Why home sidings can't take the damp

OWNERS OF PRACTICALLY NEW HOUSES are being clobbered by the costs of replacing water-damaged imitation wood siding. These sidings were supposed to be as good as wood or better, but many failed within just a few years.

The news last month that Weyerhaeuser had agreed to settle a class-action lawsuit involving its siding was the worst kind of deja vu.

Thousands of homeowners across the Northwest had been dealing for years with similar faulty siding from Louisiana-Pacific. Made from wood chips glued and pressed together, the siding had tendency to swell, buckle and rot when it came into regular contact with water.

Careful homebuyers such as Royce and Maura Roberts of Kirkland tried to avoid such problems.

"When we bought our house, we asked specifically about L-P, and they told us, `Don't worry - this is Weyerhaeuser,' " Maura Roberts said.

The Robertses wish they knew then what they know now. As Weyerhaeuser's announcement that it was setting aside $82 million to settle siding claims made clear, the problems with so-called "composite wood" siding go far beyond one or two companies.

In fact, over the past five years, every major North American maker of composite wood siding - hardboard and its cousin, oriented strand board, or OSB - has been sued by homeowners who claim the products are defective. Seven companies, including Weyerhaeuser and L-P, have settled class-action suits for millions of dollars. At the same time, many homeowners with L-P siding have criticized their individual payments as grossly inadequate.

Amid all the legal wrangling, one question has never been answered definitively by a court: Why does composite siding fail?

Interviews with wood scientists, construction experts and others suggest a range of factors, from the design of the house to the quality of the installation. But, the experts say, there's little doubt that composite siding is far more sensitive to moisture than natural wood, and things that cedar siding would slough off - a nail driven a fraction of an inch too deep, a less-than-perfect paint job - can be fatal to hardboard and OSB.

"If it gets wet, it's going to swell," said Joseph Loferski, wood science professor at Virginia Tech. "And if it stays wet, decay organisms are going to want to eat it."

Cedar isn't what it used to be

For decades, the siding material of choice in the Pacific Northwest was Western red cedar - specifically, heartwood from massive old-growth cedar trees.

As cedar grows, Loferski said, chemicals that are toxic to fungi and other decay-causing organisms are pushed toward the center of the tree - the heartwood. Siding cut from that wood resists decay very well. Even today, you can see inch-thick cedar siding on old Seattle homes that has barely been affected by the elements.

But today, old-growth cedar is nearly impossible to get. Most of the vast forests that covered the region 150 years ago have been cut down; nearly all that remains is protected. As early as the 1950s, manufacturers began looking for siding substitutes, and hardboard quickly became a top choice.

Hardboard is wood, sort of: It's made from small bundles of wood fiber, bound together with resins and wax and compressed under high heat and pressure. It was invented in 1924 by William Mason; Masonite, the company he founded, remains the nation's largest hardboard maker.

Builders liked hardboard because it looked like solid wood but cost much less; manufacturers liked it because it could be made from smaller, fast-growing softwoods such as pine and spruce, and it gave them a use for the scraps left after cutting lumber.

Masonite hardboard originally was used for such things as clipboards, furniture and interior paneling. Once Masonite's original patents expired, other companies began experimenting with their own hardboards. Weyerhaeuser developed its first hardboard siding in 1963, said Phil Hardwicke, Weyerhaeuser's product performance manager.

At first, hardboard siding had trouble gaining a foothold in the residential housing market. Paul Fisette, director of the building and wood technology program at the University of Massachusetts, said that when he owned a construction company 30 years ago, it was used mostly on low-priced homes. Expectations were low, Fisette said, and few people complained when it fell apart in the rain.

"I think there was an attitude about it that was like, `Oh, it's that crap,' " he said.

Al DeBonis, head of Wood Advisory Services in Millbrook, N.Y., and a hired expert for the plaintiffs in the Weyerhaeuser and Masonite class actions, agreed.

"It was cheap, and people knew that," DeBonis said. "They expected it to fall apart."

Over time, as the process improved and solid wood siding became more expensive, hardboard captured a large share of the siding market in some areas (South Florida, notably). However, its niche remained relatively small in the Northwest until recently. The big success story in composite-wood siding in this area was Louisiana-Pacific's oriented strand board (OSB).

The Portland-based company developed OSB in the mid-1970s, originally as a plywood substitute. OSB is made from thin strands of wood, predominantly aspen. The strands are aligned into an artificial grain and pressed into a thin layer; several layers are bound together to form the board. Like hardboard, OSB is held together by resins and waxes; unlike hardboard, OSB is engineered to be as stiff and strong as plywood.

After successfully launching OSB as wall sheathing, L-P introduced its Inner-Seal OSB siding in 1985. The product was wildly popular: L-P estimates that Inner-Seal was installed on 700,000 to 800,000 homes nationwide before being pulled from the market.

Vulnerable to rain, humidity

Reports that hardboard and OSB siding were prone to warp, buckle and rot in wet weather popped up in the late 1980s and early 1990s, but few paid attention until 1992. That year, the federal government concluded that Masonite's hardboard siding was prone to fail in Florida's humid climate and moved to deny federal mortgage insurance to developments that used it.

The reports of failing siding - usually Masonite, the biggest maker of hardboard, and L-P, the biggest maker of OSB - started to come in quickly after that: a 380-home development in West Palm Beach, Fla.; thousands of homes in Texas; thousands more in Oregon and Washington.

The lawsuits followed in short order. Although the manufacturers maintained, then and now, that most of the problems were due to faulty installation or maintenance, one by one they settled nationwide class-action suits: L-P in 1996, Masonite and Georgia-Pacific in 1998, Smurfit-Stone and Masonite again in 1999; ABTco in May; and, finally, Weyerhaeuser last month.

The fundamental issue, experts agree, is that water affects hardboard and OSB more critically than it affects natural wood.

All wood and wood products absorb water. The wood fibers expand when they get wet and contract when they dry. That stresses whatever is binding the fibers together.

If the natural bonds are still present, as in solid wood or plywood, the product will shrink to its original size when it dries. But if those bonds have been broken, the product weakens - and gets weaker the longer it's wet.

Because hardboard and OSB are made from wood chips, many of the wood's natural bonds are broken.

"You're building in these internal stresses, and the product wants to go back to its original size," DeBonis said. "When it absorbs moisture, either in liquid form or from the air, it wants to swell back up. Composite never goes back to its pressed size. Over time, it will get bigger and bigger - what we call `residual thickness swell.' "

A 1997 study of five commercial OSB products at varying humidity levels found consistently that the more moisture they absorbed from the air, the more they swelled and the weaker they got.

"Due to nonrecoverable thickness swelling, a significant portion of the loss will not be recovered when the products are redried to the dry state," the authors wrote in the journal Wood and Fiber Science. "These permanent-stiffness and strength losses will subsequently affect the performance of the products during service."

Swelling can cause siding panels to buckle and warp. It also can cause the panels' protective paint coating to crack, which allows more moisture to penetrate and more damage to occur. And if moisture gets behind the siding panels, Virginia Tech's Loferski said, it will never dry out completely.

Wet wood, in turn, is a feast for bacteria, fungi and other decay organisms. Unlike old-growth cedar, hardboard and OSB have no natural resistance to such organisms, which can turn a solid board into something the consistency of soggy bread.

"Wood only gives you trouble if it's wet more often than it's dry," Fisette said.

That helps explain why so many of the complaints about composite siding have come from the Northwest and the Southeast, places where it's rainy, humid or both for most of the year - "severe environments for any wood product," DeBonis said.

Both regions were home to large numbers of hardboard and OSB plants, so it's reasonable that more of the products would be sold there than elsewhere. Between 1980 and 1998, Weyerhaeuser said, California, Oregon and Washington accounted for 52 percent of its hardboard siding sales.

Another factor, Loferski said, is that new houses may lack gutters, rain spouts and wide overhangs, which help keep water off the walls of many older houses.

Installation needs unrealistic

A product so sensitive requires proper installation, manufacturers say. Their manuals are full of instructions about how to protect the siding from unwanted moisture:

Gaps must be left between adjacent boards and filled with flexible caulk, to allow room for swelling and shrinkage.

Only galvanized nails should be used. Any exposed nail holes must be caulked.

All cut ends - especially the bottom edges, called drip edges - must be sealed.

The siding should be painted on site with about two coats of acrylic latex paint - preferably with a brush.

Siding must not touch masonry or the ground.

Sloped, noncorrosive flashing should be installed behind the siding and over the trim at the windows and doors.

Manufacturers say most complaints about rotting or peeling siding can be traced to builders' failure to follow instructions.

"Our experience is that a very, very large percentage (of siding failures) have something to do with installation or maintenance," Weyerhaeuser's Hardwicke said.

Many of the siding settlements recognize the role of improper installation. The Weyerhaeuser settlement, for example, lists 13 instances of faulty installation or upkeep that would keep a homeowner from getting compensation.

But, construction experts say, such elaborate installation rules ignore the realities of how houses are built nowadays. Siding is nailed up with a gun, which can easily drive nails below the surface of the board. Paint is applied with a sprayer, and few workers stoop to shoot paint up onto the drip edges of the siding.

"In my opinion, no builder is going to go out and do every single thing that's required," Fisette said. "If you get a builder who does 75 percent of what he's supposed to do, that's pretty good."

Bruce MacKintosh, a Woodinville home inspector who inspects 300 to 350 houses a year, said he's never seen one where the siding was installed exactly according to the manufacturer's specifications.

"Let's be honest: You're lucky to get more than a heavy mist (of paint) from the builder," MacKintosh said. "But (manufacturers) want to sell the product, and if they make it sound like it's too hard to install, it's not going to sell."

The siding situation has attracted attention from investigators in several states, including Washington. In 1996, L-P agreed to pay $1.3 million to settle a case brought by the Washington Attorney General's office over Inner-Seal.

Douglas Walsh, an assistant attorney general in the office's consumer-protection division, said the office continues to investigate other siding manufacturers, although he declined to mention any by name.

"You just can't throw the product out there and say, `It performs well if it's installed right,' when you know it's not going to be installed right," Walsh said. "It's not responsible any way you look at it."

Washington isn't alone. For two years, Wisconsin has been investigating whether composite siding makers misrepresented their products' durability and ease of installation.

Bill Oemichen, Wisconsin's consumer-protection chief, declined to discuss the probe, other than to say, "We have discovered facts that make us have greater concerns about some manufacturers than others."

HUD still on the fence

Another concern, Walsh said, is whether composite siding is tested adequately before being sent to market. Most siding is designed to conform to standards set by industry organizations such as APA-The Engineered Wood Association, but some question whether laboratory tests used to gain such certification reflect the real world.

"We think that lab testing doesn't get to the core issue: How does it perform (in places) where you have constant exposure to rain and wind?" Walsh said. "Given Washington's challenging climate, these things need to be tested to make sure they'll work here before being marketed here."

The U.S. Department of Housing and Urban Development (HUD) also is considering new testing rules for composite siding. Before proposing any rules, however, department officials have asked the federal Forest Products Laboratory in Madison, Wis., to study how well industry standards predict performance.

Two years ago, the lab nailed 13 different hardboards to a test fence. The boards have been sprayed for an hour each day, research physicist Anton TenWolde said, and are exposed to the hot, humid summers and cold, snowy winters of Wisconsin.

When the boards are taken off this fall, TenWolde said, researchers will measure how much they've deformed and compare that with what the industry tests predicted.

Weyerhaeuser maintains that the vast majority of its siding is sound. Of the more than 3 billion square feet produced since 1963, Hardwicke said, less than 2 percent has been the subject of customer complaints. The $82 million that's been set aside should be enough to pay all claims, administrative costs and up to $26.4 million in attorney fees, he said.

Weyerhaeuser no longer makes hardboard siding, having sold the business in 1996. However, it continues to market the siding made by Collins Products, which owns Weyerhaeuser's Klamath Falls plant.

"The product's been around a long time and has a pretty good track record," Hardwicke said. "And we've had the benefit of looking at L-P's experience."

That experience indicates that initial estimates can be wildly off.

When L-P agreed to settle the class action in 1996, it expected to pay no more than $275 million. The company has paid out $502 million to settle 135,000 claims against Inner-Seal, said Denny Kopfmann, L-P's director of product support.

Some 16,000 claims have yet to be paid, Kopfmann said, and "a couple hundred" new ones are coming in every week. L-P is scheduled to pay another $6 million into its settlement fund before the deal's expiration in December 2003 - nowhere near enough to cover all the outstanding claims.

After 2003, Kopfmann said, L-P will decide whether to pay remaining claimants. If it does, half will be paid in 2004 and half in 2005. If it doesn't, homeowners could launch a new class-action suit.

L-P quit selling Inner-Seal in 1995 but came back into the siding market just over a year later with SmartSystem. SmartSystem is an OSB product, like Inner-Seal, but it contains more and different resins for stronger binding and moisture resistance, as well as a new edge coating intended to eliminate moisture wicking. The new product also is treated with zinc borate to resist fungi and insects.

The company also is making a greater effort to educate builders about how to install SmartSystem, Kopfmann said.

"I think we've learned from the Inner-Seal experience how important it is to look at how the product is performing in the field," he said. "We have to do a better job as manufacturers at reaching out to contractors so that this is installed properly."

So far, Kopfmann said, more than 400,000 homes have been built with SmartSystem siding or other products in the SmartSystem line. As of May 1, he said, L-P has received only 160 warranty claims.

Fisette is cautiously optimistic about the new generation of composite wood siding.

"People are learning how to work with it, and manufacturers are becoming more realistic with their installation requirements," he said.

Meanwhile, home inspector Mac Kintosh has another worry: synthetic stucco, a common alternative to wood-based siding. The polystyrene-based cladding doesn't absorb water, but it can trap moisture inside walls. That can cause the sheathing and studs - the elements that make the wall a wall - to rot away.

One class-action lawsuit involving synthetic stucco, in North Carolina, has been settled, and Mac Kintosh said it's only a matter of time before stucco achieves the notoriety of composite siding.

"By the time the litigation is done," he predicted, "it's going to make L-P look like nothing."

Drew DeSilver's phone message number is 206-464-3145. His e-mail address is ddesilver@seattletimes.com.

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Siding claim information

For general information, check the Web site of the Defective Hardboard Siding Information Center: www.4w.com/siding/index.htm. For more specific information, check with each siding manufacturer.

ABTco (hardboard siding)

-- Toll-free phone: 800-549-4465

-- Web site: www.abtcoclaims.com

-- Settlement approved: May 2000 (preliminary)

Louisiana-Pacific (Inner-Seal-brand OSB siding)

-- Toll-free phone: 800-245-2722

-- Web site: www.lpsidingclaims.com

-- Settlement approved: April 1996

Masonite (hardboard siding)

-- Toll-free phone: 800-330-2722

-- Web site: www.masoniteclaims.com/masonite/index.htm

-- Settlement approved: January 1998

Masonite: (OmniWood-brand OSB siding)

-- Toll-free phone: 800-256-6990

-- Web site: www.masoniteclaims.com/omniwood/index.htm

-- Settlement approved: January 1999

Smurfit-Stone Container (Cladwood-brand hardboard siding)

-- Toll-free phone: 888-572-3897

-- Web site: www.cladwoodclaims.com

-- Settlement approved: May 1999

Weyerhaeuser (hardboard siding)

-- Toll-free phone: 877-947-9016

-- Web site: none yet

-- Settlement approved: July 2000 (preliminary)

Georgia Pacific: The settlement period has expired, and claims can no longer be filed.

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Ups, downs of siding choices

As common as engineered-wood siding is, it's hardly the only cladding choice. Northwest homeowners have several options for siding their homes. None, however, is perfect. A rundown:

Old-growth cedar

-- Pros: Resists decay, holds paint well, easy to work with. The long-lasting siding of choice in the Pacific Northwest.

-- Cons: Almost impossible to find nowadays and quite expensive when you do.

New cedar

-- Pros: Holds up to weather better than hardboard or oriented strand board (OSB).

-- Cons: Not as decay-resistant as old-growth and more expensive than hardboard, OSB or fiber-cement.

Plywood

-- Pros: More weather-resistant than hardboard or OSB; paper facing takes paint well.

-- Cons: Costs up to twice as much as hardboard, OSB or fiber-cement trim.

Fiber-cement (such as HardiPlank)

-- Pros: Comparable cost to hardboard and OSB and has a reputation for fire- and rot-resistance.

-- Cons: Not time-tested; can be difficult to install.

Plastic (such as vinyl or polyvinyl chloride)

-- Pros: Holds up well to sun and moisture; never needs to be painted.

-- Cons: More expensive than solid wood; expands and contracts with temperature.