July 23, 2018

Crews use DLT panels for the roof of small office space on Lake Union

Photo by Ed Sozinho [enlarge]

Each panel weighs two tons and measures about 34-by-7 feet.

Rendering by Patano Studio Architecture [enlarge]

The dowel laminated timber panels at Western Yacht Harbor were made in Canada and lifted into place by a floating crane.

The roof and ceiling of an office project at 2412 Westlake Ave. N. on Lake Union are being built with dowel laminated timber, a prefabricated, panelized mass timber product that the architect said has never been used before on the West Coast.

Patano Studio Architecture designed the 1,900-square-foot single-story glass and wood structure, which will sit atop the roof of Western Yacht Harbor, a privately owned marina.

It will replace an office building that was damaged in a fire on Nov. 2, 2015.

Patano said DLT is similar to cross laminated timber but no glues or mechanical adhesives are used to assemble the panels, and it is only a single-span product. CLT is a two-way spanning product.

Patano is overseeing construction on the Lake Union project. Constructive Energy is the contractor and Seattle Structural is providing structural engineering, project management and permitting support.

Patano said in a press release that the DLT was fabricated in Canada by StructureCraft. Ten panels — 34'-6” by 7'-5” and weighing nearly two tons each — were trucked from Canada, loaded onto a barge, and then floated into the marina.

A floating crane alongside the barge was used to lift the panels into position for installation.

As the DLT panels were placed, the team set infill strips to fasten them together, and screwed them to the walls and beams below.

The roof installation was completed in one day, Patano said.

Construction is slated to be done this fall. Western Yacht Harbor will lease out the new office space, with Leah Hover of CBRE as the listing agent.

Patano said this is only the second building in the U.S. to use DLT, which has been used for decades in Europe.

DLT, or brettstapel as it's known in Germany, went through several iterations, including a nailed version, and variations with dowels. There are several fabricators in Germany, Austria and Switzerland, and Patano said brettstapel can be found on a variety of project types, from houses to multistory buildings, including the 7-story e3 baugruppe in Berlin. The collective housing project was developed by residents, and designed by Kaden Klingbeil Architekten.