llature & technology keep wood avaluable building material

By Huck DeVenzio

demands on forests and transportation. The species of trees used for treated wood are common, plentiful, rapidly replenished, and grown on managed timberlands.

Presewative Treatments

Preservative-treated wood has been used for decades in homes-for decks, walkways, retaining walls, docks, fences, gazebos, benches, sill plate, and many other applications.

Wood treated with either copper azole or alkaline copper quaternary is used for common dimension lumber. These are the types of treated wood found in lumberyards and home centers.

Borates are effective and economical in applications not exposed to water, such as sill plate. Borate-treated wood is not suitable for outdoor use.

IOES a product that was used in l-fprehistoric shelters have a place in laser-protected, voice-activated, wifi, high-def, low-flush residences?

In the case of wood, it not only has a place but it provides aesthetic, environmental, and economic advantages. And, through modern treatment technology, wood offers additional features to homeowners while opening new applications for builders.

People like the natural appearance of wood, it is readily available, it can be installed and modified with common tools and skills, and it is often less expensive than other materials.

From an environmental perspective, you don't get much greener than wood. Besides its obvious renewability, wood requires less energy to produce than is needed for comparable building products. As a fan of wood explained, "It's produced by solar energy." Wood products sequester carbon and growing forests absorb carbon dioxide, so wood reduces greenhouse gases. It also has exemplary insulation value - thermal, electrical and acoustic.

"Interest in green building products is increasing among our members," said Angie Maxwell, department manager at ENAP, Inc., a co-op of pro dealers that recently formed a green committee to pull together information on building products. "Wood has long been recognized as a sustainable product."

Treatment processes - pressuretreatments and surface coatings-add to wood's sustainability. By enabling it to withstand wood-destroying organisms, proper treatment extends the service life of wood and reduces

Copper azole, alkaline copper quaternary, and borates are likely to remain practical preservatives for years to come, but new options are being introduced. Most notable are non-metallic preservatives that do not rely on copper but on carbon-based ingredients.

According to Jesse Peterson, Peterson Wood Treating, Superior, Wi., "Our customers are excited about a new non-metallic product called Wolmanized Lr Outdoor wood for out-of-ground applications, such as decking, rails, fence boards, and exterior trim. The absence of copper eliminates galvanic corrosion of steel hardware and aluminum flashing, and it allows for painting without conflict from the color of the preservative."

Some preserved wood contains builrin water repellent, a feature that is expected to become more common because it minimizes warping and dimensional change that occur in typical wood products.

Despite current economic conditions and the introduction of artificial wood products, Beth Taylor, a lumber trader at Ace Hardware's corporate office, reported that treated wood sales to Ace stores have increased. "We're up about 97o over last year. Our members have become more comfortable with the new preservatives, but they want wood that is associated with a beneficial program."

Fire Retardance

Fire retardant treated (FRT) wood has been used for decades, mandated by many building codes attempting to limit the spread of fire and reduce smoke generation in commercial buildings and multi-family housing. It is also appropriate for single-family homes. Typical applications include framing, trusses, roof sheathing, blocking, and shelving.

Some FRT wood boasts other sales points. Ken Panitt, Cox Industries, Orangeburg, S.C., said, "On top of its fire retardance, the Dricon brand of FRT wood has protection against termites and fungal decay. With this framing, building owners get a benefit even if a fire never occurs, as they hope will be the case."

The majority of sales of FRT wood are for interior, weather-protected uses, but there are exterior types that perform successfully in exposed applications, such as decks, balconies, covered walkways, and stairways.

Building codes are drawing attention to these products as more homes are built in crowded urban areas and in wildland areas remote from fire protection services.

Itlold Resistance

Of high current interest is mold prevention. Building occupants have health concems about mold, and contractors worry about mold liability. "Mold is a major issue in my area, Mississippi," according to Bryan Johnson, regional manager at Nationwide Custom Homes. "We need more products that prevent mold."

With such concerns in mind, manufacturers of wood treatments have introduced mold-inhibiting coatings for framing lumber, trusses, and engineered wood products. The best of these are applied at central locations where the coverage can be controlled and quality monitored, rather than being applied at eachjobsite.

Buyers should look for brands that are reliably certified for low chemical emissions; it does not make sense to trade a potential mold problem for a potential air quality problem.

Future for Treated Wood

Treated wood will remain a significant building product for the foreseeable future-the attributes of treated wood are too compelling to be ignored by builders and owners-although the portfolio of treatments will likely change, and probably grow.

Scientists may find a treatment able to protect wood against termttes and fungal decay and fire and mold, both indoors and out, but immediate attention is focused on treatments that are more convenient or less expensive for specific niches. The development of carbon-based preservatives and moldresistant coatings are recent examples.

- Huck DeVenzio is manager of product information at Arch Wood Protection, manufacturer of wood treatments and licensor of the Wolmanized brand of pressure-treated wood. He has written numerous published articles on wood preservation and enthusiastically promotes the environmental benefits of wood.