Glossary

Lumber Terminology

A reference guide to the terms and language used in the reclaimed lumber industry.

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This glossary covers 83 terms commonly encountered when buying, selling, specifying, and working with reclaimed lumber. Definitions are written with both professionals and first-time buyers in mind, with cross-references to related terms where helpful. If you encounter a term not listed here, contact our team — we are happy to explain.

Use the letter navigation below to jump directly to a section, or scroll through the full glossary. Terms marked with “See also” link to related definitions elsewhere in this glossary.

A B C D E F G H I J K L M N O P Q R S T V W Z

A4 terms

Acclimation: The process of allowing wood to adjust to the temperature and humidity of its installation environment before being installed. Typically 48 to 72 hours for flooring and paneling. Essential for preventing post-installation movement, gapping, or cupping. See also: Equilibrium Moisture Content.
Air-Dried: Lumber dried naturally by exposure to air rather than in a kiln. Air-dried wood typically retains 12 to 19 percent moisture content, making it suitable for many exterior applications but generally too wet for interior flooring or furniture without further drying. Air drying can take months to years depending on species, thickness, and climate. See also: Kiln-Dried.
American Chestnut: A once-dominant hardwood species in eastern North America, virtually eliminated by chestnut blight in the early 20th century. Reclaimed American chestnut — sourced from pre-1920s structures — is extremely rare and highly valued for its warm brown color, straight grain, natural rot resistance, and historical significance. One of the most sought-after reclaimed species.
Antique Heart Pine: Pine lumber recovered from structures built before 1900, prized for its tight grain and rich amber-to-red color. The heartwood was naturally more resinous and rot-resistant than modern pine. Sourced from old-growth longleaf yellow pine trees that grew for 200 to 500 years. See also: Heart Pine, Old-Growth.

B5 terms

Barn Wood: Reclaimed lumber sourced from agricultural structures, typically barns, stables, and outbuildings. Barn wood is valued for its weathered appearance, silver-gray patina, and rustic character. Common species include oak, chestnut, hemlock, and pine. Quality varies widely depending on the source structure's age, species, and exposure conditions.
Board Foot: A unit of lumber measurement equal to 1 inch thick by 12 inches wide by 12 inches long (144 cubic inches). The standard unit for pricing lumber in North America. To calculate board feet: (thickness in inches times width in inches times length in feet) divided by 12. See also: Linear Foot.
Bow: A lengthwise curvature across the face of a board, typically caused by uneven drying or internal stress in the wood. Mild bow can often be corrected through re-milling or by restraining the wood during installation. Severe bow may render the piece unsuitable for some applications.
Boxed Heart: The pith (center) of the tree is enclosed within the piece of lumber. Common in timbers and large-dimension stock. Can lead to checking as the wood dries because the pith area has different shrinkage characteristics than surrounding wood. See also: Pith, Check.
Bead Board: A paneling profile characterized by a rounded bead detail milled into the face of each board, creating a distinctive lined pattern when installed. Commonly used for wainscoting, ceiling panels, and porch ceilings. Available as a custom milling profile for reclaimed wood.

C10 terms

Carbon Sequestration: The process by which trees absorb CO₂ from the atmosphere and store it as carbon in their wood fibers. Wood continues to store this carbon for the life of the material. When reclaimed wood is reused rather than landfilled, the stored carbon remains sequestered — making material reuse a form of climate action. See also: Lifecycle Analysis.
Chain of Custody: The documented trail that tracks wood from its source through each step of processing to the end user. In the reclaimed lumber industry, chain of custody includes the source building, salvage date, processing records, and final delivery. New York Lumber provides chain-of-custody documentation with every order via our material passport system.
Character Grade: A grading classification that evaluates the aesthetic qualities of reclaimed wood — patina, color variation, nail holes, saw marks, checking, and other features that add visual interest and tell the wood's story. Character grade is one half of New York Lumber's dual grading system. See also: Structural Grade.
Check: A crack or split along the grain that appears as wood dries, caused by differential shrinkage between the outer and inner layers. Surface checks are cosmetic and common in reclaimed timber; through-checks (extending through the full thickness) may affect structural integrity. In character-graded material, checks are often considered a desirable feature.
Clear: Lumber free of knots, splits, and other defects. Clear-grade reclaimed wood commands premium prices due to its rarity and versatility. FAS (First and Seconds) is the equivalent clear grade in the NHLA hardwood grading system. See also: FAS.
Crook: A lengthwise curvature along the edge of a board (as opposed to bow, which is along the face). Often caused by reaction wood or asymmetric internal stress. May be correctable by ripping the board to a narrower width.
Cross-Grain: Wood grain that deviates from the longitudinal axis of the piece. Can reduce strength significantly and make the wood difficult to plane and sand without tear-out. Cross-grained lumber is typically downgraded for structural applications.
Cup: A curvature across the width of a board, causing the edges to rise above the center (or vice versa). Often correctable with re-milling by planing the concave face flat. Common in flat-sawn boards that have dried unevenly. See also: Flat-Sawn.
Custom Milling: The process of machining reclaimed lumber to specific dimensions, profiles, or surface finishes per customer specifications. Includes planing, re-sawing, profiling (tongue-and-groove, shiplap, etc.), jointing, ripping, and sanding. New York Lumber offers full custom milling services with a 100 board foot minimum.
Cypress: A durable softwood species native to the southeastern United States, valued for its exceptional natural rot resistance and distinctive grain. Reclaimed cypress is sourced from water towers, docks, boats, and Gulf Coast structures. Increasingly rare and correspondingly valued in reclaimed form.

D5 terms

Deconstruction: The systematic dismantling of a building or structure to maximize the recovery of reusable materials, as opposed to demolition which destroys materials in the process. Deconstruction typically recovers 70 to 85 percent of available lumber in reusable condition, compared to 15 to 25 percent from post-demolition sorting. New York Lumber operates a dedicated deconstruction division.
De-nail: The process of removing all nails, screws, staples, and embedded metal from reclaimed lumber before resurfacing or resale. A critical step that requires metal detection equipment and careful hand work to avoid damaging the surrounding wood. See also: Metal Detection.
Dimensional Lumber: Lumber cut to standard widths and thicknesses (e.g., 2x4, 2x6, 2x8). Note that nominal sizes differ from actual dimensions — a nominal 2x4 actually measures 1.5 by 3.5 inches. Reclaimed dimensional lumber may be closer to full nominal dimensions because older sawing practices used different standards.
Douglas Fir: A strong, versatile softwood species common in reclaimed lumber from both West Coast and East Coast structures. Recognized by its orange-red heartwood, prominent grain pattern, and excellent strength-to-weight ratio. One of the most common species in reclaimed beams and structural timbers. Widely used for exposed beams, flooring, and paneling.
Dry Rot: Fungal decay that occurs in wood exposed to persistent moisture, despite the misleading name. Dry rot breaks down wood fiber, making it soft, crumbly, and structurally unsound. All incoming reclaimed material at New York Lumber is inspected for rot, and affected areas are rejected or cut away.

E2 terms

Equilibrium Moisture Content (EMC): The moisture content at which wood is neither gaining nor losing moisture relative to its surrounding environment. Interior spaces in the Northeast typically have an EMC of 6 to 9 percent; exterior conditions range from 12 to 19 percent depending on season. Lumber should be installed at or near the EMC of its intended environment. See also: Acclimation.
End Grain: The cross-section of a board showing the cut ends of wood fibers. End grain absorbs and releases moisture much faster than face or edge grain, making it important to seal end grain in exterior applications. In flooring, end-grain blocks are sometimes used as a distinctive surface material.

F5 terms

FAS (First and Seconds): The highest grade in the NHLA hardwood grading system. Boards must yield at least 83.3 percent clear cuttings from one face. FAS is the benchmark for premium-quality hardwood. In reclaimed lumber, FAS-equivalent grades are uncommon and command significant premiums.
Flat-Sawn: Lumber cut tangent to the growth rings, producing a cathedral-like grain pattern on the face. Also called plain-sawn. The most common and economical sawing method. Flat-sawn boards are more prone to cupping than quarter-sawn boards. See also: Quarter-Sawn, Rift-Sawn.
Flitch: A thick slab of wood sawn from a log, sometimes with bark edges (wane) remaining. Used in custom milling to produce bookmatched panels, wide planks, or live-edge slabs. Reclaimed flitches are occasionally recovered from timber-frame structures or large-dimension beams.
Flooring Grade: A grade classification specific to wood flooring products, evaluating flatness, dimensional consistency, tongue-and-groove fit, and surface quality. New York Lumber's flooring-grade standard requires moisture content of 6 to 8 percent, dimensional tolerance of plus or minus 1/32 inch, and profile fit verified by test assembly.
FSC (Forest Stewardship Council): An international organization that certifies responsible forestry practices and provides a chain-of-custody certification for wood products. While FSC certification applies primarily to new timber, New York Lumber documents reclaimed material provenance at an equivalent level of transparency.

G4 terms

Grade: A classification of lumber quality based on the number, size, and type of defects present. Different grading systems exist for hardwoods (NHLA), softwoods (ALSC), and structural timber (engineering grades). New York Lumber uses a proprietary dual grading system that evaluates both structural integrity and aesthetic character. See also: Character Grade, Structural Grade.
Grain: The arrangement and direction of wood fibers. Describes both the visual appearance (grain pattern) and the structural characteristics (grain direction) of a piece of wood. Straight grain is strongest; cross-grain, spiral grain, and interlocked grain present varying challenges for machining and structural performance.
Green Lumber: Freshly sawn lumber that has not been dried. Moisture content can be 30 percent or higher. Green lumber is heavier, more prone to movement, and susceptible to mold and staining. All reclaimed wood processed by New York Lumber is kiln-dried before sale.
Growth Rings: The concentric rings visible in a cross-section of wood, each representing one year of growth. Old-growth timber typically shows 20 to 30 or more rings per inch, indicating slow, dense growth. Modern plantation wood typically shows 4 to 8 rings per inch. Ring density is a key indicator of wood quality and strength.

H5 terms

Hardwood: Wood from broadleaf (deciduous) trees such as oak, maple, cherry, walnut, and ash. The term refers to the botanical classification (angiosperms), not actual hardness — some hardwoods (like basswood and poplar) are softer than some softwoods (like Southern yellow pine). Common reclaimed hardwoods include white oak, red oak, maple, chestnut, elm, and ash.
Heart Pine: The dense, resinous heartwood of longleaf yellow pine (Pinus palustris). Old-growth heart pine was one of the most important structural and flooring woods in American construction from the 1700s through the early 1900s. The species was massively over-harvested, making reclaimed heart pine the only practical source for this exceptional material. See also: Antique Heart Pine.
Heartwood: The dense, innermost wood of a tree, typically darker in color than the surrounding sapwood. Heartwood is formed as the tree's living cells die and become impregnated with extractives — natural chemicals that provide color, rot resistance, and durability. Old-growth timber has a much higher heartwood-to-sapwood ratio (80 to 95 percent) than modern plantation wood (30 to 50 percent).
Heat Treatment: Heating lumber to 160 degrees Fahrenheit or higher core temperature for a minimum of 30 minutes to eliminate insects, larvae, and eggs. Required by ISPM-15 international standards. New York Lumber heat-treats all reclaimed wood as part of our kiln drying process — we never use chemical pest treatments.
Hemlock: A softwood species common in reclaimed lumber from Northeast structures. Eastern hemlock is lighter in color and less dense than Douglas fir, with a subtle, even grain. Often used for framing, barn construction, and industrial buildings. Reclaimed hemlock is popular for rustic paneling and barn-style interiors.

I1 term

ISPM-15: International Standards for Phytosanitary Measures No. 15 — the global standard governing the treatment of wood materials to prevent the international spread of pests. Requires heat treatment to 56 degrees Celsius (133 degrees Fahrenheit) core temperature for 30 minutes. New York Lumber exceeds this standard by treating to 71 degrees Celsius (160 degrees Fahrenheit).

J2 terms

Janka Hardness: A standardized measure of wood hardness determined by the force required to embed a 0.444-inch steel ball halfway into the wood surface. Measured in pounds-force (lbf). For reference: white oak measures 1,360 lbf, heart pine 1,225 lbf, Douglas fir 660 lbf. Useful for comparing species suitability for flooring and high-wear applications.
Jointing: The process of machining a straight, true edge on a board using a jointer. Essential preparation for edge-gluing boards into wider panels and for ensuring tight, gap-free joints in flooring and paneling installations. All New York Lumber milling services include jointing as standard.

K2 terms

Kiln-Dried: Lumber dried in a controlled oven (kiln) to reduce moisture content to target levels — typically 6 to 8 percent for interior use and 12 to 15 percent for exterior use. Kiln drying stabilizes the wood, reduces future movement, eliminates pests, and prepares the material for machining and finishing. All New York Lumber reclaimed wood is kiln-dried. See also: Air-Dried, Moisture Content.
Knot: A cross-section of a branch embedded in lumber. Knots can be tight (firmly attached to surrounding wood) or loose (may fall out or already have separated). In structural grading, knots reduce the rated strength of a piece. In character grading, knots add visual interest and are often considered a desirable feature of reclaimed wood.

L4 terms

LEED: Leadership in Energy and Environmental Design — a green building certification system developed by the U.S. Green Building Council. Using reclaimed materials can earn credits under multiple LEED categories, most directly MR Credit: Building Product Disclosure and Optimization — Sourcing of Raw Materials. New York Lumber provides complete LEED documentation with every order upon request.
Lifecycle Analysis (LCA): A comprehensive assessment of the environmental impacts of a product across its entire life — from raw material extraction through processing, use, and end-of-life disposal. Lifecycle analysis shows that reclaimed lumber produces approximately 84 percent fewer CO₂ emissions than equivalent new lumber when accounting for production, transport, and end-of-life factors.
Linear Foot: A measurement of length only (one foot), regardless of width or thickness. Used for pricing molding, trim, baseboard, crown, and some flooring and paneling products where width and thickness are standardized. See also: Board Foot.
Live Edge: A woodworking style that preserves the natural edge of the tree — including bark, cambium layer, and the organic contour of the trunk — rather than cutting it to a straight line. Popular for tables, shelving, mantels, and decorative elements. Reclaimed live-edge slabs carry unique character from their original structural context. See also: Wane.

M5 terms

Material Passport: A document that accompanies every New York Lumber order, tracing the wood from its source through each processing step. Includes species identification, source information, salvage date, processing details, kiln-drying records, moisture content readings, grade assignments, and quality control sign-off. Supports LEED documentation and provides a permanent record of the material's provenance.
Metal Detection: The use of electromagnetic sensors to locate nails, screws, staples, and other metal objects embedded in reclaimed wood. A critical safety and quality step — hidden metal can damage milling equipment and poses hazards during installation. New York Lumber uses industrial-grade detectors and scans every piece twice (before and after de-nailing). See also: De-nail.
Moisture Content (MC): The percentage of water weight in wood relative to the oven-dry weight of the wood. Calculated as: (wet weight minus oven-dry weight) divided by oven-dry weight, times 100. Critical for determining suitability for different applications. Interior wood should be 6 to 8 percent MC; exterior wood 12 to 15 percent. Measured with pin-type and pinless moisture meters.
Mortise and Tenon: A traditional wood joint where a projecting tenon (tongue) on one piece fits into a corresponding mortise (slot) in another. One of the oldest and strongest joinery methods. Common in reclaimed timber-frame structures, where mortise-and-tenon joints were used to connect beams, posts, and rafters without metal fasteners.
Moulding: Shaped wood profiles used for trim, baseboard, crown, casing, and decorative applications. New York Lumber can produce custom moulding profiles in reclaimed wood, including reproduction of historic profiles for restoration projects. Our moulder can match profiles from customer samples.

N2 terms

NHLA (National Hardwood Lumber Association): The authoritative organization establishing grading rules for hardwood lumber in North America. NHLA grades — FAS, Select, No. 1 Common, No. 2 Common, etc. — are based on the percentage of clear cuttings a board will yield. While designed for new lumber, NHLA grades serve as a reference point for evaluating reclaimed hardwood quality.
Nominal Dimension: The named size of a piece of lumber, which differs from its actual (dressed) dimension. A nominal 2x4 actually measures 1.5 by 3.5 inches after drying and planing. Reclaimed lumber from older structures may be closer to full nominal dimensions because historical sawing and dressing standards differed from modern ones — a reclaimed 2x4 might actually measure 1.75 by 3.75 inches.

O2 terms

Old-Growth: Timber from trees that grew in virgin, unmanaged forests — typically 150 to 500 or more years old. Characterized by extremely tight growth rings (20 to 30 or more per inch), high density, large heartwood-to-sapwood ratio, and superior strength and rot resistance. Old-growth forests have been almost entirely harvested in North America; reclaimed lumber is the only practical source for old-growth wood today. See also: Growth Rings, Heart Pine.
Offcut: A piece of wood remaining after cutting a board to a specified dimension. Offcuts are a natural byproduct of milling. At New York Lumber, usable offcuts are sold as craft or project wood, small offcuts become kindling for local restaurants, and sawdust goes to farms for animal bedding. Zero offcut material goes to landfill.

P4 terms

Patina: The natural surface color and texture that develops on wood over decades of aging and exposure. Patina can include silvery-gray weathering, darkened color from oxidation, smooth wear from foot traffic, and other marks of time. A valued aesthetic characteristic of reclaimed lumber that is impossible to replicate artificially with the same depth and authenticity.
Pith: The very center of a tree trunk, typically soft and spongy. Pith is structurally weak and prone to checking. In lumber, the presence of pith (boxed heart) is generally considered a defect for structural applications but may be acceptable or even desirable in character-graded material. See also: Boxed Heart.
Planing: The process of smoothing lumber surfaces with rotating blades to a specified thickness. In reclaimed wood, planing can reveal hidden colors and grain beneath the weathered surface — a transformation that often surprises first-time buyers. See also: S4S, Skip-Plane.
Provenance: The documented history of a piece of reclaimed wood — where it came from, what structure it served, how old it is, and what species it is. Provenance adds value to reclaimed lumber by connecting the material to its history and by supporting sustainability documentation for green building projects. Every New York Lumber order includes full provenance in the material passport.

Q1 term

Quarter-Sawn: Lumber cut so that growth rings intersect the face at 60 to 90 degrees, producing a straight grain pattern with distinctive ray flecks (most visible in white oak). Quarter-sawn lumber is more dimensionally stable than flat-sawn — it shrinks and swells less across its width — making it preferred for flooring, furniture, and applications where seasonal wood movement must be minimized. See also: Flat-Sawn, Rift-Sawn.

R5 terms

Reaction Wood: Wood formed in response to the tree growing at an angle (due to wind, slope, or leaning). In softwoods, reaction wood (compression wood) is denser and harder on the compressed side. In hardwoods, reaction wood (tension wood) is denser on the stretched side. Reaction wood can cause unpredictable warping and movement during drying and machining.
Reclaimed Lumber: Wood salvaged from existing structures, industrial sites, or other sources and repurposed for new construction or woodworking projects. Distinct from recycled wood (which is ground up and reformed into composite products), reclaimed lumber retains its solid form and is reprocessed through de-nailing, inspection, kiln drying, and milling. The core material of New York Lumber's business.
Re-Saw: The process of cutting a thick piece of lumber into thinner pieces using a bandsaw. Re-sawing is used to produce thinner stock from thick reclaimed timbers, to create bookmatched panels, and to maximize the yield from rare or valuable species. New York Lumber's re-saw has a 24-inch capacity.
Rift-Sawn: Lumber cut so growth rings intersect the face at 30 to 60 degrees. Produces a straight, consistent grain pattern without the ray flecks visible in quarter-sawn oak. More stable than flat-sawn but less so than quarter-sawn. Relatively uncommon because it produces more waste in the sawing process.
Rough-Sawn: Lumber that has been sawn to approximate size but not planed smooth. Retains saw marks on all surfaces. Many reclaimed wood buyers prefer rough-sawn material for its raw, authentic appearance. Rough-sawn stock is also the starting point for custom milling to specific dimensions and profiles.

S7 terms

S4S: Surfaced Four Sides — lumber that has been planed smooth on all four faces (both flat faces and both edges), ready for use. S4S is the most common processing level for finished applications like flooring, paneling, and furniture. See also: S1S, S2S, Planing.
Sapwood: The lighter-colored outer wood of a tree, between the bark and heartwood. Sapwood is the actively growing part of the tree; it is softer, less durable, and more susceptible to rot and insect damage than heartwood. In reclaimed lumber, sapwood is generally considered less desirable for structural and exterior applications but can add visual contrast in interior applications.
Shiplap: A milling profile in which the edges of each board are rabbeted (notched) so that they overlap when installed, creating a distinctive shadow line between boards. Popular for wall cladding, ceiling paneling, and exterior siding. Available as a custom milling profile for reclaimed wood at New York Lumber.
Skip-Plane: A light planing pass that cleans the surface of reclaimed wood while preserving much of the original patina, character marks, and texture. Skip-planing removes loose material, dirt, and surface irregularities without creating a fully smooth, uniform surface. Popular for applications where an aged, authentic appearance is desired but a rough-sawn finish is too unrefined.
Softwood: Wood from coniferous (needle-bearing) trees such as pine, fir, spruce, and hemlock. The term refers to botanical classification (gymnosperms) — some softwoods, like longleaf pine and Douglas fir, are actually quite hard. Common reclaimed softwoods include heart pine, Douglas fir, eastern white pine, hemlock, and spruce.
Structural Grade: A grading classification that evaluates a piece of reclaimed wood's load-bearing capacity, dimensional stability, and defect impact. Structural grade is one half of New York Lumber's dual grading system. Structural-grade material is suitable for use in beams, posts, joists, and other load-bearing applications when approved by a structural engineer. See also: Character Grade.
Sustainability Certificate: A document issued by New York Lumber that quantifies the environmental benefits of a customer's reclaimed wood purchase. Includes estimated CO₂ savings, tree equivalents preserved, water conserved, energy saved, and landfill diversion weight. Suitable for inclusion in LEED documentation, project sustainability reports, and client presentations.

T3 terms

Timber: Large-dimension structural wood, typically 5 inches or greater in the smallest dimension. Common in post-and-beam and heavy timber construction. Reclaimed timbers are among our most dramatic and sought-after products — hand-hewn beams, massive Douglas fir posts, and century-old oak girders with centuries of structural service behind them.
Tongue-and-Groove (T&G): A milling profile where one edge has a protruding tongue and the other a matching groove. When installed, the tongue of one board fits into the groove of the next, creating a tight, interlocking surface. Used for flooring, paneling, ceiling boards, and siding. One of the most commonly requested milling profiles for reclaimed wood.
Twist: A distortion in which the four corners of a board do not lie in the same plane. Effectively a combination of bow and crook occurring simultaneously. Twist is generally more difficult to correct than simple bow or cup and may require re-sawing or ripping the piece to smaller dimensions.

V1 term

Virgin Timber: Wood harvested from forests that have never been commercially logged — original, old-growth forests. Virtually no virgin timber remains available for commercial harvest in the continental United States. Reclaimed lumber from pre-1900 structures is often the product of virgin timber harvests, making it an irreplaceable resource.

W3 terms

Wane: Bark or missing wood along the edge or corner of a piece of lumber. In conventional grading, wane is a defect. In reclaimed and character-graded wood, wane edges (also called live edges or natural edges) are often desired for their organic appearance and are featured in tables, shelving, mantels, and accent pieces. See also: Live Edge.
Warp: Any deviation from a flat, true surface in lumber. The four types of warp are bow (lengthwise face curvature), cup (widthwise curvature), crook (lengthwise edge curvature), and twist (corners not coplanar). Warp results from uneven drying, internal stress, or reaction wood. Proper kiln drying and storage minimize warp in reclaimed lumber.
Weathering: The natural degradation and color change of wood surfaces exposed to sunlight, rain, wind, and temperature cycles. Weathered wood develops a distinctive silver-gray patina caused by UV degradation of lignin. In reclaimed lumber, weathered surfaces are often preserved for their aesthetic character in rustic and industrial-style applications.

Z1 term

Zero-Waste: An operational philosophy and practice in which no material is sent to a landfill. New York Lumber operates on a strict zero-waste-to-landfill policy: all byproducts of our processing — sawdust, offcuts, bark, metal fasteners — are diverted to productive secondary uses including animal bedding, kindling, composting, and metal recycling. In 2024, our facility sent zero pounds of material to landfills.