show off some of our award winning bridges.

Award Winning Timber Bridges

The Anaheim Ice Arena

Engineered wood was chosen by Architect Frank Gehry for construction of the Anaheim Ice Arena for two reasons: budget and aesthetics. According to the Matt Construction, General Contractor, structural steel had originally been selected as the primary structural building product but the owner’s budget could not be met with steel. So after consulting with Western Wood Structures the switch to Glulam took place and the result was an affordable building that is aesthetically pleasing.

Eleven rows of large double-curved Glulam beams spaced at 24’ centers span two ice rinks in a saddle-shape. The main Glulams follow the curved shape of the exterior building profile and from the outside the curvature of the roof system resembles “mouse ears” a look that the owner, Disney Development, was seeking.

Moment splices were utilized to facilitate shipment of the curved Southern Yellow Pine Glulams from Albert Lea, Minnesota to downtown Anaheim.

The purlins are solid sawn Douglas fir timbers spaced at 48” centers and the roof sheathing is 1-1/8” T & G plywood. Installing the thick plywood to the 75-foot radius of the roof structure was not an easy task. The end walls are constructed of Glulam columns, sawn timber horizontal girts, and ½” fire retardant treated plywood. The arena meets the city fire codes because it is designed as Heavy Timber construction.


The dual rink facility has an NHL sized ice rink to meet the practice needs of the Anaheim Mighty Ducks and an Olympic sized rink to meet the community recreational skating needs as well as youth hockey leagues. Western Wood Structures installed this 88,000 s/f roof system in just 3 months.

Anaheim Ice Rink Case Study

Portland Bulk Terminals

Western Wood Structures was awarded a contract in 1995 to design and construct a Heavy Timber building on the banks of the Willamette River at Terminal 5 on property owned by the Port of Portland. The clear-span building measured 160’ x 1475’ and is used to store potash, a salt-like fertilizer that is mined in Eastern Canada, railed to Portland, and stored until ready for export across the Pacific.

Potash is highly corrosive to metal which makes engineered wood the perfect choice of building components. The steel connections used in this building required a special three-step epoxy coating to protect it from exposure to the potash. A metal building for an application such as this would have been cost prohibitive.

Glulam Arches are spaced typically at 32’ centers to carry the main roof loads. Glulam purlins are spaced at 4’ centers between the Arches and the roof is sheathed with 1-1/8” T & G plywood. All city fire codes were satisfied due to the Type IV Heavy Timber design employed.

Each Arch was pinned at the concrete abutments and at the top as well. This allowed for much of the roof framing to be accomplished on the ground making erection much easier as the frames were lifted and pinned in pairs.

One end wall was panelized in sections in anticipation of future expansion. It was planned that this wall would some day be dismantled and re-used when the building was added on to.

In 2006 Western Wood was awarded the contract to design and construct the anticipated addition. This addition increased the length of the existing structure by 608’ resulting in a building that now measures 160’ x 2155’. The building is now the equivalent of six football fields in length. The floor area is now 344,800 s/f and to our knowledge this building is now the largest wood framed clear-span building in Oregon. By comparison, the Tillamook Air Museum which was originally built as a blimp hangar in the 1940’s, measures 296’ x 1072’ and has a floor area of 317,312 s/f. The Chiles Center dome at the University of Portland, also a WWS project, is the largest clear-span timber building in Oregon that we know of with a diameter of 305’.

Portland Bulk Terminal Case Study