by Web Editor | Oct 31, 2018 | News
Prescriptive requirements for wood structures up to 18 stories were among the additions preliminarily approved for the International Building Code following the work of the International Code Council’s ad-hoc Tall Wood Buildings Committee.
Wood is widely recognized as a carbon-neutral building material, but its use as a structural material has been mostly limited to residential and low-rise buildings due to its combustible nature. Through recent advances in manufacturing and engineering, wood in the form of mass timber products is increasingly attracting interest as a structural system for tall buildings.
Portland, Ore., recently saw the completion of the eight-story Carbon12, currently the tallest wood building in the United States. Still, progress has been slow in this country as compared to Europe or Canada, where the 18-story-tall Brock Commons, in Vancouver, stands as the tallest timber structure in the world. One significant issue inhibiting widespread adoption in the U.S. is prescriptive building codes, which currently limit the height of wood buildings to 85 feet, or six stories. In December 2015, the International Code Council (ICC) formed an ad-hoc committee to study the impact of tall wood buildings on the building code with the membership voting on the adoption of proposed changes on Oct. 24.
The ICC’s International Building Code (IBC) classifies a high-rise building as any building with an occupied floor 75 feet above the lowest level at which fire department vehicles can access. The 2018 IBC defines heavy timber structural members as Type IV construction, which also includes a range of wood products, such as solid sawn timber, glue-laminated members, and composite wood members. The term mass timber, however, comprises both heavy timber as well as engineered products, many of which the IBC does not reference, such as cross-laminated timber (CLT).
Heavy timber construction is currently limited to a height of 85 feet. Architects can design taller wood structures, but they must demonstrate that the design meets the prescribed code and performs as well or better than a similar concrete or steel structure. This can be a costly and time-consuming process, requiring extensive testing and documentation on the part of the design team and building owner.
Read more on this from Architect Magazine at https://www.architectmagazine.com/technology/support-for-tall-timber-reaches-new-heights-in-the-building-code_o.
by Web Editor | May 24, 2018 | News
Oregon’s U.S. Senators Jeff Merkley and Ron Wyden recently submitted a bipartisan letter urging the Committee on Agriculture, Nutrition and Forestry to include the Timber Innovation Act, which supports the development of mass timber products for building construction, in the next Farm Bill.
“We have been working to establish Oregon as a hub for mass timber products, using local timber and bolstering our forest products economy,” Merkley said. “This bill supports innovative manufacturing that creates jobs in the rural part of the state and encourages more sustainable tall wood building construction in urban parts of the state.”
“Oregon is leading the way in producing and engineering cross-laminated timber, which is revolutionizing the way our country constructs buildings,” Wyden said. “The Timber Innovation Act promotes job growth in Oregon’s timber counties and encourages the kind of Oregon entrepreneurship that can catapult our state’s economy to new heights.”
Merkley is co-leading the letter with Sen. Mike Crapo (R-ID); cosigners include Sens. Wyden, James Risch (R-ID), Amy Klobuchar (D-MN), Steven Daines (R-MT), Roger Wicker (R-MS), Gary Peters (D-MI), Angus King (I-ME) and Maria Cantwell (D-WA).
Oregon has been at the forefront of developing mass timber products, including includes cross-laminated timber (CLT), nail laminated timber, glue laminated timber, laminated strand lumber, and laminated veneer lumber. However, U.S. building codes do not currently recognize mass timber products as official construction materials, leaving the products without a standard rating system for quality, fire resistance, earthquake resistance, and more.
Read more on this from the Klamath Falls News at https://www.klamathfallsnews.org/news/merkley-wyden-urge-bipartisan-timber-innovation-act-to-be-included-in-farm-bill.
by Web Editor | Jan 29, 2018 | News
New mass timber products are becoming more widespread and encouraging builders, designers, and engineers to search for the best applications for mass timber initiatives. A few of the mass timber building products available today include:
• Cross-laminated timber
• Nail-laminated timber
• Glue-laminated timber
• Dowel-laminated timber
As they test the capabilities of these materials, designers are looking to existing mass timber buildings around the world for examples and inspiration.
Canadian and European researchers and architects began experimenting with the design of mass timber buildings in the 1970s. European timber projects have shown that weight matters with structural systems, and mass timber structures weigh up to one-third as much as their concrete counterparts. This fact has made wood construction a viable prospect in places where building height and weight are limited, such as city utilities, subway tunnels, and underground rail yards.
Due to their lighter weight, mass timber buildings are more resilient in seismic zones. They carry less inertia, so the possibility of destructive swaying goes down. This approach was recently applied in the Brock Commons tower, an 18-story college residence designed for the University of British Columbia by Canadian firm Acton Ostry Architects.
The 173-foot-tall tower combines glue-laminated columns, cross-laminated timber floor slabs, dual concrete cores, and steel connectors. The cores help to counteract wind-generated and seismic forces while anchoring the mass timber building in place. It meets structural and fire-safety regulations by utilizing a specially designed set of interdependent finishes and building materials.
From CRL: https://c-r-l.com/content-hub/mass-timber-buildings-credibility/
by Web Editor | Sep 22, 2017 | News
The production of cross-laminated timber, or CLT, has the potential to create significant job growth in the Pacific Northwest, according to a study published in July 2017 by Oregon BEST, a Portland-based nonprofit.
CLT is made of layers of glued 2-inch-thick dimensional wood crossing over each other at a 90-degree angle, creating a strong panel that can be used in tall buildings.
The 110-page study, “Advanced Wood Product Manufacturing Study for Cross-Laminated Timber Acceleration in Oregon and SW Washington,” was funded by $120,000 from the U.S. Economic Development Administration. The study included wood products companies from across the region, including D.R. Johnson in Riddle, the first structurally certified CLT producer in the U.S.
Valerie Johnson, president of D.R. Johnson, said she agrees with the study that cross-laminated timber will increase employment for rural areas in Oregon like Douglas County. D.R. Johnson started its first glue-laminated timber, or glulam, plant in 1967 in Riddle, and began producing cross-laminated timber in fall 2015.
“The community is part of the fabric of this company. It’s not only where our employees live it’s where our families have grown up and continue to live, and making this a successful venture is really important to us,” Johnson said. “We’re giving it all we can because we really want it to be successful.”
From Treesource: https://treesource.org/news/goods-and-services/cross-laminated-timber-jobs/
by Web Editor | Aug 14, 2017 | News
Roofs made from wood are one or the rarest roof types to find around these days, as concrete slab and shingles take over, according to Choice Solutions Roofing and Exteriors Co. In Oklahoma City.
Wood is not seen as strong as some other materials when it comes to construction, but in general well-maintained roofs made of wood can have a lifespan that ranges from 30 to 50 years. Having a wooden structure on top of a house has several good qualities, and it can look great. Here are some examples of wooden structures which are not the average roof that will provide an idea of how unique and marvelous structure topped off with wood can become.
The Centre Pompidou Metz has a hexagonal pattern of a load-bearing timber roof structure which is visible at night through its transparent covering membrane. It is interesting to know that the inspiration of the roof comes from a woven Chinese hat. Before this one-of-a-kind structure was created, it was studied from every angle to ensure that it would withhold heavy weather conditions. This woven like structure roof is made out of wooden beams, spaced 2.90 meters apart, forming a hexagon pattern that is 90 meters wide.
The timber used is glue laminated which enables the different lengths of the beams and makes them more resistant. It is without a doubt an astounding structure due to its complex curves and counter curves and therefore it is one of the most challenging and largest structure built up to date.
The mesh can allow the roof to expand 40 meters, made from protective fabric which consists of fiberglass and Teflon, forming a membrane over the wooden structure. This layer helps the inside temperature to stay natural. This building was created for displaying art and the goal behind the innovative structure was to draw tourism to Metz, France.
Read more on this from Woodworking Network: https://www.woodworkingnetwork.com/architectural-products/timber-structures-show-potential-wood-construction?ss=news,news,woodworking_industry_news,news,almanac_market_data,news,canadian_news
