Fire performance, protection and safety in light-frame wood and mass timber buildings.
Sutherland School, North Vancouver
Photo credit: Gord Wylie
Wood buildings are fire safe
Today’s modern wood-frame and mass timber buildings have a proven fire safety record. Effective design and the use of state-of-the-art fire protection technologies in timber structures provide added assurance and help save lives.
Meeting the same fire performance demands as any other material
The risk of fire is a concern for all buildings and construction sites. Every building material can suffer damage from prolonged exposure to fire: steel buckles, concrete spalls and wood burns. In response, the building industry has developed technologies and evolved building codes over the last half-century to dramatically reduce the negative impacts of fire and help ensure fire-safe construction. This includes taking full advantage of fire-retardant materials, sophisticated fire detection such as optical smoke sensors, advanced sprinkler and alarm systems and other smart building technologies.
Building codes, in British Columbia, and throughout North America, ensure your safety. They’re a proven set of performance-based objectives that all buildings must comply with. Recent advancements in BC and around the world permit taller wood construction. Such code changes are based on rigorous research and developed by experts through a collaborative process that includes input from all segments of the building community.
King David High School, Vancouver
Photo credit: Martin Tessler
Light-frame wood buildings' proven safety record
Light-frame wood construction has a long-standing safety record in British Columbia. It is used in the vast majority of single-family homes and multi-family projects up to six storeys. While the structure may be made entirely of wood, protective materials such as gypsum wallboard can provide fire resistance as needed. Light-frame wood assemblies can resist the effects of a fire for up to two hours through design and fire-resistant materials. And research shows that light-frame wood construction is just as safe as other building types.
Photo credit: Nik West
MASS TIMBER TESTING
Taking the heat
This video by Wood WORKS! BC provides an overview of a WoodWORKS! BC workshop at the City of Surrey Fire Department Training Facility which demonstrates fire performance with a live burn of three large demonstration boxes, including one of mass timber, and summarizes the learning outcomes essential for understanding taller and larger wood building fire requirements.
During a fire resistance test, a mass timber panel (5-ply cross-laminated timber CLT) wallwas subjected to temperatures exceeding 980 degrees Celsius. Its structural capacity persisted for over three hours, more than building codes require. This was the case even when it was not encapsulated with fire-resistant cladding.For added safety, mass timber construction that uses panels for floor and load-bearing walls help compartmentalize a fire—stopping it from spreading to other parts of a building.
Additional fire protection can be added by encapsulating the mass timber with a protective layer, as required in building code for taller wood buildings in BC. Mass timber, as is the case with other wood products, can be treated with fire retardants to increase their fire performance such as delaying time to ignition, reducing the rate heat is released and lowering the spread of flames.
Delbrook Community Recreation Centre, North Vancouver
Photo credit: Ed White Photographics
CRACKING THE CODE
Handy tool helps designers meet codes using wood
CodeCHEK, developed under the Wood WORKS! program by the Canadian Wood Council allows users to test which type of wood construction can meet code and fire protection requirements. From light-frame wood and heavy timber to exposed and encapsulated mass timber, this tool can help troubleshoot different design options and evaluate which wood elements are permitted.
How the tallest timber building in BC might be the safest
In the case of Brock Commons, an 18-storey timber tower, the design team took extensive measures to boost fire protection. As result, the building’s design was embraced by the local firefighting community. “I would call this extremely safe from a fire perspective. It’s a very safe building,” said Ray Bryant assistant chief of community safety in the City of Vancouver.
Local and international experts reviewed the building’s fire safety solutions to meet stringent standards. This included the encapsulation of the mass timber elements in the gypsum board to achieve the required fire-resistance rating and a sprinkler system with an on-site backup water tank and fire pump. “They’ve sealed every floor and every compartment. If a fire does start somewhere, it will not spread beyond the compartment,” noted Chuck Stanford, chief training officer at Vancouver Fire and Rescue Services.
Brock Commons Tallwood House, UBC
Photo credit: Michael Elkan Photography