FIJ lumber sports new marks for heat resistance ,,I3,.. STUD M

NEW HRA mark now appears on most F/J lumber produced in the West, indicating it has been joined with heat-resistant adhesive.

Dfllt"l.1:.:::Hi,"Jff :f '#i,t

are seeing new marks on the gradestamps added this past summer to products joined with approved heat- resistant adhesives.

Most of the fingerjointed lumber produced in the West carries the new HRA mark, indicating the lumber has been joined with heat-resistant adhesive. The HRA designation is incorporated with the other information on the gradestamp.

HRA-marked fingerjointed lumber can be used in assemblies that must have a fire rating under U.S. building codes. Typically, one-hour fire rating is required for multistory/multifamily structures between living units. Detached single-family homes under cunent building codes do not require one-hour rated assemblies.

This spring, the American Lumber

Standard Committee established a new policy for HRA fingerjointed lumber and adopted procedures to qualify adhesives as heat resistant. Adhesive makers have conducted fire tests and submitted results for qualification.

So far, eight adhesives have been approved as heat resistant. Western Wood Products Association, which provides grading services for more fingerjointed lumber than any western agency, evaluated and earned ALS approval for seven of the eight adhesives.

Lumber joined with adhesives that have not been approved as heat resistant can be marked as Non-HRA. Presently, fingerjointed lumber with no HRA mark will be considered the same as Non-HRA market lumber and should not be used in fire-rated assemblies.

WWPA has prepared a Fast Facts sheet on HRA fingerjointed lumber, which includes facsimiles of the new gradestamps, background on the testing for heat-resistant adhesives, and approved uses for such lumber.

Fast Facts can be downloaded from www.wwpa.org.

m[*rL__ryFASIffiAJ

Eall Billy Sunn (509) 422-7033 or Terry Johnson (509) 422-7023 Fax 509-422-7034

Company Micronizes Copper Azole

PhibroWood,LLC, Ridgefield Park, N.J., has developed reportedly the first micronized copper azole wood preservative, Sustain 20T.

Micronizing the copper in solid particles produces a less corrosive chemical, as proven by micronized ACQ products introduced by PhibroWood last year and by Osmose in late 2006. PhibroWood has even higher hopes for SustainT, because of its low retention levels (0.07 pcf for aboveground use and 0.16 pcf for ground contact use) and more economical concentrated form.

The new preservative has been ICC reviewed. PhibroWood is producing SustainT at its plant in Sumter, S.C., which will continue producing PhibroWood-CQ micronized ACQ along with its facility in Joliet, Il.

Early this year, PhibroWood expects to begin offering Sustain 20CQ, a micronized copper carboquat system for wood treaters looking to employ copper quarternary systems and micronized copper in a shared cylinder.

Setect The Right Trim Board

(Continued from page 17) hard to get at the moment, but lots of built-in decay resistance and a proven track record. What about "other?" Well, from China there's Paulownia and C. lanceolata. The latter is the one that has been attacked lately for being "not really cedar or fir." That's true, but on the other hand, the Confucian temples I saw in China were built 900 years ago with the stuff. My decay-resistance meter doesn't go that high. I'll have to call Spinal Tap and see if they have a meter that goes up "to eleven."

Paulownia is a stable board with some decay resistance, though it's very soft. C. lanceolata is difficult to get in a clear, but the knots have not caused a problem in our experience.

I could go on about substrates for days, but let's move on to coating systems. The typical coating system for most of the last 20 years has been oil-based primer. The market has taught us in the last couple of years, with the help of PVC, that people are willing to pay more for a better value. The answer has been to use a primer and topcoat or, at least, more than one coat to create a smoother, more opaque finish that lasts longer in the field. Some coating systems are even boasting zero emissions, a dramatic advancement for the industry. Latex coatings applied directly over raw substrate tend to swell the grain. Oil coatings allow the grain to remain flat. Some oil coatings are capable of wood fiber encapsulation resulting in better water repellency.

Getting the coating right for exterior trim takes some research. For example, with the success of Gesso for interior applications, some manufacturers have tried to duplicate the coating for exterior. One product from China has a very smooth finish, but when I placed it outside it cracked within two days. Look carefully at how these products are tested. The wrong exterior coating is a big potential liability.

For sourcing, we've seen quite a shift in the last ten years from domestic to Europe to South America and New Zealand to more recently, China. This has been driven as much by manufacturing investment as it has by currency exchange rates. China has the lowest labor cost, but keep an eye on Russia. They still have the most trees by far, at almost 5OVo of the standing timber in the world.

One unique spruce trimboard we saw from Germany had to switch manufacturing to the Baltic states about five years ago as the dollar decreased in value. Now, we see a huge increase in exports to Europe and a dramatic decrease in imported spruce and pine. South America looked like a great altemative, but some price pressure might loom as the dollar falls against the peso and the real. China sourcing will likely be the next wave for new trim board species. Wages in China are rising rapidly as its economy grows and the country learns there's a cost to getting it right. Ordering wood from China has a big impact on turns as the wood stays on the water for several weeks.

This might seem more like an introduction to wood trim boards than a big help in making your selection easier. Sometimes knowing the breadth of the problem helps to break it down. Plus, you can always call me. I'm usually just sitting around watching paint dry.

- Dennis Connelly is co-creator of Ze-VO Technology, c.o.o. of PrimeTECH, and a member of the Forest Products Lab Joint Coatings Forest Products Committee. He can be reached at dconnelly @ zev ote chnolo gy. c om.