Foundation, Structural Framing

Here's yet another chilling reason to hire a home inspector to give your home -- new or old -- the once over.

A change in the formula designed to remove the human health risk from pressure-treated wood appears to have created a Catch-22. The new formula puts the structural integrity of your home at risk.

To help keep pressure treated wood from rotting, old additives contained arsenic. After the industry voluntarily bowed to pressure from health and safety officials, new preservatives introduced this year most commonly include applications of ammoniacal copper quat, or "ACQ", copper azole and borate.

Wood- and metal-fastener and connector industry tests have revealed that the new preservatives are more corrosive to metal.

That's of particular concern in hurricane, earthquake and other regions where a home's structural integrity is paramount. The impact corroding connectors can have on both the safety and value of any home is just as paramount.

Pressure-treated wood has long been commonly used to provide a base or sill plate for a home's framing. The framing is attached to the base with metal connectors and fasteners. Pressure-treated wood products are also used in many outdoor applications, including children's play structures, decks, walkways and fences.

The product is also readily available to inexperienced do-it-yourself home owners who purchase supplies at Home Depot, Lowe's and other construction materials stores.

"CPSC is recommending consumers use stainless-steel brackets and fasteners in conjunction with ACQ-treated lumber," said Scott Wilson a commission spokesman.

The CPSC is considering further study based on the further tests from the connector industry and Contra Costa County (CA) consumer fraud inspector Ted Todd who works in the District Attorney's office there.

Todd looked into the issue after his uncle told him that galvanized hangers used in his new pressure-treated wood deck revealed corrosion -- within a month. His uncle lives in a humid region -- along the shores of the Umpqua River in Oregon about 30 miles from the coast.

High humidity can hasten corrosion on all kinds of metal fasteners -- screws, nails, connectors, joist hangers, etc. -- used to secure pressure-treated wood with the new preservatives, experts say.

Experts also say well-coated galvanized metals, including zinc coated products give greater protection than uncoated metals, but stainless steel is best used with the new engineered wood products because stainless doesn't corrode.

Both California's Housing and Community Development Department and the state's home building trade group, the California Building Industry Association are investigating the matter.

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