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 | Mar 13, 2017 | News
Building a house, garage or even a shed today isn’t as easy as going to the local lumberyard and buying whatever dimension of wood you need. A lot of emphasis goes into the grade of the wood and its stress and load ratings, according to Everett Brands, manager of Arrow Building Center in Glencoe. Arrow took over the former Fullerton Lumber Center on Desoto Avenue this past October.
Today, main structural pieces, such as headers, consist of LVL, or laminated veneer lumber, an engineered product typically of poplar, fir or pine. It is laminated under heat and pressure with a moisture-resistant resin and it’s stronger than typical native wood. Building codes call for the use of specific lumber grades for specific applications.
“Anything longer than six feet as a header has to be LVL,” Brands said. The LVL products range up to 36 or 48 feet long. While regular lumber could sag or bow under extreme weight, the LVL won’t. Thus LVL is typically used over windows and entries, especially with tall entries.
“We use a lot of engineered products — beams, headers and I-joists,” added Matt Smieja, manager of Simonson Lumber, just outside Hutchinson along State Highway 7 East.
Years ago, when forests were being cut for the first time, the wood tended to be of higher quality as far as grain and knots. But new stands of trees generated are of a lower grade.
From the Hutchinson Leader: https://www.crowrivermedia.com/hutchinsonleader/news/business/engineered-lumber-has-replaced-natural-lumber-in-most-key-building/article_67ee0dc7-e4d8-56c8-932e-9ca668bb40bc.html
by Web Editor | Sep 12, 2016 | News
Like much of the industry, engineered wood producers are still navigating a fickle recovery in which builders are challenged by supply constraints, tight lending, and hard-to-come-by lots. Though the market is emerging from the recession, it’s still on the slow side.
“The demand is there for 1.5 million housing units. We’re not meeting that,” says Joe Elling, director of market research for APA–The Engineered Wood Association. Production is up on a year-ago basis, “but starts could be stronger if some of these supply-side constraints were not as binding,” Elling says. “I anticipate a modest improvement in the second half of the year, but it’s still going to be agonizingly slow going forward.”
For engineered lumber manufacturers and the dealers who sell their products, the slow recovery presents both challenges and opportunities. Along with the obvious—a slower return to at-peak sales—the ongoing labor shortages have created an even stronger need for product education. At the same time, those labor constraints provide even more motivation toward using engineered products that boost efficiencies and cut back on waste.
Overall, the industry has seen a positive boost in public opinion toward wood products, be they engineered or otherwise, as high-profile projects showcase their capabilities, beauty, and warmth.
“One of the biggest things in the forest products industry today that affects EWP the most is the general feeling in the world that wood is good,” says Mike McCollum, director of engineered wood business at Roseburg. “Wood is now the first choice in everybody’s eyes. Its sustainability, its efficiencies, its workability, its natural warmth, along with the fact that it is easy to design with and easy to build with…everyone has been awakened to this idea that wood is good. Then, when you take it to the next step, everything that engineered wood brings to the construction market is highlighted even more.”
From LBM Journal: https://www.lbmjournal.com/in-depth-engineered-lumber-2/
