CREAKING IN THE NIGHT; GREMLINS OF HOME NOISE DYING OFF THANKS TO NEW WOOD BUILDING PRODUCTS.

Byline: Gregory J. Wilcox Daily News Staff Writer

Owning a house can be a creaky experience.

Floors creak when you walk across them, windows creak when you slide them open and doors creak when you shut them. Sometimes, mostly at night when sleep is hard to come by, the whole house seems to creak.

Gremlins are at work all right and they have been on the job since the frame was nailed together. It happens because the wood used to build the house - especially plywood sheets and the solid wood joists used on the floors - can change shape as the years roll by.

But the gremlins are dying off. Now, with increasing frequency, new homes are being built with engineered wood products throughout the structure, from floor to roof.

Used as substitutes for plywood sheeting and solid wood floor joists and beams, these products make a house stronger and quieter. And while they're more expensive than traditional wood products, these engineered wood products are preferred by more and more builders because they don't warp like traditional wood and can be made from just about all parts of smaller trees, saving old-growth timber.

``This stuff is good for everybody. It's good for the environment because (we're) utilizing a resource that would otherwise just be thrown out by the mills. And it's been proven to be as strong or stronger than actual milled lumber,'' said John Diepen, owner of A Straight Line Construction Co. in Simi Valley.

The main component of an engineered floor system is an ``I-joist,'' which looks a lot like an iron I-beam.

Flanges at the top and bottom of the joist are strips of laminated veneer lumber. They are made by taking thin sheets of wood peeled from a tree trunk - Douglas fir in the West or southern pine in the East - that are then layered together with glue, heated and put under pressure to create a strong bond.

The flanges are then joined by what is called a web, which is made from a pressed-wood product called oriented strand board.

A series of I-joists are put down across the slab and then large sheets of the oriented strand board are nailed on top.

The advantage of this construction method is that it is stronger than a solid wood joist floor, the components won't warp so shimming is not needed, and the nails won't pop loose, rub against the wood and cause squeaking as the product ages.

Erik Stottrup, editor of Rural Builder and Frame Building News, which are publications of the National Frame Builders Association, said these kinds of products are good substitutes for what is known in the trade as ``solid and sawn lumber.''

``The big problem is that the quality (of solid and sawn lumber) isn't very good any more. There are a lots of twists, warps and splits and all the other things that can make two-by-10 or a two-by-six not a nice piece of wood to work with,'' he said.

Stottrup also said the dimensions of engineered lumber products are more dependable than what comes directly from trees.

And home builders are more and more dependent on the engineered products, especially I-joists.

The Engineered Wood Association said that 1997 production of wood I-joists totaled 627 million linear feet. That number is expected to double to 1.3 billion linear feet by 2002, said Jack Merry, the association's spokesman.

I-joists now total about 33 percent of the residential floor construction market and the number should jump to 40 percent this year, he said.

It is proving to be a lucrative market for TJ International, a Boise, Idaho-based lumber company that makes engineered wood products.

Last year the company's sales totaled $706 million, up 22 percent from 1996, while net income jumped to $27.5 million, up from $16.2 million. Sales to the U.S. new home construction market jumped 19 percent.

Tom Denig, the company's president and chief executive, said sales are growing because the products provide faster installation and less waste.

Prices vary depending on market conditions but the engineered products have not yet reached a point where they can be swapped on a one-for-one basis with traditional wood products.

Kevin Lindsay, president of the Lumber Association of California and Nevada and owner of Lindsay Lumber in Paramount, said the products are indeed gaining favor in the industry.

Engineered wood can be used for ceiling beams and the headers over doorways and windows.

And the oriented strand board has just about replaced plywood as a sheeting material for roofs and the the exterior walls of homes, which makes them stand up better in an earthquake.

``For about the last five years it's virtually taken the market over. There are still some old-timers who won't use it, but more and more people are willing to accept it,'' he said. ``It might be more expensive but I think you get a better product, a more stable product and I think in the long term it's going to make a better house.''

ENGINEERED WOOD PRODUCTS ARE . . .

ENVIRONMENTALLY EFFICIENT

They utilize up to 80 percent of a log, whereas a typical sawmill would use up to 50 percent.

NOT STANDARDIZED 

Because of different production methods, there is a wide variance of quality among brands.

RELATIVELY UNTESTED

The technology has been used in home building for only 25 years.

CAPTION(S):

Drawing

DRAWING: (Color) NO SQUEAK STRUCTURES

Engineered wood products have been around since the '40's but only in the last two decades have they gained popularity for use in home construction. Floors made with these products, known for their consistency, are marked by their silence.

SOURCES: Trus Joist MacMillan, ``Understanding Wood'' by R. Bruce Hoadley, ``Building with Alternatives to Lumber and Plywood'' by NAHB Research Center 

Drawing by Bradford Mar/Daily News