After Raleigh apartment fire, safety of wood construction questioned
BY MARTHA QUILLIN
As flames chewed through hundreds of thousands of board feet of exposed lumber and plywood in a spectacular fire at an under-construction apartment building in downtown Raleigh Thursday night, a question swirled like smoke. Why build an apartment out of wood?
It may seem counter intuitive to see a full-scale return in 2017 to the same building materials colonists hewed from the forests when they first landed in the New World. But all over Raleigh, and especially downtown, along Hillsborough Street and around Cameron Village, wood-frame apartment buildings have proliferated in the post-recession housing-market rebirth because they’re an economical way to build highly demanded high-density housing.
“There is a trend around the country to build these types of buildings all over the place,” said Barry Gupton, secretary to the N.C. Building Code Council, the 17-member board that oversees the state’s voluminous building regulations. “They’re all over Raleigh, Charlotte, Greensboro, and other parts of the country too.”
The Metropolitan, which burned as people watched from nearby streets and over internet feeds, was one of the most common types of modern wood-frame buildings. Known as a pedestal or podium building, it’s actually two structures: a poured-concrete first level – the pedestal – with four stories of wood-frame construction on top. Another popular form is wood framing directly on a concrete slab.
A change in the national building code in 2009, adopted by North Carolina, increased the number of wood-frame stories that can be built on a pedestal or slab from four to five.
International, national and state building codes allow this type of structure and The Metropolitan passed more than four dozen city inspections, including one just a few days before the fire. Those who build them say these mid-rise light wood buildings are economical to build because of savings in labor and materials compared with concrete and steel; that they are more “green” because wood is a renewable resource; and, once the frame is enclosed in fire-resistant materials and sprinkler systems are installed, the buildings are as safe as any other type of structure.
Firefighting groups, however, have expressed concern over the growth of multi-family wood structures, saying that when a fire does occur, it can spread quickly in the right conditions and create special hazards for firefighters. Proponents of competing building materials, such as masonry, say builders who use wood for mid-rise buildings emphasize cost savings over durability and safety.
One thing they all agree on is that whatever sparked the Metropolitan fire sometime before 10 p.m. Thursday, it came at a most opportune time.
“The most vulnerable time in the life span of any building is when it’s under construction,” said Steve Schuster, a Raleigh architect with nearly 40 years’ experience. Schuster mostly repurposes older buildings, but does new construction and has built some wood frame buildings smaller than The Metropolitan. That building’s designer is JDavis Architects of Raleigh. Construction firm Clancy & Theys in Raleigh is building it.
“Anything that is partially done doesn’t have all the components that a finished structure is going to have,” Schuster said. “The very things that make a building like this safe when it’s completed weren’t there yet.”
No material fail-safe
The five-story, 241-unit, $51 million Metropolitan on North Harrington Street is a project of Banner Development, a Chicago-based company whose specialties are multi-family and senior-living developments, and self-storage structures. The company plans to rebuild on the site as soon as it is able, said Banner’s president, William Henry.
“Everything was in place,” he said. “It was just bad luck.” He estimated Friday evening that the building, which was scheduled to open this fall, was 40 percent complete.
“Whatever happened, whether it was set or it was an accident, it was exactly at the right time to maximize damage,” said Jim Anthony, CEO of Collier’s International in Raleigh, another developer of multi-family housing that uses wood-frame construction.
Whether it’s in Raleigh, Charlotte or Los Angeles, a building like this would go up in similar fashion, starting with a concrete slab. If the building includes a pedestal, which might house a parking structure or ground-floor retail or other commercial use, that’s built next, with reinforced concrete walls and top. Concrete or block is used also for stairwells and elevator shafts. One by one, the wood-frame stories go up next, most often with concrete between floors to increase fire resistance, add stability and insulate sound between units. Once the frame is up, the outside walls and roof are added to close the building off to the elements. Plumbing, heating, cooling, electrical systems and sprinklers are roughed in. Flooring is installed, along with drywall, which covers the wood and protects it from fire. As the building nears completion, heads are installed on the sprinkler system that melt when exposed to heat, releasing water directly where a fire is detected to suppress flames and give residents time to get out.
Kirk Grundahl, an engineer and executive director of the Structural Building Components Association, a trade group that represents the producers of wood framing elements, said that once completed, wood-frame buildings are no more fire-prone than structures with steel or concrete frames.
“It’s not about the wood frame,” Grundahl said. “Wood frame has been used in constructing buildings very well for society for over 200 years.”
No construction material is fail-safe in a fire, Grundahl said; at high temperatures, concrete explodes, steel buckles and glass shatters.
“It’s not the building’s fault. It not the wood’s fault,” Grundahl said. “The wood didn’t spontaneously combust. Something started the fire, and it happened at the building’s most vulnerable stage. It’s like when a baby is born, and it has no protective mechanism at all. If somebody drops the baby, what happens? It’s the same deal here.”
Lt. Shawn Burns, who has spent 21 years in the Raleigh Fire Department and is president of the fire union, agreed that wood-frame buildings are safe once finished and have sprinklers installed. State law has required sprinklers in apartments since 2006.
“The problem is when they’re going up, they’re a four-story lumber yard,” he said.
Fire Engineering, which publishes a magazine for fire service workers, has articles on its website explaining the construction of mid-rise wood-frame buildings and describing hazards it says firefighters should be aware of. In a video on the site, a New Jersey fire marshal points out avenues where fire can travel horizontally or vertically, and cautions that when a wood-frame building is engulfed, firefighters should not get over or under wood trusses.
Notable fires in modern wood-frame buildings include two in New Jersey; one in 2000 at an apartment building that was under construction and another in 2016 in a building that was finished and occupied. New Jersey is considering toughening its building codes.
A wood-frame townhome building in Raleigh caught fire in 2007 after someone tossed a cigarette onto landscaping materials. The ensuing blaze leveled more than 20 units when it traveled through the building’s soffits, and resulted in changes in the building code regarding soffit construction and landscaping materials.
A cost-effective alternative
Builders say it’s difficult to compare the costs of wood-frame construction for apartment buildings to steel or concrete because of all the variables, including building type and size and where it’s built. One trade publication says that in certain applications, up-front costs using wood can be as much as 40 percent less than with other materials. Savings come in the cost of raw materials, the speed of construction and the availability of workers trained to handle different materials. In a setting where land costs are high, developers may find a mid-rise wood-frame building an affordable way to get higher density at lower cost.
Jeff Buczkiewicz (pronounced “BUCK-uh-witz”) president and CEO of the Mason Contractors Association of America, which promotes the use of brick, block, tile, terra cotta and stone, argues that while up-front costs may be lower on a wood-frame building, masonry is more durable.
“There is economical concrete block and alternative materials that are used in low-income housing that are very competitive with wood,” Buczkiewicz said. “And in 30 years, they’re going to be in a whole lot better shape.”
Looking at photos from the fire, Buczkiewicz couldn’t help pointing out, “You see what’s still standing. It’s the block walls for the stairwells.”
The photos also show significant damage from The Metropolitan fire to its neighbor, the Link Apartments. That, too, is a multi-story wood frame building. It opened last year and is about 94 percent occupied, said Emily Ethridge, spokewoman for Grubb Properties, its developer.
The Link building did not catch fire but has heat and smoke damage on the side that faced the conflagration, and interior water damage from fire hoses and sprinklers.
Ethridge said what happened at the Link is a testament to the integrity of a wood-frame apartment building.
“The fire alarms went off, the sprinklers went off, everyone did what they were supposed to and evacuated the building,” Ethridge said. “Everything worked the way it was supposed to.”