Trees have long been an indispensable fuel and building material since civilization first emerged. Their abundance or scarcity has had a dramatic impact on culture, demographics, economies, internal politics, technology development, and society over millennia.
The authors employ frame analysis to understand forest multiplism and fragmentation within EU forest policy. Their authors propose that an increase in frame awareness could be leveraged by policy-makers across various policy domains to strengthen policy coordination and achieve better coordination overall.
What is CLT?
Cross-laminated timber (CLT), invented in Austria during the 1990s, is relatively novel to construction industry practices. CLT panels offer superior acoustic, fire, seismic and thermal performance making them suitable for walls, floors and roofs alike.
CLT is a structural system composed of kiln-dried dimension lumber that is assembled through layer gluing at right angles to achieve strength while decreasing weight. Factory fabrication produces panels with all dimensions predetermined as well as openings cut for doors and windows before shipment to site, speeding installation considerably faster than with traditional building materials.
architects collaborate with manufacturers during the design phase to produce pieces with exact dimensions for every element of a building, thus eliminating waste and cutting down assembly time on-site. Furthermore, due to precision cuts reducing joints between interior support elements and faster build time. Anderson Anderson Architecture and UItramoderne completed one such project in only eight weeks!
CLT is another eco-friendly material. Crafted from renewable, locally sourced timber and using less energy to manufacture than concrete or steel, it absorbs more carbon emissions during production than it releases back into the atmosphere over its lifespan. This carbon negative property means long term storage.
CLT’s Origins
CLT stands for Cross Laminated Timber and refers to any product manufactured with cross-laminated timber that has been assembled using perpendicular wooden pieces glued together (see image 1). This technique produces an extremely durable product that does not contract or expand like its glulam equivalents, and therefore can be used for larger building projects such as apartment blocks or schools.
CLT has proven itself as an economical alternative to concrete and masonry in Europe’s midrise and highrise construction projects, where its widespread usage makes CLT more cost-effective. Prefabrication makes the material easy for design, fabrication and assembly on site which reduces construction time and costs significantly.
CLT is more eco-friendly than concrete or steel construction materials due to the wood’s renewable resource status; thus reducing greenhouse gas emissions by replacing fossil fuels used during manufacturing with wood fiber. Furthermore, producing CLT requires significantly less energy and machinery than producing traditional lumber products.
At present, North America boasts four main manufacturers of CLT. Two are located in the Southeast – SmartLam of Dothan Alabama and Structurlam of Conway Arkansas – both specialize in producing CLT from southern yellow pine, but both provide custom machining to accommodate other species such as Douglas-fir, western larch or Sitka spruce.
CLT’s Benefits
As CLT continues its surge in North American construction, several advantages are becoming clear that make this material an appealing option for builders. Perhaps most impressively, when obtained from FSC-certified forests, CLT can actually reduce carbon in the atmosphere by storing CO2 long term within long-lived building materials like CLT whereas concrete and steel produce considerable amounts of CO2.
CLT is also more sustainable than traditional construction materials like concrete and steel as its installation requires half of the energy of traditional methods. Plus, its lightweight panels require less material for foundations – saving both money and reducing environmental impact!
CLT construction can also be accomplished with less labourers, making the building process faster and simpler for contractors. Furthermore, panels can be prefabricated offsite to ensure greater consistency during assembly before being delivered and assembled on-site more rapidly – meaning CLT buildings can go up on schedule just like concrete structures and provide an attractive option for city high-rise building.
CLT panels can also be pre-cut and shaped to suit specific design requirements, such as round or curved walls. Furthermore, these fireproof materials have been rigorously tested beyond three hours of exposure to fire in fire tests conducted using gypsum board protection for maximum fire-resistance.
CLT’s Applications
CLT is an eco-friendly alternative to concrete and steel for floors, roofs, walls and stairs. Stronger than concrete yet up to five times lighter, CLT boasts superior thermal performance as well as larger span capabilities than its traditional construction materials.
CLT (Crafted Lumber Panels), composed of multiple layers of kiln-dried lumber glued together at right angles to each other, can be used in buildings up to 18 stories tall. CLT panels are ideal for large floor and roof elements and bridges and elevator shafts – also cantilevered floors, bridges and elevator shafts! Fabrication usually takes place in the factory before being transported and assembled on site with a crane.
CLT’s superior strength and dimensional stability allow it to reduce support beam requirements in buildings, thus cutting costs. Plus, working with CLT is easier than concrete; less people are required for placement and installation on job sites; plus it’s less susceptible to weather effects since CLT fabrication and assembly can occur without interruption from rainfall.
CLT is quickly gaining acceptance within the construction industry and may soon take its place as the material of choice for modern buildings. Furthermore, as it comes from renewable resources it offers an opportunity to reduce carbon emissions and conserve valuable timber that would otherwise fuel forest fires.