Western Woods Region
| Of the West's approximately 136 million
acres of forested land, there are nearly 40 million acres of
commercial timberland* and nearly 50 million acres of forested
land, including some 13 million acres of designated "old
growth," permanently set aside in parks, scenic reserves,
wilderness areas, habitat reserves and research areas -- forever
protected from harvesting. In addition, as of 1996, more than
80 percent of the forested area in the region's National Forests
has been withdrawn from timber harvesting due to legislative,
administrative, or judicial actions as even more progressive
ecosystem management plans are implemented. |
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(*Timberland is forested
area producing or capable of producing crops of industrial
wood and not withdrawn from timber utilization by statute
or administrative regulation. Any reference to standing volumes
of sawtimber or acres of multiple-use timberland available
for timber products in this text do not include any of the
forested land that is permanently set aside, protected from
harvesting.)
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The Western Woods region is subjected to some of the
toughest forest practice regulations in existence anywhere. In Western
forests, growth exceeds harvest by more than 35 percent overall
and by more than 50 percent in some areas. Refer to the section
on "Environmental Performance" for additional information.
Hem-Fir species group
In the Western Woods region, the 12 contiguous Western
states plus Alaska, there are approximately 20 commercially important
species well suited to softwood lumber production. While each has
unique characteristics, physical and mechanical working properties,
making it appropriate for specific applications, these Western softwood
species are grouped into six primary combinations. These combinations
simplify production, inventories and distribution, and facilitate
engineering and product specification for design.
Hem-Fir is a species combination of Western Hemlock
(Tsuga heterophylla) and five of the True Firs: California Red Fir
(Abies magnifica), Grand Fir (Abies grandis), Noble Fir (Abies procera),
Pacific Silver Fir (Abies amabilis), and White Fir (Abies concolor).
While Western Hemlock and the True Firs are sometimes marketed separately
in products graded for appearance, these species share similar design
values making products graded for structural applications interchangeable.
The Hem-Fir species combination is one of the most
important in the Western region, second only to the Douglas Fir-Larch
species group in terms of abundance, production volumes, strength,
and versatility in end use.
Range, growth habits & production
 In
the West, the species in the Hem-Fir group commonly grow in intermingled
stands along the Pacific Coast, from the Kenai Peninsula in Alaska
to northwestern California. They also grow inland in a narrow, scattered
pattern along the U.S.-Canadian border and then spread out fanlike
to climb the mountain slopes of northeastern Washington, northern
Idaho, northwestern Montana, and through the Selkirk Mountains of
southeastern British Columbia. The largest stands are found in the
humid, coastal mountains and on the western slopes of the Cascade
Range in Oregon, Washington, British Columbia and Alaska. They thrive
in this mild and humid climate, where frequent fogs and rain provide
moisture during the growing season.
Western Hemlock, also known as West Coast Hemlock
or Pacific Hemlock, was discovered by botanist Stephen L. Endlicher
in 1847. He christened hemlock "tsuga." In Japanese, tsuga
means "yew-leaved," referring to its short, flat -- and
contrary to legend -- non-poisonous needles. Among the True Firs,
White Fir was first discovered along the Columbia River in 1831
by Scottish botanist David Douglas. Douglas Fir (Pseudotsuga menziesii),
which is not a fir at all but a distinct species, was named after
this famous botanist.
Western Hemlock can be easily distinguished from other
conifers in Western forests by its downward sweeping branches and
drooping top. The needles have rounded tips and grow from the sides
of the stems in pairs. Seed-bearing brown cones sprout at the ends
of branch shoots. Like Douglas Fir, the lower branches of Western
Hemlock die and fall away because of competition for sunlight. Thus,
as the tree grows, it "prunes" itself and develops clear
trunks up to three-quarters of its height. This natural characteristic
is highly desirable in softwoods, as it leads to increased volumes
of clear lumber in large logs.
Abundant in managed forests, it is estimated there
are more than 380 billion board feet of Hem-Fir sawtimber on the
managed timberlands of the Western region. Second only to Douglas
Fir-Larch, Hem-Fir accounts for 28 percent of Western lumber production
annually. This important species combination is nearly as versatile
as Douglas Fir-Larch (which accounts for half of total Western production
volume), lending itself to a variety of products.
Characteristics & best uses
In its unique way, Hem-Fir is a perfect combination
of strength and extraordinary beauty and is quite literally one
of the most handsome, elegant and versatile softwood species combinations
on the market today.
Hem-Fir lumber is light and bright in color, varying
from a creamy, nearly-white to a light, straw-brown color. It can
be as light or lighter in color than some of the Western pines and
is often considered, by those seeking a strong wood with a very
light color, as the most desirable of the Western softwoods. Sometimes
Western Hemlock may have a slight lavender cast, especially around
the knots and in the transition area between the spring and summerwood
growth rings. Attractive, delicate, dark grey or black streaks may
be apparent in the wood. There is little variation in color between
the heartwood and sapwood.
Hem-Fir lumber products are available in structural,
appearance and remanufacturing grades. In strength properties, Western
Hem-Fir is slightly below the Douglas Fir-Larch species combination,
and above both the Douglas Fir-South and Spruce-Pine-Fir (South)
species combinations. Hem-Fir is useful for a multitude of general-purpose
framing applications and is capable of meeting the span requirements
of many installations.
In the clear and nearly clear appearance grades, Hem-Fir
"Finish & Select" products are fine grained and even
textured, lending formality to wood paneling, cabinets and trim.
Hem-Fir "Factory & Shop" grade products are remanufactured
into handsome solid wood doors, louvers, shutters, moulding, case
goods, furniture and more. Limited volumes of knotty, board products
are available in Hem-Fir and these are graded primarily to the West
Coast Lumber Inspection Bureau's "Alternate Board" grade
rules, and to some extent to WWPA's rules for the "Common"
grades. Lower-grade knotty products are useful for those utilitarian
applications in construction where economy governs.
Preservative pressure-treated Hem-Fir products are
both visually appealing and strong, and in comparison to the naturally
durable Western cedars and redwoods, among the more economical species
considerations for decks and other outdoor amenities. Among the
Western species, Hem-Fir is a preferred species group for preservative
pressure treating.
Grading
Recognized worldwide as a symbol of integrity, the
Western Wood Products Association's grade stamp is a lumber buyer's
guide to lumber satisfaction. This mark represents each WWPA Member
mill's commitment to consistently deliver a product which meets
uniform quality standards, whether the lumber is intended for structural
or appearance purposes.
| Hem-Fir products carrying the WWPA
certification mark are backed by the Association's quality control
and inspection services, technical and field services, and the
design and engineering data necessary to use Western lumber
products in construction. WWPA is the only Western lumber association
that provides this level of product support to the buyers of
its Member companies' grademarked lumber. |
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Lumber grades are divided into three basic categories:
Moisture content, seasoning & marketplace preferences
"Green" lumber is unseasoned lumber. It
is gradestamped as "S-GRN" and has a moisture content
(MC) level above 19 percent at the time of surfacing. The same design values
apply to both S-GRN (unseasoned) and dry lumber. However, the term
"dry" can be confusing in lumber terminology.
In general, "DRY" indicates a product was
either air-seasoned or kiln-dried to 19 percent or less moisture
content at the time of surfacing. S-DRY can mean kiln dried or air
seasoned, while KD specifically means kiln dried. The moisture content
level of DRY lumber is further qualified depending on the general
classification (i.e. structural- or appearance-grade categories),
the grading rules for specific grades (e.g. MC for "Finish
& Select" grades is specifically qualified), and/or by
the specific terms of buyer/seller agreements.
In structural grades, DRY indicates a product was
either air- or kiln-dried to 19 percent or less MC at the time of
surfacing. It will be stamped S-DRY or, if kiln dried, KD or KD-HT.
Any lumber surfaced at a moisture content level of 15 percent or
less may be stamped MC15, or if kiln dried, KD15.
Historical practices and regional market preferences
influence the availability of structural framing lumber at certain
moisture content levels. Over time, certain regions evolved as "green
markets," with a preference for S-GRN products such as Douglas
Fir-Larch framing lumber, while other areas evolved as "dry
markets" for such products as S-DRY or KD Hem-Fir.
Historically, Hem-Fir products were shipped to inland
U.S. markets and Western lumber manufacturers dried their Hem-Fir
prior to surfacing in order to reduce its weight for overland transporting.
Over time, builders began to like these dry framing products and,
as a result, certain areas became dry markets for Hem-Fir.
Tradition continues to influence current practices
for Hem-Fir manufacturing. Approximately 80 percent of Western Hem-Fir
framing products are manufactured and shipped either S-DRY, KD or
KD-HT. Dry Hem-Fir performs well and historical production practices
have led to today's wide availability of Hem-Fir in dry STUD and
other Dimension and special Dimension lumber grades.
In appearance-grade products, the term DRY indicates
a product was either air- or kiln- dried to 19 percent or less moisture
content in the Alternate Board and Common grades. However, due to
marketplace preferences, these products are occasionally manufactured
and shipped by WWPA mills at lower moisture-content levels. If dried
to 15 percent or less moisture content, these grades can be gradestamped
(on either wide face or the ends) MC15 or KD15, as appropriate.
In the clear and nearly-clear high-end appearance-grade products,
such as the Finish & Select grades, DRY specifically means a
maximum of 15 percent moisture content.
In addition, as specified in WWPA's Western Lumber
Grading Rules, 85 percent of the items in Finish & Select
grades are shipped with a MC level of 12 percent or less. Often
the highest-quality, appearance-grade products are not gradestamped
to avoid marring the beauty of the wood. In these cases, grade and
moisture-content information is included in the written documentation
accompanying products.
For millwork, remanufacturing applications or glued
products, Hem-Fir is seasoned in temperature- and humidity-controlled
dry kilns or stickered and air dried until its moisture content
reaches the desired level for the intended purpose -- a level often
set by the buyer. Unless specified otherwise by agreement, Western
Hem-Fir production in the Factory & Shop grades is shipped at
MC15 or KD15, with 85 percent of the items at 12 percent or less
MC.
Framing products
 Since
Hem-Fir framing lumber products are nearly as strong as Douglas
Fir-Larch, they can meet many of the structural load-bearing and
load-carrying requirements of residential, light commercial and
heavy construction. With their good strength and stiffness properties,
S-DRY and KD Hem-Fir structural-grade products are well suited to
framing systems where solid-sawn, structural lumber is needed for
immediate use in an assembly of other dry framing products (I-beams,
structural-glued finger-jointed lumber, stress-rated boards, etc.).
Dry Hem-Fir framing products are subject to minimal shrinkage and
checking, and thus perform extremely well in hot, dry climates,
or in cold, low-humidity climates, and in multistory framing.
Recently, in some regions of the U.S., end users have
experienced "bouncy" floors when imported species have
been used to their maximum allowable published spans. In contrast,
published design values for all U.S. species combinations have proven
reliable in end use and U.S. species perform well to published allowable
maximum spans. Hem-Fir's modulus of elasticity (MOE or E) value,
a stiffness factor in floor systems, exceeds all other Western species
combinations except Douglas Fir-Larch, the species combination which
is held as the standard against which all other framing lumber is
measured worldwide. It is the combination of stiffness (MOE value)
and strength (Fb value) that yields a satisfactory floor system.
Hem-Fir is additionally preferred by many builders
because of its: resistance to splitting in nailing and screwing;
ability to hold nails and screws securely; ease of sawing without
splintering; ability to hold a variety of glues and adhesives; and
moderate lightness in weight. It is straight grained, stiff, strong,
easy to work and relatively free from pitch.
Dimension Lumber: The bulk of S-DRY and KD Hem-Fir
is produced in Dimension lumber sizes (2" to 4" thick
by 2" and wider). Dimension lumber Hem-Fir products include:
Structural Light Framing grades fit applications
where high design values are needed in light-framing sizes for engineered
applications, trusses, laminated products and multistory projects.
(grades include SELECT STRUCTURAL, NO. 1&BTR, NO. 1, NO. 2,
and NO. 3.) These grades may be a special order for some retail
lumber suppliers.
Light Framing grades are intended for general
framing applications such as wall framing, plates, sills, cripples,
blocking, etc. (CONSTRUCTION, STANDARD, and UTILITY).
STUD grade is intended for vertical installations
in wall systems and other applications including blocking and furring.
Structural Joists & Planks, in 2x5 through
4x18 sizes (with the majority of production in 2x6 through 4x12),
are available in SELECT STRUCTURAL, NO. 1&BTR J&P, NO. 1,
NO. 2 and NO. 3 to fit engineered applications where larger-sized
members are required.
Special Dimension: Hem-Fir products in this
category include Machine Stress-Rated (MSR) lumber for components
manufacturing and engineered applications, and structural-glued
(end- or fingerjointed) products,which are recognized by U.S. building
codes as interchangeable with solid-sawn lumber products of the
same grade, species and intended end use.
One quarter of the lumber used in components and truss
manufacturing is MSR lumber. Hem-Fir MSR products are commonly available
in several stress levels, occasionally up to 2400 Fb-2.0E. These
MSR products offer good strength-to-weight properties, recognized
plate-holding ability, exceptional stiffness and consistent availability
in a variety of lengths, widths and grades.
Hem-Fir is ideally suited for structural-glued products.
The USDA
Forest Products Laboratory rates Hem-Fir in the top group of
softwoods for ease of gluing, based on glueability under varying
conditions and with different types of adhesives. This, along with
Hem-Fir's inherent strength properties, make the species combination
a natural for end- or finger-jointed, edge- and face-glued structural
products. And because of its beauty, it's a natural for finger-jointed
millwork and mouldings, edge- and face-glued boards, and laminated
stock. These products make excellent use of short lengths, thus
increasing utilization of available timber resources. WWPA provides
testing and quality control for glued products, currently certifying
the manufacture of Hem-Fir structural-glued Dimension lumber and
board products under the following classifications: Light Framing
and Studs, Structural Light Framing, Structural Decking, Stress-Rated
Boards, and Structural Joists and Planks.
Larger sizes: The bulk of production in the larger
sizes is manufactured and shipped S-GRN. Hem-Fir products in the
5" & thicker and 5x5 & larger sizes of Beams &
Stringers and Posts & Timbers are unique products well suited
to meet specific design criteria.
(Refer to WWPA's Western Lumber
Product Use Manual for additional design information, to
the Structural-Glued and
MSR Technical Information Product Sheets for information on
these products, and to WWPA's Vol. 1 Species Book: Dimension Lumber
for color photographs of structural grades.)
Structural decking
Hem-Fir is a discerning selection for exposed ceilings
and a practical choice for roofing, flooring or subflooring. Of
the many products available in Hem-Fir, Structural Decking truly
showcases Hem-Fir's combination of strength and beauty. These products,
which are also known as "roof decking," are 2" to
4" thick by 4" & wider in width and available in two
grades: SELECTED DECKING (for fine visual aesthetics) and COMMERCIAL
DECKING (when appearance is less important).
 SELECTED
DECKING can be used so that the face, or better side, will show
the sophisticated, casual elegance of Hem-Fir in applications such
as exposed ceilings. Its moderately light weight makes it easy to
handle and install. Hem-Fir is usually run to standard decking patterns,
in nominal 2" and 3" single tongue-and-groove (T&G),
and is available with V or rounded edges. While SELECTED DECKING
is a structural-grade product, some WWPA Member mills provide a
proprietary variation of this product through buyer/seller agreement.
These proprietary products give consideration to appearance characteristics
in order to meet discriminating architectural requirements and/or
a specification for MC15 or KD15 in a 2x structural-grade product.
As with any product to be used in a T&G application, it should
be acclimated to the surrounding atmosphere prior to installation.
COMMERCIAL DECKING is ideally suited for subflooring
in both solid-sawn and structural-glued products. Because Hem-Fir
is nearly as strong as Douglas Fir-Larch in extreme fiber stress
in bending (Fb)and modulus of elasticity (E or MOE), it can meet
engineering requirements for many structural decking installations.
Some T&G decking is manufactured to pattern from NO.2 &
BTR or No.3, 2x6 or 2x8 framing lumber. These products are generally
used for concealed subfloors in deck and girder construction.
Appearance products
In products graded for appearance, wood-savvy architects
and designers often choose Hem-Fir for trim, fascia, paneling, moulding
and millwork, as well as for exposed wood ceilings. Substantial
volumes are available in the clear and nearly-clear appearance grades
and whether used extensively, such as for paneling, or in small
decorative elements, Hem-Fir boasts remarkable versatility and usefulness.
It compliments many architectural styles and design themes.
When acclimated prior to installation, MC15 or KD15
Hem-Fir products retain their shape and size without shrinking,
swelling, cupping, warping, bowing or twisting. Adding to its aesthetic
qualities, Hem-Fir, like all wood, is a very good insulating material.
It has a coefficient of heat transmission, or K value, of .89 BTU
per inch of net thickness at 12 percent moisture content, which
puts it among the best species for insulating properties. 
Interior designers often like Hem-Fir for two primary
reasons: its color and natural resistance to darkening from exposure
to light. While all wood darkens over time with exposure to sunlight,
Hem-Fir often remains true to its original, freshly-milled pastel
color.
Finish carpenters, remanufacturers and woodworkers
like Hem-Fir for other reasons. The straight grain and fine texture
sands to a silky, reflective smoothness with virtually no tendency
to split. Hem-Fir yields clean, straight edges and accurate contours
with either machine or hand tools, and can be worked easily by either.
The wood grips fasteners securely and accepts adhesives without
a problem. It readily accepts finishes, ranging from clear coatings,
transparent lacquer, varnishes, oils or wax to a full selection
of stains and bright or subdued tints or paints.
The clear and nearly-clear products dominate the
appearance grades in Hem-Fir. The highest grade categories, Finish
& Selects, may be specified in either vertical or flat grain.
If grain pattern is not specified, these grades will be shipped
as a combination of vertical and flat grain. These high-appearance
Western lumber products include Selects (B & BTR SELECT, C SELECT
and D SELECT) and Finish(SUPERIOR, PRIME, E). Such products are
recommended for interior wall and ceiling paneling, trim and cabinet
work with either natural, stain, or enamel finishes that respect
their fine appearance. These products may be wrapped at the mill
for protection in shipping and handling.
Most of the knotty fiber in Hem-Fir is generally manufactured
into structural products whenever possible. However, some knotty,
appearance-grade products are manufactured in Hem-Fir. These products
are manufactured and shipped about half and half in S-GRN and S-DRY
and are intended more for general construction applications than
fine interior installations.
For the most part, the general-purpose, knotty-appearance
grades in Hem-Fir are manufactured, by tradition, in the Alternate
Board grades of the West Coast Lumber Inspection Bureau's (WCLIB)
grading rules. These grades include SELECT MERCHANTABLE (used primarily
in housing and light construction for soffits and fascia, and occasionally
for shelving where sound, tight knots are acceptable), CONSTRUCTION
and STANDARD (for general construction purposes and serviceability
in sub-floors, roof, wall sheathing, and let-in bracing), and UTILITY
and ECONOMY (for use in applications where economy is the basic
requirement).
(Refer to WWPA's Vol. 2 Species Book: Boards and
Commons for additional information and color photographs of appearance
grades in a variety of Western softwood species.)
Paneling
The clear and nearly-clear paneling products available
in Hem-Fir give a stunning, soft glow to ceiling and wall paneling
in traditional and contemporary homes as well as a subtle, sophisticated
ambience in family and living rooms, dens, bedrooms, and kitchens.
Because Hem-Fir has a flame-spread rating of 73, it qualifies for
a Class 2 (or B) rating. Consequently, it is frequently specified
as paneling in public buildings such as theaters, shopping centers
and restaurants. Europeans have made Hem-Fir a popular choice for
paneling because of its uniform tone, luster and hardness.
Like all patterned products, solid wood paneling products
reflect the grade of their starting, appearance-grade material (as
described above), adhering to similar requirements for permissible
characteristics. In most cases, paneling products in Hem-Fir will
be run-to-pattern from the exquisitely beautiful, clear and nearly-clear
Finish & Select grades and are available in a variety of patterns.
Whereas several grades of knotty paneling products are widely available
in the Western pines, knotty grades in Hem-Fir are not commonly
remanufactured into paneling products.
(Refer to WWPA's Standard
Patterns for dimensioned profiles of run-to-pattern products
and to the TIP Sheet on Flame-Spread Ratings
for additional information.)
Factory and shop products
Lumber intended for trim and other non-structural
applications may be from the appearance category of grades, as described
earlier. Or, if intended to be run-to-pattern or further manufactured
into specialty wood products, it may be from the Factory & Shop
category of grades. These MC15 and KD15 Hem-Fir products are available
in a variety grades for such end uses as mouldings, doors, windows,
case goods, etc. This category of lumber products, which is graded
to be re-cut for the recovery of clear pieces in pre-determined
sizes, is usually available only in large volumes, mill direct to
remanufacturers.
Owing to its unique combination of attributes, Hem-Fir
is a dominant species combination for manufactured woodwork. It
is readily and accurately milled to sharp detail. Its smooth surfaces
and high dimensional stability assure continuing fine appearance
over time. Hem-Fir moldings and interior trim do not splinter, are
resistant to scuffing and the effects of use over time, and the
color tones remain light.
On the West Coast of the U.S., residential baseboard
and door-jamb mouldings are more often manufactured from Hem-Fir
than any other species. Hem-Fir mouldings come in a wide choice
of attractive patterns and varying lengths. Stair components made
from Hem-Fir are exceptionally hard wearing and will readily take
paint or stain finishes. And because it can be machined easily with
exact precision, a number of decorative items are also made from
Hem-Fir: turned and worked cornices, crown mouldings, shutters,
louvers, blinds, ornamental trim pieces, furniture and cabinets,
wine and spice racks, knife holders, serving trays, cutting boards
and more.
Treated products
Hem-Fir is readily pressure treated with preservatives.
Such products, generally in Dimension lumber grades and sizes, are
widely used for backyard outdoor decks. Treated Hem-Fir is easily
stained to resemble cedar or redwood, or it may be given a clear
protective finish to enhance its natural color. It is a preferred
Western species group for preservative pressure treating. Because
of its combination of strength properties and beauty, this species
combination is useful for both the load-bearing as well as non-structural
components of outdoor installations. It is also very abundant which
makes it more cost competitive than the naturally durable species.
With incising (small cuts are made in the surface of the wood before
treating), Hem-Fir may be treated to appropriate retention levels
for above-ground, ground-contact, or in-ground installations.
The American Wood Preservers Association (AWPA) provides
treating standards and retention levels for a number of preservative
and fire-retardant chemicals. All pressure-treated wood should bear
the mark of a quality control agency approved by the American Lumber
Standard Committee. Chemical retention is stated in terms of the
weight of the chemical retained (in pounds) per cubic foot (pcf)
of wood after treatment; the larger the number, the more chemical
retained. In general, relevant AWPA standards and retention levels
for waterborne preservatives are:
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0.25 pcf to AWPA Standard C-2 is required when
the product is used above ground;
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0.40 pcf to AWPA Standard C-2 is required if the
lumber is in contact with soil or fresh water;
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0.60 pcf to AWPA Standard C-15 is required of
the lumber is used as a permanent wood foundation.
For more information, contact the Western
Wood Preservers Institute.
WWPA Western lumber environmental performance
WWPA Member companies are leaders in addressing the
environmental challenges facing the U.S. forest products industry.
Approximately 90 percent of the lumber produced in the Western Woods
region comes from Oregon, Washington, California, Idaho and Montana,
where state Forest Practices Acts and Best Management Practices
are the toughest forest practice laws in place in the U.S.
To foster the sustainability of all Western timberlands
in perpetuity, where timber for products is but one of the many
values assigned to and respected in these working forests, the following
and more are fully regulated:
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protection for threatened and endangered species;
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wildlife habitat and stream protection;
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watershed, wetlands and riparian areas protection;
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soil conservation and site productivity;
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logging practices, with a State Forester overseeing
every logging operation on both private and publicly-owned timberlands;
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time-specified, site-specific, multi-species reforestation;
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limitations on the application of fertilizer and
herbicides; and
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scenic corridors protection (in Oregon).
Quality control
The WWPA grademark identifies
Western lumber products backed with assurances for quality, performance
and technical support. WWPA maintains a team of lumber inspectors
throughout the Western region to monitor the grading and quality
control of Western lumber products from WWPA Member mills, ensuring
products consistently meet grade specifications. Additionally, WWPA
has technical experts on staff with training and work experience
in design, engineering, lumber specifications, code conformance,
construction, manufacturing, wood technology and forestry. From
the Association's headquarters, these experts offer technical assistance
in all aspects of Western lumber end use for WWPA Member company
products.
To order a full-color version of this publication,
complete with photos and examples of grades, or any other WWPA title
referred in this text, go to the WWPA Online
Publications Store.
For a list of WWPA Member mills that produce Hem-Fir lumber products,
go to the WWPA Online Buyers' Guide section.
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