EUGENE, Ore. — Squeaky floors have been around as long as wood has been used for houses, but an innovative wood products manufacturer has declared all-out war on them.
Trus Joist Corp., a Boise, Ida.-based firm that has plants in Eugene, Chino, Calif. and other cities around the nation, claims to have the solution to squeaky floors. It amounts to nothing less than going back to the source of the problem and re-engineering wood joists.
"Most ordinary lumber joists will split, warp, and shrink in size as they begin to dry out in the floor of a home," explained Bruce Manchester, plant manager of Trus Joist Corp.'s Eugene plant. "When the floorboard separates from an uneven joist, it will rub against the pulled nail, causing a squeak."
The problem is compounded by the extensive use of green lumber--lumber with a great deal of moisture left in it.
Carpenters love to use green lumber because it is easy to nail without the wood splitting, but its lack of dimensional stability is the source of many problems, from squeaky floors to sticky doors and windows and nails popping out of drywall panels.
Manchester, a Southern California transplant who graduated from USC, said that the 27-year-old Trus Joist Corp. has solved the problem of dimensional stability by building up joists and beams from layers of thin, dried veneers. Each is visually and ultrasonically graded to meet the company's high standards.
The veneers are then laid up in a precisely controlled pattern with the grain running parallel, unlike plywood, where the plies are criss-crossed. The sheets are permanently bonded with waterproof glue under heat and pressure in a continuous process.
"We've done nothing less than take apart the round tree, reconstructing it to disperse its defects and improve its consistency and strength," Manchester said.
What comes out at the end of a machine that could be part of the set of the classic Charlie Chaplin movie "Modern Times" is the basis of two major Trus Joist products: TJI joists and Micro=Lam laminated veneer lumber headers and beams.
TJI joists, developed about 1969, are wooden I-beams, with the vertical section (web) made up of machined plywood and the short horizontal pieces (flange) cut from Micro=Lam (LVL) billets.
Micro=Lam (LVL) beams and headers, introduced in 1978, are also cut from the two-foot-wide billets of laminated veneered lumber, the technical name for the product, according to W.H. Cooley, Manchester's predecessor as plant manager and a veteran wood products man. He headed the Eugene factory when it manufactured plywood, before it was acquired by Trus Joist.
Failure at Glue Joint
TJI joists come in continuous lengths up to 80 feet, requiring less blocking and bridging. They are also far lighter than solid wood joists with no sacrifice in strength, Cooley said as a reporter watched a technician attempt to destroy a section of TJI joist in the plant's testing facility. The failure occurred at 4,700 pounds and came at the web's glue joint--exactly as planned.
Realizing that the average person doesn't care what goes into a new house as long at it performs properly, Craig Bodmer, the firm's communication's director, and its advertising agency, Morton Cole & Weber, Portland, Ore., came up with a multi-page ad for shelter magazines dealing with "The Mystery of The Squeaky Floor."
Using nontechnical language, the advertisement, running in consumer and trade magazines such as Home, Practical Homeowner, Builder and Professional Builder, shows how green lumber warps, splits and causes squeaks--often years after the house is finished.
"We've also prepared a video for builders and contractors showing how to use TJI and Micro=Lam products to eliminate building defects and call-backs," Bodmer said.
Developed in the late 1960s by Trus Joist co-founder Art Troutner, TJI joists quickly gained acceptance by all major building code organizations and by the Federal Housing Administration, according to Marv Askey, regional sales manager for the Chino-based inland sales office.
"Colorado--especially the Front Range cities like Colorado Springs, Denver and Boulder--quickly accepted TJI joists for residential and commercial applications," Askey said. "The product was widely accepted in New England, beginning in the 1970s, and Milwaukee and other Midwestern cities were major markets early on."
Surprisingly, California was a holdout until recently: The widespread use of slab-on-grade houses and the popularity--until recently--of single-level buildings were obstacles in the path of greater acceptance of his firm's products in California.
'Wise to the Advantages'