No one prefers green lumber. Its higher shipping weight, poorer nail-holding power, and shrinkage after fabrication are well known, but the present pressure for deliveries results in much of it being accepted. Another major objection to lumber shipped green is that is may be damaged bu wood-decaying fungi, either in...
The rat caused by Pozia incrassata (Berk, and Curt.) Burt (sometimes erroneously called "dry rot") in individual cases is the most destructive of the building decays in the warm coastal portions of the United States and the South. The fungus usually attacks rapidly and may cause damage necessitating extensive repairs...
The successful air seasoning of lumber and other wood products depends largely upon the correct handling of stock from the time it leaves the saw until it reaches a moisture content suitable for use.
The following points summarize the general rules for laying out the yard end piles, for piling,...
Published February 1992. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published September 1995. A more recent reprint exists. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Published September 1995. Reviewed August 2016. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Volatile organic emissions (VOCs) from the kiln drying
of lumber are of concern to government, research agencies,
and the forest products industry. In the Pacific
Northwest, neither the quantity of VOC emissions from kilns
drying Douglas-fir is available, nor the effects of drying
schedule and lumber-related characteristics on the
emissions....
As lumber producers are faced with a diminished and increasingly expensive raw
material, the need to maximize resource recovery will increase. Trim-ends (particularly
from waned boards) often contain some of the highest quality wood in any given log
and lack functionality only in length. This waste, traditionally chipped for pulp,...
Wood components, usually assembled in green or semi-dry condition,
dry during the initial service life. To evaluate the effect
of such drying on joint stiffness and damping, cyclic-load tests
were conducted on single-nail joints of wood and plywood that had
been exposed to drying cycles. Additional effects studied were the...
New technology allows the production of thinner kiln sticks
manufactured of phenolic resin impregnated paper which are both
structurally and economically realistic. This project tested the effects
of kiln stick thicknesses on dry kiln air circulation and on
lumber drying degrade.
Three variables, stick thickness (3/4, 9/16, 7/16 and 1/4...
Lumber drying accounts for about 70 percent of sawmill energy
requirements. Significant recovery of energy used to dry lumber
would result in significant energy recovery for the mill. This is
desirable because of today's high cost of energy. The objective of
this study was to recover some of the energy...
To test the effects of kiln-drying on strength properties of Douglas fir and western hemlock, temperatures to 230 F, conditions for equilibrium moisture contents of 6 percent and 12 percent, and prolonged heating were investigated.
Prolonged heating and choice of conditions for 6 percent or 12 percent equilibrium moisture content...
Forced-air drying of lumber is economically feasible as an aid to sawmills without dry kilns. Reduced cost of shipping more than offsets cost of drying with forced circulation of air. Investment in equipment is small.
In the Willamette Valley, forced-air drying probably can be accomplished successfully throughout the year. High...
Checking was influenced b drying conditions. This influence was greatest before average moisture content reached 20 per cent, but tension in surface layers caused checking even below this point.
Neither high initial dry-bulb temperature nor initial conditions of high equilibrium moisture content were conducive to checking.
High temperature and high...
The vapor-drying process is described briefly and its present status in industry is discussed. Fairly extensive data on the vapor drying of 1-, 2-, and 4-inch Douglas-fir and 2-inch western hemlock lumber are presented. Exploratory work on the vapor drying of redwood, Pacific madrone, red alder and ponderosa pine is...
The increasing volume of young-growth Douglas-fir timber cut in the Pacific Northwest emphasizes the need for more knowledge on the characteristics of lumber sawed from these trees.
The study described here was initiated to learn the extent arid causes of degrade resulting from kiln-drying young-growth Douglas-fir dimension lumber. At the...
Oregon white oak, Quercus garryana Dougl., could have greater commercial use, but information on its drying properties is lacking. All oaks are difficult to dry, and the initial kiln conditions are important to prevent excessive surface checking and honeycombing. This study illustrated that a maximum dry-bulb temperature of 110 F...
Large inelastic strain occurs inside a piece of lumber during drying. The strain consists of several components such as elastic, plastic, creep, shrinkage and mechano-sorptive effect. The mechanical behavior of the whole board during drying is determined by the behavior of individual strain components and their interactions. Whereas limited investigations...
