Tleated redwood?

I T SOME time in the near future, Fl dealers may be stocking sapwood grades of redwood that have even greater durability than all heart redwood. Preservative pressure treatment has the potential of creating a deck material with exceptional physical characteristics from the most common grades of redwood.

"Several dealers have expressed interest in treated redwood," said Tom Gardiner, sales manager of LouisianaPacific's treating operation in Ukiah, Ca. "They like the idea of extending the life of sapwood grades while retaining the workability and dimensional stability for which redwood is known. So far, though, there has not been an economic incentive for making treated redwood decking."

Thattime may be coming, however, as supplies of heart redwood diminish. Notechnical obstacles stand inthe way.

"Sap redwood can be treated effectively with CCA (chromated copper arsenate)," Gardinersaid. "The American Wood Preseryers' Association lists redwood for a variety of applications. We regularly treat redwood for industrial uses, especially cooling towers."

Redwood has been used for decades in cooling towers to avoid the corrosion that damages metals. Originally this redwood was untreated. Now, according to John Condon ofEcodyne, a producer of cooling towers, the Cooling Tower Institute requires that all wood within the tower be pressure treated.

Tests on treated redwood lumber have been conducted by Hickson Corporation, the manufacturer of Wolman CCA. They found problenr are aesthetic, not technical.

Dr. Craig Mclntyre, manager of R & D at Hickson, said, "CCA treatment adds decades to the life of sap redwood. However, in our initial trials, heartwood turned a dark color while sapwood areas remained light. We don't feel consumers would accept this variation.

Story at a Glance

Treated redwood is consideredaviableproduct. CCA extends life of sapwood, retains workability and dimensional stability ... no economic incentive at present, but environmental concerns may change its commerical potential.

"Then we introduced a color additive into the CCA solution and treated more samples. The result was lumber with a reddish brown color and greater consistency between heartwood and sapwood. This wood is attractive and has commercial potential."

Environmental concerns may offer dealers anotherselling point. The longer life of treated redwood will help conserve redwood resources.