by Web Editor | Dec 5, 2018 | News
Thanks to innovative construction materials like cross-laminated timber (CLT) and laminated veneer lumber (LVL), wooden buildings are no longer mere houses made of sticks.
Attracted by the aesthetic and environmental benefits of timber, structural engineers have overseen a lumber comeback, from Landlease’s International House development in Sydney’s Barangaroo district to Brisbane’s newly completed 25 King, which is the world’s tallest commercial timber building.
But with ambitious projects in Tokyo, Chicago, and London eyeing far greater heights for timber as a building material, engineers and the public need to be assured wood can match up with concrete and steel when it comes to safety and stability.
That’s why Griffith University’s Associate Professor Benoit Gilbert has been putting timber to the test, using high-tech machinery to better understand how timber behaves in a variety of situations.
Gilbert’s current tests focus on progressive collapse, a term that describes the severe failure of a structure due to something going wrong in one part of it. That could be a gas explosion, a fire or if a car were to collide with the building.
Read more on this from Create at https://www.createdigital.org.au/strength-safety-tests-timber/.
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 | Sep 10, 2018 | News
Construction is underway in downtown Toronto on a multi-story mixed-use project that incorporates an innovative combination of glulam and cross-laminated timber (CLT).
The timber installation, scheduled for completion in mid-September, encompasses a combined floor and roof area of 3,800 square meters. The development, located at the southwest corner of Charles and Yonge streets, is thought to be the first significant contemporary “mass timber” project to proceed in the city’s downtown core.
By definition, mass timber construction uses large, prefabricated wood members for wall, floor and roof construction. These products include glue-laminated timber and CLT. “Timber construction is definitely staking a new claim, so many years after now century-old wood buildings were being constructed in the city,” said Gary Williams, president of Timber Systems Ltd.
The Markham, Ont.-based company was awarded a contract in November 2015 to both supply and install the timber for the four-story project which incorporates an existing heritage-designated building.
The project is being carried out for Shoppers Drug Mart, now owned by Loblaw Companies, by a team that includes Toronto-based architects Brook McIlroy and structural engineers Blackwell. The two firms have collaborated on wood construction projects in the past.
For more on this from ConstructConnect visit https://canada.constructconnect.com/dcn/news/projects/2018/09/toronto-timber-build-trendsetter-developers.
by Web Editor | Aug 17, 2018 | News
Thanks to a recent addendum to Oregon’s building code, the state is the first in the country to allow timber buildings to rise higher than six stories without special consideration.
Portland has become something of a hotbed for timber innovation as of late. Carbon12, PATH Architecture’s eight-story glulam and cross-laminated timber (CLT) tower with a steel core, recently became the country’s tallest timber building and was set to be surpassed by LEVER Architecture’s 12-story Framework. Alas, that project was put on hold due to mounting financial difficulties last month, but it seems the precedent that the project achieved in securing a building permit from the State of Oregon and City of Portland will live on.
The timber allowance comes courtesy of Oregon’s statewide alternate method (SAM), a state-specific program that allows for alternate building techniques to be used after an advisory council has approved the “technical and scientific facts of the proposed alternate method.” The allowance comes after the International Code Council (ICC)–the nonprofit group that Oregon models its building codes after–established the ICC Ad Hoc Committee on Tall Wood Buildings in 2015 to explore the benefits and challenges of using timber in tall buildings.
A Committee Action Hearing was held in April of this year, where the Ad Hoc Committee, made up of code experts, stakeholders, and industry members presented their findings. All 14 of the committee’s suggestions were adopted, introducing standards and best practices for fireproofing, the load-bearing potential of CLT and heavy timber, water resistance, sealing, seismic ratings, and more.
Three new building classifications were introduced as a result: Type IV A, timber buildings permitted up to 18 stories and 270 feet tall, Type IV B, timber buildings with a maximum height of 12 stories and 180 feet, and Type IV C, which is permitted to rise nine stories and 85 feet tall at maximum. The shortest of the timber typologies is allowed to use exposed structural timber as an interior finish, whereas the tallest, type A, must enclose all exposed surfaces and include a three-hour fire-resistance rating for the structural elements.
Read more on this from The Architects Newspaper at https://archpaper.com/2018/08/oregon-legalize-mass-timber-high-rises/.
by Web Editor | Jun 22, 2018 | News
A far cry from the kitschy memorabilia of the Rock ’n’ Roll-themed building it replaces, the essentially all-new design of River North’s flagship McDonalds at 600 N. Clark Street is finally starting to come together.
At its heart is an innovative construction material known as Cross-Laminated Timber (CLT). In line with the fast food brand’s plan to reinvent its image, the sustainable building method is being employed for the first time in a commercial project in Chicago.
“One way to think about it is plywood on steroids,” Chicago-based designer Carol Ross Barney of Ross Barney Architects told Curbed Chicago. “It’s formed from smaller sized pieces of timber glued together for uniform strength.”
“CLT is versatile, and because the wood can be harvested and renewed at a more regular interval, it has a relatively low carbon footprint. You can use it like any panelized material such as precast concrete or steel. Here we’re using it as a deck structure.”
The choice to use timber came early in the process when McDonald’s first engaged Barney’s firm with the goal of design authenticity. “Some of the most durable materials aren’t very authentic,” explained the architect. “And some of the most authentic materials don’t hold up over time. CLT offers a great deal of both while reflecting the client’s commitment to sustainability.”
Read more on this from Curbed Chicago at https://chicago.curbed.com/2018/6/15/17386766/mcdonalds-ross-barneys-timber-construction.
