'prourlr Solutio

for manufacturers, distribxxtors, dealers, builders and homeowners

rnHE lumber industry appears to I. have a giant. new problem: mold. Yet, mold on lumber is not new: it was just never before viewed as a real problem. It was seen as a surface blemish. since the lumber was not affected structurally and would be used as framing, hidden inside a home's walls.

The difference now are growing concerns that the mold could be "toxic," presenting a health hazard to residents living inside fungi-framed homes. Although little scientific evidence exists to back the claim, the mere possibility that millions of homes could be toxin traps is enough to send trial lawyers salivating. Mold. like all fungi, requires warmth, oxygen and moisture to grow. While it is typically difficult to control temperature and oxygen for wood products, each member of the supply chain should be vigilant in minimizing the moisture.

As provided by the Southern Pine Council, the Western Wood Products Association and APA-The Engineered Wood Association, here are segmentspecific ways for you can do your part-and to pass along to your suppliers and customers:

Proper Stora$e Prevents Mold

Given the importance of controlling moislure in preventing mold, proper lumber stofage is essential. Western Wood Products Association suggests:

For green lumber,

Move inventory quickly using the "first in, first out" rule.

Sticker green lumber to allow air circulation il wood is to be stored lor a long period. Place cover boards, extending beyond the ends of the stack, on the top package of lumber to protect the wood from the sun.

Do nol store lumber near standing water;ensure the storage area has good drainage.

Raise stacks of lumber at least 12" to 18" off the ground to allow cool, moist air to move downward and awav from the lumber.

For dry lumber,

Open or closed storage sheds are preferable io outside storage. lf stored outdoors, cover dry lumber with tarpaulins, canvas or paper wrapping. . Repair any tears in paper wrapping immediately.

Store high-grade dry ilems, such as shop, moulding and millwork, in a closed, heated shed that has a clean, paved floor.

Solutions For Manufacturers

. Mold requires a moisture content of at least 2O% to survive on wood. Ensure seasoned dimension lumber is properly dried to a moisture content of 19Vo or less and properly grademarked to identify it as such. Building codes require all structural framing lumber be dried to a maximum l9%o MC before enclosure.

. Consider kiln drying instead of air drying. In addition to reducing stain, mold and insects, kiln drying also produces a more quickly, consistently, evenly dried product.

. Correctly bind, handle and store lumber at the mill site. (See tips at lower left)

. If the purchaser will pay for it, properly wrap the lumber and cover the shipment with a tarp during transport.

. Also at the purchaser's request, add a mold inhibitor, particularly for green lumber. Anti-stain treatments include NP-1. Double Diamond and Diamond Brite from Kop-Coat, Britewood from Contechem Inc., and Mycostat from Diacon Technologies. These fungicides are applied by dipping entire bundles of lumber into a treatment solution or by spraying all four surfaces of individual boards. The chemicals are designed to provide a microscopic barrier against fungal attack that lasts for three to six months, depending on the chemical, the concentration used. the wood species and the climatic conditions. They are not designed for long-term protection of the wood.

Solutions nor Distributors & Dealers

. Wrapping options are chosen at the purchaser's discretion. The purchaser may choose not to wrap the lumber, or may choose what is usually a plastic or paper wrap that either covers the entire lumber pack (six sides) or a "shed" wrap over the top and sides.

. Shipping method is also a purchaser choice. The purchaser may choose to ship the lumber on an open "chain car" flatbed, or request that the load be covered with a tarp.

Check the condition of the lumber immediately upon delivery to the receiving facility.

Correctly handle and store lumber at the distribution site. (See tips on previous page)

. Storage time should be kept to a minimum in order to reduce exposure to moisture and the elements.

Each member of the

supply chain should be vigilant in minimizing the moisture.

Solutions For Builders

Check the condition of the lumber immediately upon delivery to the job site.

. Once on site, store lumber in an orderly fashion and protect it from moisture. Lumber packs need to be properly bunked underneath (4x4s are recommended) to separate the material from ground contact. Keep lumber covered with a tarp or other vapor-permeable cover.

. Practice good housekeeping and segregate scraps from the lumber storage area. Scraps scattered about on moist ground is food for mold.

Once the builder is sure that all framing lumber is dried to a moisture content of l97o or less, the structure should be enclosed as soon as possible. Purchase of a moisture meter might be a good investment.

. Use proper construction techniques, including the correct use of flashing and weather-resistive baniers.

Solutions For Ilorneowners

. Grade and landscape lots and

ELIMINATING MOLD through better building practices was one of the aims of the Build a Better Home demonstration house in Madison, Wi. APA, the Southern Pine Council and the install downspouts and splash pads so water drains away from the foundation.

Repair cracks in foundations, flashing around doors and windows, plumbing.

Do not block vents in a crawlspace foundation, weep holes in brick veneer walls, attic turbines, or roof vents. Keep roof valleys and rain gutters free of leaves and other debris.

. Install adequate insulation in the exterior walls.

Fix plumbing leaks immediately and properly insulate pipes and ductwork.

Vent moisture-laden air from the clothes dryer, bathroom and kitchen to the outdoors, never to an attic or crawlspace.

. Take notice of musty odors in the home because they indicate the presence of mold. Look for visible signs of mold and abate the moisture source.

. Watch for condensation and wet spots and eliminate sources of moisture.

. Keep the home's relative humidity low.

. Clean and dry any wet or damp areas within 48 hours.

Mold can surface at any point during distribution and construction. Protecting lumber from moisture to prevent its growth requires vigilance and teamwork by all parties in the chain of custody.

Blue Stain Is Not Mold

What many people commonly identify on lumber as mold is actually blue stain. Blue stain, or sap stain, is not mold. lt is a bluish or grayish black discoloration of the sapwood caused by the growth of certain dark-colored fungi on the surface and interior of the wood. Blue stain can occur under the same conditions that favor the growth of other fungi.

With some molds and lesser fungus stains, there is no clear-cut way to differentiate between the two. In general, however, the dilference between molding and staining is made primarily on the basis of the depth of discoloration. Unlike mold fungus, typical sap stain or blue stain fungus penetrates deeply into the sapwood and cannot be removed by surfacing or chemicalcleaners.

Stain is an appearance characteristic only and is allowed in varying degrees in all lumber grades. lt does not affecl lumber strength or utility, nor does it pose any health risk. Soulhern Pine Inspection Bureau's grading rules permit stain and discoloration due to exposure to the elements on southern pine lumber.

IESPITE an ongoing transition to I-la younger resource base, the major manufacturers of redwood lumber reamain optimistic about the 2003 selling year.

No major redwood manufacturer has undergone as many changes of late as The Pacific Lumber Co., Scotia, Ca. Kevin Paldino, director of sales and marketing, noted, "There are still a lot of misperceptions out there about the redwood industry and Palco. Redwood is affordable and available, and we are working toward what we believe is a very bright future.