VOL. 111 | NO. 116 | Tuesday, June 24, 1997
Real Fcs (eng. Wood) Lj
lj 10/5 cates
Home buildings quiet revolution
Engineered wood products performance and environmental merits are contributing to their reputation as a construction alternative
By LAURIE JOHNSON
The Daily News
There is a quiet revolution taking place in the home building industry.
While all residential builders are well-versed in the use of traditional wood products such as rafters, floor joists and headers, a growing number have been adding new terms, such as trusses, I-joists and laminated veneer lumber (LVLs) to their construction vocabularies.
What do these new building terms describe?
Engineered wood products.
Engineered wood products have been rapidly gaining acceptance and recognition in both the lumber and the home building industries, becoming the products of choice for many residential builders and home remodelers.
In 1996, sales of engineered wood products reached $800 million.
Several forms of pre-fabricated wood products have been on the market for years, even decades. However, a number of factors have contributed to the building industrys current surge in interest, said Jack Merry, spokesman for APA-The Engineered Wood Association
"We think the primary reason for the increase is that the marketplace is beginning to realize their performance advantages are very good," he said. "They also make better use of available wood fiber resources."
Engineered wood is manufactured by bonding together wood strands, veneers, lumber or other forms of wood fiber, Merry said. This process produces a larger composite unit that is stronger and more durable than the sum of its parts.
Typical examples include oriented strand board, glulam timber, wood I-beams, laminated veneer lumber, parallel strand lumber, structural composite panels and plywood commonly considered the original engineered wood product.
Each piece is engineered and designed to exact tolerances, which makes it stronger and less likely to have defects, or to warp and split like dimensional lumber, said Mark Reginelli, national sales manager with 84 Lumber.
"All fabricated wood products must pass inspections that traditional lumber isnt subjected to," Reginelli said. "The wood is easier to work with because each piece is engineered exactly alike. This eliminates the need to sort through lumber stacks, sighting each piece."
"If they are engineered, they are predictable," said Danny Branum, engineered wood specialist for local building materials supplier H. W. Jenkins Co. "This allows you to catch problems before they happen."
Although engineered wood products can be used in the construction of any size home, they are most frequently used by builders for large custom homes. One beam or joist can span several rooms.
"I generally start furnishing these materials for houses when they hit 3,000 feet and up," Branum said. "They allow you to put in properly sized beams and properly sized floor systems."
"It allows you to save time by using a single engineered I-joist or floor truss to span a 24- or 28-foot length," Reginelli said. "With traditional lumber, the job would require two 2-by-10s or 2-by-12s to do the job."
Custom homes tend to have large rooms, and an engineered floor system eliminates the squeaks and popping that tend to develop in a traditional lumber floor, said builder Charles Morgan, president of the Memphis Area Home Builders Association and president of Vintage Homes.
"It also guards against the trampoline effect, that bouncy feeling you get on a big floor," he said.
The joists in some engineered floor systems also feature pre-cut holes for wiring, ductwork or plumbing, an added plus. Cutting these holes in structural joists made of traditional lumber can weaken them, Morgan said.
Since government constraints on timber wood harvesting have put a squeeze on wood fiber supplies, engineered wood products also are environmentally friendly, Merry said.
Engineered wood uses more available wood resources with little waste and can be produced from faster-growing, under-utilized and less expensive wood species.
"Some products can be produced from wood species that were previously not considered useful for building," Merry said. "These are increasingly being grown on plantations and tree farms, so it is taking the pressure off national forests and other forest resources that we, as a society, have sought to preserve."
The cost of engineered wood can be 10 to 20 percent higher, depending on the product, than that of traditional lumber, said Branum, who estimated that 10 percent of the joists his company sold were made of engineered wood.
"Engineered wood still makes up a small percentage of our sales," he said.
However, the winds of change are blowing.
According to the APA, North American production of most engineered wood products is expected to rise significantly over the next several years. Production of I-joists is expected to see the greatest increase, nearly doubling by the year 2001. Production of laminated veneer lumber is expected to increase 70 percent, glulam timber 40 percent and oriented strand board 30 percent.
Softwood plywood production is expected to decline slightly, about 2 percent, in response to rising oriented strand board capacity and because of continuing constraints on national forest timber harvests.
Overall, North American production of structural wood panels is expected to increase 12 percent by the year 2001.