Lumber quality not declining

/\hanges in the wood products

\lindustry have given rise 3o 6iticism that lumber products have declined in quality. But like beauty, quality is often in the eye of the beholder and a closer look at lumbs pr,o&rcts today shows while ttey may lod diff€rent, they perfcm as well, if notbefier, than thoae of the pasr

Too often, comm€nts abort qulity ignore how and why lumber is graded" Lumber g[ading nrles are a set of criteria which define how various lumber characteristics, such as wane or lnots, will affect the srucural performance of dimension lunber and the aestbetic value of appearance grades. These characteristics are det€rmined in lrge part' W the natural variations ln each tree from which lumberis cut.

Since the late 1960s, lumber grades and the national grading system have operated under p,rocedures outlined in Voluntary Product Standard 20-94, publisbed by the American Lumber Standard Committee (ALSC). For nearly a qurter century, the sizes, grades and teirninology detailed in this standard have remained virtually unchanged. Lumber is graded today by standards which have be€n in place fc two and ahalf &cades.

Knots andwane are two oommonly cited lumber quality problems. However, these two characteristics cannot be clanged in the raw naterial - unless someone invents a square tnee with no branches. So, structural lumber grades cmsider how the combination of lnots, wane and other ebments affect the srength of the piece. By focusing on how characteristics affect the final end use of the prcduct lumber grades accommodate changes in the size and type of log available for processing.

In recent years, the mix of logs processed by sawmills has changed significantly. The legal gridlock on public forasts and a general shift away from old growth has led to smaller, second and third grow6 timber as tbe chief resouroe fs1 mills. This affects the variety of ltmber gfades that can be cut from a log and the extent to wbich non-limiting characteristics appea within a grade.

By Robert IL EUr Prcsllent Westem Wod Pr,oducts Associatbn

Large diameter logs from older rees t€nd to yi€ld mue cleu lmber thm smaller sizes. At the sme time the big bgs have lrger loots c otbr undesirable characteristics, which reduce the grade. While more clear lumber is found in old growth timb€r, ths€ is also a higber vohrne of lower grade materials.

Second growth timbernay cmtain mae lnots. It yblds less cba, wane. free lumber and a higber percentage of middle-grade material. This has fostered a perception that it is of lower quality. But tnots arc small€r and tigbter, and the slope of $ain is often better for some carcgories of stnrcUral lumber. Smalhr logs pro due a larger shre of strnc{nal light framing grades such as Select StrucffalNo. 1andNo.2.

The effects of more secmd gFm,th timber can be seen in WWPA grade fecovery surveys. Dimension, or structural lunber, traditionally accq|nts for nerly half of tbe West's lumber production and includqs the grades most commonly cited as having qulity p,roblems. In 197e aborlt 70% of dimension lumber was graded as Standard and Beuer, q No. 2 md Beuer. As mue s€cond growth limber moved to 6e miil$ that percentage rose. By 1992, these grades aocorrnt€d fc more the 80% of poduction - providing the market with the produce mt in demand At Se same time, the volume of high grade, cler material has declin€d, as has tbe amount of lower grades.

Grrade recovery is not the only area where dimension production has changed. Higher volumes of mseasoned, of green, lumber are used today. Twenty yeils ago, N% of. all

Story at a Glance

Westem dimensio hmber w6 ge€o, with moisure omEnt above 19%. By lW2"smre4H;% was green.

Green lumber requires different sttrage, bmdfrrg and installatin tecb' niques tbm &y lmbcr. Witbot pe cautions, lumber can dry unevenly, causing warp, twists and splis. Improper storage can lead to mold, mildew and sains. In sme instanes, tbase problems have prompted ques" tims about the quality of the lumber. But proper stmage and handting can minimize perceivod quality problems in green hmber.

Lumber customefs today have a vast array of grades 30 select ftoD wbn chocing apro&n Those wb want a strucnral product with higD afedae qmlitics cm fid tbe hber to meetthcetrcds. But, Scy ncod to udetstaul tht just because it loots good doesnt mem it will perfum any be0€r. AnG grv€n 6e limited upply of such products, the price will tre higb€r thrn tbat of ol[er grdes whid may notlookas goo( htr will perform as required.

lVith today's economic rcalities, it is more importmt tbm ever to choose the proper grade of lumber for the intended rylication. The key !o making tbe prq€r sebctim lies in fmowing whfoS grdes arc best suited for tbe inrnded use.

Even with the extensive quality conEol system in place for lumber, th€re is an occasioal sinndm when a lumber shif€nt is otrara&. SbouH reasonable questions aise about quality, options re arailable to tboce buying WWPA grdemdfted lumber.

Often a call to the supplier or WWPA can resolve the proble,m. In instances where an objective ass€ssm€ntis desfu€d, aprcfessimal WWPA lumb€r inspector co reimpoct lumber to d€termine if it meets surted standads. If i1 falls bebw roqufued standards, the customer may refuse to acaept it and tbe mill pals for reinryection costs.

Over tbe past decade, WWPA has seen a steady decline in rcinspectim rpquasts, rcflecting improved relatins benveen mills and q$tmers, a beuer undemtanding of lumber grading sandards in tbe matet ild 6e indrstry's cqnmim€nt to quality prodrrcts.