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

Alaska Airlines Hangar

Western Wood Structures received an inquiry from the Facilities Project Manager of Alaska Airlines in January of 2006. He contacted us because the Bowstring Trusses in their Anchorage aircraft hangar were failing. These trusses had been evaluated and “repaired” less than three years earlier and as it was presented to us “the previous structural improvements were apparently insufficient to prevent additional failures.”

The first step in meeting the needs of this client was to make a site inspection to evaluate the condition of the trusses and to map out their configuration as the original drawings were not available. Based on this initial inspection, we recommended shoring of the entire roof system be installed immediately. We then completed a structural analysis which enabled us to make the required repair recommendations and our proposal to perform these repairs was accepted.

The original hangar was built in 1954 and the hangar was added on to several years later. As a result, there were two types of Bowstring Trusses in this building – Arch Teco Trusses that were constructed from solid sawn lumber in a multiple leaf system and Tim Trusses which were constructed from Glulam. The repairs were extensive and included the following:

• All of the lower chords in the Arch Teco type trusses were replaced. The lower chords of all trusses were post tensioned using ½’ high strength cable to reduce the tension stresses in the wood members.
• All webs that exceeded an L/d ratio of 50 were stiffened by adding new structural members with screws and epoxy.
• The top chords of all trusses were strengthened by adding structural members to the sides with lag screws and epoxy.
• All web to top & bottom chord connections were strengthened using structural steel shapes.
• T-Struts were added to the lower chords of all trusses because the post tensioning cables placed the lower chords in compression.

From experience we know that Bowstring Trusses of these types have been affected by a series of changes that have rendered many of them as “dangerous members” as defined by International Existing Building Code which is further explained here. The factors described in this article contributed to the problems in this building but issues which were specific to this project added further. For instance, over framing was added which increased the dead load significantly. In addition, a drifting condition was introduced to the structure when new bay doors were added to the ends of the building. Finally, the snow load in Anchorage had been increased by code from 40 psf to 70 psf since the original building had been built.



Now that the repairs are completed, the trusses are in better condition than they day they were built and Alaska Airlines can count on the use of their hangar for many years.

Western Wood Structures was sought out for this project because of our expertise in this type of work and because we carry both an engineer’s license in Alaska as well as a contractor’s license. And it’s always rewarding to receive a nice letter from a client following the completion of a project.

The Cosumnes River Bridge

Welcome to “Working Wonders With Wood”. My goal with this is twofold: 1) to utilize this space to spotlight recent projects that Western Wood Structures has been involved in, and 2) to make an attempt to keep people abreast of recent developments and changes in our industry.

Western Wood Structures is a sales and engineering company founded in 1969. Our product lines include timber bridges, heavy timber trusses, Arches, Glulam beams, and laminated decking with our primary focus on the commercial market. Many of the projects we sell are designed in house. We also fabricate some of the projects we sell in our shop as well as install some of them with our own field crews. Sometimes we act as a material supplier and sometimes as a sub-contractor depending on factors such as project location, current work load, and customer needs. It is not uncommon for a project to start out as conceptual and pass through every department here from sales to engineering to fabrication shop to our guys in the field after it becomes an order.

Western Wood Structures offers inspection services of existing timber buildings, primarily roof systems. We are often hired to make a site inspection, run an analysis, determine the cause of any problem, and make remedial recommendations. We can then design and implement structural repairs and code upgrades to timber beams and trusses which usually involve post tensioning, shear dowel reinforcement, or other strengthening methods. There will be more on this subject another time.

This first monthly entry will focus on one of our many outstanding timber bridges: The Cosumnes River Pedestrian Bridge outside of Rancho Murieta, California. This bridge measures 410’ in length with a center span of 200’ and side spans of 105’. It is 12’ wide and was constructed primarily for pedestrian traffic, golf carts, and bicycles but it is also designed to carry a 10,000 lb. maintenance vehicle. It was required by conditional use permit when property in the Rancho Murieta South housing development near Sacramento was developed for residential use.

Western Wood Structures worked under a General Contractor, Viking Construction of Rancho Cordova, CA. Quincy Engineers of Sacramento was responsible for the civil work as well as the design of the concrete abutments.

The main carrying members are Glulam Trusses. The main span features bowstring trusses while the outer spans are parallel chords. The top chords feature a reverse continuous curve to form a flowing appearance. The curved shape of the bridge was proposed by WWS to provide a deep section in the main span as well as a smooth transition to the outside spans. The reverse in curvature begins in the side span and the point of reversal takes place in the first top chord splice in the main span. A continual graceful curve from end to end was achieved and of course splices were introduced to allow for shipment and pressure treating. The curvature gives this massive bridge a sleek appearance. Glulam floor beams support the 2-1/2” thick Glulam deck panels to form the deck and the floor beams are located at panel points so the trusses are not point loaded.

The analysis determined the radii of the truss top chords and this information was transferred to our fabrication shop where they trusses were laid out, fabricated, and match-marked. All holes were drilled in the Glulam prior to pressure treating using the steel as templates which allows for a proper treating envelope around the entire member. This extra step will help to protect the member from insect or fungal attack. Western Wood Structures believes that a treated timber bridge will easily have a life span of 75 years if it is pressure treated, fabricated before treatment, and properly maintained.

Western Wood Structures crews assembled each truss on site including much of the deck prior to erection. Viking Construction was able to build a crane pad near the river to allow the crane to set up near the main span thus minimizing the reach of the main span which weighed almost 130,000 lbs. representing the heaviest lift Western Wood Structures has ever made. Each side span was just under half this weight. Jobsite assembly and erection took a 5 person crew six weeks to complete.

This magnificent treated timber bridge is not only functional and affordable but was also able to achieve all of the aesthetic requirements of the project. It provides the access needed for the residents while allowing greater utilization and appreciation of the community’s waterway.

We are very proud of the awards this bridge has won since its completion. It earned a Merit Award of Engineering Excellence from the Consulting Engineers and Land Surveyors of California [CELSOC] in 2008. And just last month it earned a Timber Bridge Design award from the California Region of Woodworks in the non-residential category.

I hope that you will check back monthly. We welcome your questions and comments.