Post on 19-Dec-2015
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Dr. David BriggsProfessor, Forest products & Operations Research
Director, Stand Management & Precision Forestry CooperativesCollege of Forest Resources, University of Washington, Seattle, WA
Forest Products
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Outline
I. Resource Background
II. Context for Wood Product Discussion
III. Structural Lumber Products
IV. Structural Panel Products
V. Wood-Nonwood Composites
File: ESRM 101/ESRM_101_Forest_Products
Last update: February 13, 2006
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I. Resource Background
A. Global Consumption of Wood & Other Materials
B. Forest Resources in the US and WA
C. Harvest & Harvest Use in the US & WA
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Softwood (Conifer)
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Hardwood
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A. Material Consumption (2005)
•Wood is the dominant material used by man
•Industrial Roundwood = wood for fuel (cooking, heating, etc) + industrial roundwood
•Industrial roundwood = wood (logs) for lumber, veneer, pulp, etc.
World Material Consumption, 2005
0
0.5
1
1.5
2
2.5
3
3.5
4 Billion Metric Tons Billion Cubic Meters
US Material Consumption, 2005
0
0.1
0.2
0.3
0.4
0.5
0.6 Billion Metric Tons Billion Cubic Meters
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Global Wood Harvest & Use3.425 billion m3 (~ 2.1 billion tons)
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
4000000
oo
o c
ub
ic m
eter
s
World
US
World
51% fuelwood (cooking & heating)
•49% industrial roundwood (logs)
(7%) utility poles, pilings, posts, log homes, etc
(26%) sawlogs & veneer logs
•lumber, veneer (plywood, etc.)
•chips sold to industries below
(10%) pulp & paper
•thinnings, tops & low quality logs from trees harvested for other products
•does not include chips from other wood industries or recycled fiber
(5%) OSB, MDF, hardboard, etc.
•US
•16% fuelwood
•84% industrial roundwood
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B. Forest Resources in the US & WAUS Forest Land (747 million acres)
67%
7%
26%
Timberland Reserved Other
US Land (2,263 million acres)
33%
67%
Forest Land Other land
Washington Land (42.6 million acres)
51%49%
Forest Land Other land
Washington Forest Land (21.9 million acres)
80%
16%
4%
Timberland Reserved Other
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B. Ownership of Forest Land
US Total Washington US Total WashingtonAcres, million 747 22 503 14Public 42% 55% 29% 49%Private 58% 45% 71% 51%
100% 100% 100% 100%PublicFederal
USFS 46% 67% 66% 71%BLM 15% 0% 4% 0%Other 16% 20% 5% 2%
State 19% 24% 20% 24%County, City 4% 3% 5% 3%
100% 114% 100% 100%PrivateForest Industry 16% 44% 19% 46%Non-industrial 84% 56% 81% 54%
100% 100% 100% 100%
Forest Land TimberlandForestland - reserved - low productivitySupports ≥ 10% tree cover
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Public Land Ownership in WA
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Ownership of Timber Volume: WA
47%
16%
19%
18%
USFS Other Public Industry NIPF
Ownership of Timber Volume: US
45%
11%
14%
30%
USFS Other Public Industry NIPF
Ownership of Timber Volume
• Volume is on Timberland
• Much of the volume on USFS and Other Public land is currently unavailable
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Volume by DBH Class: OR & WA
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
6 8 10 12 14 16 18 20 21-28.9 >29
mil
lio
n c
ub
ic f
eet
1953 1963 1977 1987 1997
•Ave dbh harvested in 1976 = 27.5 inches•Most mills cannot process large diameter trees
•Ave dbh harvested in 1997 = 16.1 inches•Median log diameter = 11.4 inches
• Most of large diameter timber is on public land
and is unavailable
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Removals in US: 16,021 million cubic feet
63%
37%
Softwoods Hardwoods
• Washington
– Supplies 5.4% of US total
– 7.9% of softwood
– 1.1% of hardwood
Removals in WA: 865 million cubic feet
92%
8%
Softwoods Hardwoods
B. Harvest Removals
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Sources of logs in WA by landowner type
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
Lo
g v
olu
me
(M
bf,
Sc
rib
ne
r)
19681970
19721974
19761978
19801982
19841986
19881990
19921994
19961998
20002002
Calendar year ending December
National Forest Other public Forest industry own supply Other private
Ownership source of logs consumed by Washington sawmills,1968 to 2002
Source: WA State Mill Surveys (various) increasingdecreasing decreasing decreasing
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Utilization of RemovalsUse of Hardwood Removals: US
31%
2%
34%
4%
28%
0%
1%
Saw logs Veneer logs Pulpwood Composite products
Fuelwood Posts, poles, and pilings Miscellaneous products
Use of Softwood Removals: US
52%
11%
28%
1%
5%
2%
1%
Saw logs Veneer logs Pulpwood Composite products
Fuelwood Posts, poles, and pilings Miscellaneous products
Use of Softwood Removals: WA + OR
71%
17%
2%
0%
6%4% 0%
Saw logs Veneer logs Pulpwood Composite products
Fuelwood Posts, poles, and pilings Miscellaneous products
Use of Hardwood Removals: WA + OR
46%
11%3%
0%
40%
0%
0%
Saw logs Veneer logs Pulpwood Composite products
Fuelwood Posts, poles, and pilings Miscellaneous products
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What size? What properties?
II. Context for WOOD PRODUCTS
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joists
wall framing
Long, “deep” pieces
“Quality” driven by strength & stiffness (design values) straightness (dimensional stability)
beams
1. Construction dominates US wood use
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Solid-sawn softwood lumber consumption
Construction (Residential & Non-Res.) – 52% of Consumption
Repair and Remodeling – 30% of Consumption
0
5,000
10,000
15,000
20,000
25,000
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
SW
Lum
ber
Consu
mpti
on (
MM
BF)
Residential Construction
Repair & Remodel
Material Handling
Nonresidential Construction
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2. Tree/log size is getting smallerAverage breast-height diameter of softwood timber harvested on private timberlands in the US
Pacific Northwest coast region and on DNR-managed trust lands in Washington state, 1976 to 2050
0
5
10
15
20
25
30
1970 1980 1990 2000 2010 2020 2030 2040 2050 2060
Calendar year ending December
Mea
n D
BH
(in
ches
)
RPA Base Projection DNR recalculated sustainable harvest (est.)
Source: Haynes, R. (Ed.) 2003. An analysis of the timber situation in the United States: 1952 to 2050. USDA Forest Service, Pacific Northwest Research Station, Portland, Oregon
16 inch ave tree dbh DNR11.4 inch median log diameter in 1998; (Spelter FPL-RP-611, 2003)
12 inch diameter @ top of 5 m butt log 19 ringsAge of tree ~ 30 years
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3. Trees of a given size can be grown in less time
• Juvenile wood:(red + yellow)
– red + yellow (cross-hatched)
– lower specific gravity (density)
– Higher microfibril angle
– Lower stiffness & strength
– More shrinkage
Age = 70Age = 30
Much more product from the fast grown tree
will be from the juvenile wood core
70 years 30 years
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4. Visual grades do not assess wood properties
0
10
20
30
40
50
60
No. 1Peeler
No 2 Peeler No 3 Peeler No 1 Saw Special Mill No 2 Saw No 3 saw No 4 Saw
Percent Distribution of Douglas-fir Log Grades: (WA DNR Sales Cut volume. Dual Scaling Study in 2000)
No correlation between visual log grades and properties of wood inside!
>= 12 inches log diam.<= 2.5 inch knot diam.No rpi limit
Source: _____. 2001. Critique of cross-Border Comparisons Relating to British Columbia in the Department of Commerce’s Preliminary Determination. In the matter of: Countervailing Duty Investigation of Certain Softwood Lumber Products from Canada. Joint Report by H&W Saunders Ltd and Wesley Rickard, Inc. to Province of British Columbia and the BC Lumber Trade Council. Folio # 3.
>= 6 inches log diam.<= 3 inch knot diam.No rpi limit
A diameter sort!Quality is very variable
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5. Engineered wood products (EWP) are replacing traditional products
• More efficient yield from smaller trees• Can combine wood “elements” from different trees to create
products with uniform, targeted properties
• Overcomes limitation of small tree size on product dimensions• Improves straightness and stability
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II. Context for WOOD PRODUCTS
Wood “Elements”
Wood cells (fibers) Chemicals
“Solid” wood Wood fragments
Wood fragments, cont.
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Many EWP’s use lumber & veneer that is stress-rated
for stiffness and/or strength glulam
Glulam, I beam & joist LVL, I-beam & joist
glulam LVL, I-beam & joist
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Stress-rating measures stiffness
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“Stiffness” MOE (modulus of elasticity, “E”)(bending test of lumber is shown, can do round logs also)
Stress at failure, Pmax
P’
D = deflection
max2
1.5P l
MORbd
Stress at proportional limit, P’'
21.5
P lFSPL
bd
Modulus of Elasticity
' 3
3
1
4
P lMOE
D bd
l = span; distance between center line of supports; generally not the length of the piece of lumber
b = breadth; either beam width or thickness depending on placement with respect to loading
d = depth through which load acts; either beam width or thickness depending on placement with respect to loading
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Stress-rating Technology: Lumber & Veneer
Ultrasonic test
Mechanical test
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Stress-rating Technology: Logs and Treesacoustic velocity estimates stiffness
Fibre-gen
ST 300Fibre-gen
HM 200™
TreeSonic
Fakopp
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EWP designers place high & low rated “elements” where needed to achieve a specified product strength/stiffness
Low
High
High
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Other EWP’s combine small elements, resins, plastics, etc. to get homogeneous, stiff, strong composites.
Strand lumber OSB, I-beam & joist
Parallam lumber Wood/plastic
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III. Structural Lumber Products
A. Solid-sawn lumber
B. Engineered composite lumber1. Laminated & Finger-jointed lumber
2. Lumber from veneer
3. Lumber from strands
4. I-beams & joists
C. Competitors: steel, concrete
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A. Solid-sawn softwood lumber
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0
1,000
2,000
3,000
4,000
5,000
Lu
mb
er p
ro
du
cti
on
(M
Mb
f)
0
50
100
150
200
250
19681970
19721974
19761978
19801982
19841986
19881990
19921994
19961998
20002002
Calendar year ending December
Lumber production (LHS)Number of sawmills (RHS)
Comparison of annual lumber production with number of mills forsawmills in Washington, 1968 to 2002
Source: WA State Mill Surveys (various)
WA: 13% of US Softwood Lumber Production
Production increasing but number of mills is decreasing a few large highly efficient ones
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Log Size/Quality & Mill TechnologyAverage breast-height diameter of softwood timber harvested on private timberlands in the US
Pacific Northwest coast region and on DNR-managed trust lands in Washington state, 1976 to 2050
0
5
10
15
20
25
30
1970 1980 1990 2000 2010 2020 2030 2040 2050 2060
Calendar year ending December
Mea
n D
BH
(in
ches
)
RPA Base Projection DNR recalculated sustainable harvest (est.)
Source: Haynes, R. (Ed.) 2003. An analysis of the timber situation in the United States: 1952 to 2050. USDA Forest Service, Pacific Northwest Research Station, Portland, Oregon
11.4 inch median log diameter in 1998 (Spelter FPL-RP-611, 2003)
Difficult to get large lumber dimensions from small trees/logs
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Tree/log size limits ability to get pieces needed for large, open room spans
joists
Wall framing
S4L quality is driven by strength & stiffness design values straigtness
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Quality is highly variable from tree to tree
• Variability due to biology of how trees grow & produce wood
• Leads to non-uniform performance of solid-sawn lumber
Age = 70Age = 30
•red (natural): high average, high variation, low safe design value•Blue, green (engineered) low variation & higher design values
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B. Engineered composite lumber products 1. Glued Laminated Lumber (GLULAM beams)
(APA the Engineered Wood Association)
• Composed of wood laminations, or "lams," bonded together with strong, waterproof adhesives.
• “lams” are typically lumber two inches or less in thickness and can be a variety of species.
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Glulam Applications: Residential (APA the Engineered Wood Association)
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Glulam Applications: Nonresidential (APA the Engineered Wood Association)
Large open areas Curved arches
Bridges
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2. Finger-jointed/Edge Glued Lumber• Composed of small pieces, often salvaged from slabs, edgings, and end
trims from lumber manufacture) bonded together with waterproof adhesives.
• Finger-join end to end, then edge to edge to get wider pieces, then top to bottom to make thicker pieces
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2. Lumber from Veneer• Laminated veneer lumber (LVL), also called structural composite
lumber (SCL) is created by layering dried and graded wood veneers with waterproof adhesive into blocks of material known as billets that are cured in a heated press. The billet is then sawn to various dimensions.
• In LVL, the grain of each layer of veneer runs in the same direction, rather than cross-lamination which is typical of other engineered wood products such as plywood. LVL out-performs conventional lumber when either face- or edge-loaded and is virtually free from warping and splitting
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LVL Applications (APA The Engineered Wood Association)
LVL glued side-by side to make thicker beam
LVL in flanges of I-beams & joists
LVL in standard lumber sizes
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3. Lumber from Strands• Oriented strand lumber (OSL), parallel strand lumber (PSL) and similar
products are manufactured from waterproof heat-cured adhesives and long, rectangularly shaped wood strands that are arranged in parallel to the length of the product.
• Strand products are made as large, continuous mats or billets, that are sawn into various dimensions.
(APA the Engineered Wood Association)
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OSL Applications (APA the Engineered Wood Association)
Headers
Framing
•The lumber analogue to oriented strand board but
• longer strands
•more alignment
•made to mimic lumber sizes & uses
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ParallamLonger strands (from veneer) pressed into a large (20x20) cross-section continuous billet. Sawn off to desired length and ripped to beam and column sizes. Can see this at new CUH building.
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4. Wood I-beams, joists & trusses• I-joists are comprised of top and bottom flanges of various widths united
with webs of various depths. • The flanges resist common bending stresses, and the web provides
outstanding shear resistance• Flanges may be solid-sawn lumber or structural composite lumber (LVL)
for Web may be plywood or oriented strand board (OSB).
(APA the Engineered Wood Association)
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4. Wood I-joists & trusses
LVL or machine stress graded lumber flanges & oriented strand board web
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C. Competitors: Steel, Concrete, etc.
Require much more energy to produce than woodMuch greater demand for fossil fuelsMuch greater carbon emissions
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IV. Structural Panel Products
A. Plywood
B. Oriented Strand Board
C. Structural Insulated Panels
D. Particleboard
E. Fiberboards
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A. Plywood
Veneer manufacture
Sheet
Grain in any sheet is perpendicular to adjacent sheets
• Manufactured from thin sheets of cross-laminated veneer and bonded under heat and pressure with strong adhesives.
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Wall & Roof Sheathing, sub-flooring, siding (APA the Engineered Wood Association)
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Overlaid PlywoodConcrete forms Skid-resistant surfaces
Billboards, highway signs
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B. Oriented Strand Board (OSB)• OSB is manufactured from waterproof heat-cured adhesives and rectangular-
shaped wood strands that are arranged in cross-oriented layers. • Produced in huge, continuous mats, which are sawn to standard panel sizes• OSB is a solid panel product of consistent quality with no laps, gaps or voids • A structural wood panel with many of the strength and performance characteristics
of plywood.
(APA the Engineered Wood Association)
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OSB Surfaces
• OSB rough side up for traction • OSB smooth side
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Wall & Roof Sheathing, sub-flooring, siding (APA the Engineered Wood Association)
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C. Structural Insulated Panels (SIP)
Thick insulating foam between plywood or OSB panels
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D. Particleboard• INPUT: Sawdust, planer shavings, etc., by-products of other wood industries, not
logs• Same process as OSB & LSL but smaller wood elements• Usually 3 layers of particles: those in center are coarser than those on surfaces
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Particleboard Usesmelamine overlay shelving, table tops, etc. flooring or floor underlayment
Veneered for furniture and cabinets
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E. Fiberboard (pulped fibers)
1. Hardboard
2. Insulation board
3. Medium density fiberboard (MDF)
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1. Hardboard
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2. Insulation board• Low density SGg ~ .27-.43
17-25 lb/ft3
• Generally flat sheets• Process
– Similar to wet process hardboard but no hot press is used
– Product thickness is controlled by a simple roller after which the panel is dried
• Uses– Exterior walls of houses
apply panels over the studes and under the siding
– Acoustical ceiling tiles– CELOTEX panels used in
interior wall partitions in buildings; has been largely replaced by gypsum board
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3. Medium Density Fiberboard (MDF)• Medium Density Fiberboard (MDF) is a grainless composite panel
product made from extremely fine wood fibers and manufactured in sheets of various dimensions.
• It is ideally suited for a wide variety of woodworking applications including cabinets, shelving, furniture, store fixtures, moulding and flooring.
Temple-Inland
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MDF, exterior siding and trim
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V. Wood – Non-Wood Composites
A. Wood & Gypsum B. Wood & CementC. Wood & Plastic D. Wood & Fiberglass, Metal, Kevlar, …
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A. Wood/Gypsum Composite: drywall
• Interior wall board – “drywall”,
sheetrock
• Gypsum with paper surface: US
• Gypsum mixed with recycled paper fiber and pressed into a wallboard panel: Europe
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B. Wood/Cement Composites: Siding
Hardi-plank: cement, sand, & wood fiber; simulated wood grain
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Wood/Cement Composites: Roof Tile
• Wood Fiber & cement
• Molded to simulate cedar shake
topbottom
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C. Wood/Plastic Composite: “Lumber”• Recycled plastic shopping
bags & recycled wood fiber from paper
• Molded into lumber shape• Decks, park benches, etc.• Poor chemical bonding• Low strength & stiffness• Degrades
– Ultraviolet– Water gets in to the wood
particles which swell & shrink
– As opens up, wood decay starts
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Combine Wood Flour with Plastics & Extrude
• New Wood Materials Engineering Lab at WSU
• Wood flour, plastic resins, additives– Excellent chemical
bonding– High strength & stiffness
• Extruded into various shapes
• Decks (Ex Trex and others), windows
• Siding & roofing products under development
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D. Wood, Metal, Glass, Vinyl, etc. (Weathervane Windows)
• Modern high efficiency windows– Pre-finished exterior skin;
vinyl or aluminum– High efficiency glass– Solid wood on interior for
natural look– Hollow extruded exterior
frame of wood-plastic composite; negligible shrink & swell
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Questions?