Definition: Lumber or timber is a term used to describe wood, either standing or that has been processed for use — from the time trees are felled, to its end product as a material suitable for industrial use — as structural material for construction or wood pulp for paper production. In the U.K. and Australia, "timber" is a term also used for sawn wood products (that is, boards), whereas generally in the United States and Canada, the product of timber cut into boards is referred to as lumber. In the United States and Canada sawn wood products of five inches (127 millimeters) (nominal size) diameter or greater are sometimes called "timbers".

Wood cut from Victorian Mountain AshLumber is supplied either rough or finished. Rough lumber is the raw material for furniture making and other items requiring additional cutting and shaping. It is available in many species, usually hardwoods. Finished lumber is supplied in standard sizes, mostly for the construction industry, and is primarily one of a few coniferous (needle-bearing) species such as pine, cedar, hemlock, fir or spruce.

 

Engineered lumber
Engineered lumber is lumber created by a manufacturer and designed for a certain structural purpose. The main categories of engineered lumber are:

Laminated Veneer Lumber – Generally called "LVL", they come in 1-3/4″ thicknesses with depths such as 9″, 11-7/8″, 13″, 16″, 18″, 24″, and are typically doubled or tripled up. They function as beams to provide support over large spans such as removed support walls and garage door openings, places where dimensional lumber isn't structurally sound to use, and also in areas where a heavy load is bearing from a floor, wall or roof above on a somewhat short span where dimensional lumber isn't practical. This type of lumber cannot be altered by holes or notches anywhere within the span or at the ends as it compromises the integrity of the beam, but nails can be driven into it wherever necessary to anchor the beam or to add hangers for I-joists or dimensional lumber joists which terminate at an LVL.

Wood I-joists – Sometimes called "TJI" or "Trus Joists", which are both brands of wood I-joists, they are used for floor joists on upper floors and also in 1st floor conventional foundation construction on piers as opposed to slab floor construction. They are engineered for long spans and are doubled up in places where a wall will be placed over them, and sometimes tripled where heavy roof-loaded support walls are placed above them. They consist of a top and bottom chord/flange made from LVL with a webbing in-between made from OSB (oriented strand board). The webbing can be removed up to certain sizes/shapes according to the manufacturers (and engineers) specifications, but for small holes, wood I-joists come with "knockouts", which are perforated, pre-cut areas where holes can be made easily typically without engineering approval. When large holes are needed, they can typically be made in the webbing only (the top & bottom chords cannot be cut) and only in the center third of the span. Sizes & shapes of the hole, and typically the placing of a hole itself, must be approved by an engineer prior to the cutting of the hole and in many areas, a sheet showing the calculations made by the engineer must be provided to the building inspection authorities before the hole will be approved. Some I-joists are made with W-style webbing like a truss to eliminate cutting and allow ductwork to pass through.

Freshly cut logs showing sap running from beneath barkFinger-Jointed Lumber – Solid dimensional lumber lengths typically max out at lengths of 22′ to 24′, but is made longer by the technique of "finger-jointing" lumber by using small solid pieces, usually 18″ to 24″ long, and joining them together using finger-joints and glue to produce lengths that can be up to 36′ long in 2×6 size. Finger-jointing also is predominant in pre-cut wall studs.

Glu-lam Beams – Created by taking 2×4 or 2×6 stock and glueing the faces together to create beams such as 4×12 or 6×16. LVL beams have taken their place in most home construction.

Manufactured Trusses – Trusses are used in home construction as bracing to support the roof rafters in the attic space. It is seen as an easier installation and a better solution for supporting roofs as opposed to the use of dimensional lumber's struts & purlins as bracing. In the southern USA and other parts, stick-framing with dimensional lumber roof support is still predominant. The main drawback of trusses is that less attic space is usable.

Oriented Strand Board – OSB is made by adhering strands of wood in a certain direction and apply glue to make the piece strong for structural purposes. OSB has replaced plywood for use as exterior wall sheathing & roof decking (both in 7/16″ thickness minimum) and in 2nd story flooring in 3/4″ thickness in a tongue-and-groove interlocking pattern, which is nailed and glued to the I-joists. OSB used in wall sheathing & roof decking will swell up if exposed to the elements for even a brief period of time and must be replaced, therefore it is covered by a weatherproof membrane such as felt to protect it, secured with plastic cap nails. House wrapping is used on areas which will be sheathed with vinyl siding. 3/4″ T&G OSB flooring has a coating on it to protect it from the elements for a short period of time until the home is "dried-in" with a roof.

 

 

Softwoods (conifers)
Araucaria
Hoop Pine (Aus.) Araucaria cunninghamii
Parana Pine (Brazil) Araucaria angustifolia
Pehuén or Chile Pine Araucaria araucana
Cedar (Cedrus); also applied to a number of woods from trees in the Cypress family mainly in North America, see Redcedar, Whitecedar and Yellow-Cedar in Softwoods, and to woods from some relatives of the mahogany.
Cypress (Chamaecyparis, Cupressus, Taxodium)
Arizona Cypress (Cupressus arizonica)
Bald Cypress or Southern cypress (Taxodium distichum)
Hinoki Cypress (Chamaecyparis obtusa)
Lawson's Cypress (Chamaecyparis lawsoniana)
Mediterranean Cypress (Cupressus sempervirens)

Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca)
European Yew (Taxus baccata)
Fir (Abies)
Balsam Fir (Abies balsamea)
Silver Fir (Abies alba)
Noble Fir (Abies procera)
Pacific Silver Fir (Abies amabilis)
Hemlock (Tsuga)
Eastern Hemlock (Tsuga canadensis)
Mountain Hemlock (Tsuga mertensiana)
Western Hemlock (Tsuga heterophylla)
Kauri (New Zealand) (Agathis australis)
Kaya (Torreya nucifera)
Larch (Larix)
European Larch (Larix decidua)
Japanese Larch (Larix kaempferi)
Tamarack Larch or Tamarack (Larix laricina)
Western Larch (Larix occidentalis)
Pine (Pinus; Many woods are incorrectly called "Pine". See Araucaria and Douglas-fir above)
Corsican pine (Pinus nigra)
Jack Pine (Pinus banksiana)
Lodgepole Pine (Pinus contorta subsp latifolia)
Monterey Pine (Pinus radiata)
Ponderosa Pine (Pinus ponderosa)
Red Pine (N.Am.) (Pinus resinosa)
Scots Pine, Red pine (UK), Red deal (UK), Redwood (UK, obsolete) (Pinus sylvestris)
White Pine in (N.Am.), Yellow or Weymouth pine (UK, obsolete)
Eastern White Pine (Pinus strobus)
Western White Pine (Pinus monticola)
Sugar Pine (Pinus lambertiana)
Southern Yellow pine (US)
Loblolly Pine (Pinus taeda)
Longleaf Pine (Pinus palustris)
Pitch Pine (Pinus rigida)
Shortleaf Pine (Pinus echinata)
"Redcedar"
Eastern Redcedar, (Juniperus virginiana)
Western redcedar (Thuja plicata)
Redwood (Sequoia sempervirens)
Rimu (New Zealand) (Dacrydium cupressinum)
Spruce (Picea)
Norway Spruce (Picea abies)
Black Spruce (Picea mariana)
Red Spruce (Picea rubens)
Sitka Spruce (Picea sitchensis)
White Spruce (Picea glauca)
Sugi (Cryptomeria japonica)
"Whitecedar"
Northern Whitecedar (Thuja occidentalis)
Southern Whitecedar (Chamaecyparis thyoides)
"Yellow-cedar" (Nootka Cypress Callitropsis nootkatensis, formerly Chamaecyparis nootkatensis)

Hardwoods (angiosperms)
Wooble China Maple Tree
Afzelia (Afzelia)
Agba yun (Synsepalum duloificum)
Albizia (Albizia)
Alder (Alnus)
Black alder (Alnus glutinosa)
Red alder (Alnus rubra)
Applewood or wild apple (Malus)
Ash (Fraxinus)
Black ash (Fraxinus nigra)
Blue ash (Fraxinus quadrangulata)
Common ash (Fraxinus excelsior)
Green ash (Fraxinus pennsylvanica lanceolata)
White ash (Fraxinus americana)
Aspen (Populus)
American aspen (Populus tremuloides)
Bigtooth aspen (Populus grandidentata)
European aspen (Populus tremula)
Ayan (Distemonanthus benthamianus)
Balsa (Ochroma pyramidale)
Basswood (Tilia americana)
Beech (Fagus)
European Beech (Fagus sylvatica)
American Beech (Fagus grandifolia)
Birch (Betula)
American birches
Gray birch (Betula populifolia)
Paper birch (Betula papyrifera)
Sweet birch (Betula lenta)
Yellow birch (B. alleghaniensis syn Betula lutea) - most common birch wood sold in N.Am.
European birches, also Baltic birch (N.Am.)
Silver birch (Betula pendula)
White Birch (Betula pubescens)
Blackbean (Castanospermum australe)
Blackwood (Acacia melanoxylon)
Bocote (Cordia alliodora)
Boxwood or Box (Buxus sempervirens)
Brazilwood (Caesalpinia echinata)
Bubinga (Guibourtia)
Buckeye (Aesculus)
Common Horse-chestnut (Aesculus hippocastanum)
Yellow Buckeye (Aesculus flava)
Butternut (Juglans cinerea)
Carapa (or Andiroba, Carap, Crappo, Crabwood and Santa Maria) (Carapa guianensis) .
Catalpa (Catalpa)
Cherry (Prunus)
Black cherry (Prunus serotina)
Red cherry (Prunus pennsylvanica)
Wild cherry (Prunus avium)
"Brazilian Cherry" Not a Cherry See Jatoba below
Chestnut (Castanea dentata)
Coachwood (Ceratopetalum apetalum)
Cocobolo (Dalbergia retusa)
Corkwood (Leitneria floridana)
Cottonwood, eastern (Populus deltoides)
Dogwood (Cornus spp.)
Ebony (Diospyros)
Andaman marble-wood (India) (Diospyros kurzii)
Ebène marbre (Mauritius, E. Africa) (Diospyros melanida)
Elm
American elm (Ulmus americana)
English elm (Ulmus procera)
Rock elm (Ulmus thomasii)
Slippery elm (Ulmus rubra)
Wych elm (Ulmus glabra)
Eucalyptus (Eucalyptus)
Lyptus
Karri (W. Australia) (Eucalyptus diversicolor)
Mahogany eucalyptus, (New South Wales) (Eucalyptus)
Ironbark Eucalyptus sideroxylon
Jarrah or West Australian eucalyptus (Eucalyptus marginata)
Tasmanian oak or Mountain ash, (Eucalyptus regnans Eucalyptus obliqua Eucalyptus delegatensis)
River Red Gum
Blue Gum Eucalyptus saligna
Greenheart (Guyana) (Chlorocardium rodiei)
Grenadilla (Mpingo) (Dalbergia melanoxylon)
Gum
Blackgum (Nyssa sylvatica)
Blue gum (Eucalyptus globulus)
Redgum or Sweetgum (Liquidambar styraciflua)
Tupelo gum (Nyssa aquatica)
Hickory (Carya)
Mockernut hickory (Carya alba)
Pignut hickory (Carya glabra)
Shagbark hickory (Carya ovata)
Shellbark hickory (Carya laciniosa)
Hornbeam (Carpinus species)
Hophornbeam, Eastern (Ostrya virginiana)
Ipe (Tabebuia impetiginosa)
Iroko (Milicia excelsa syn Chlorophora excelsa)
Ironwood refers to the wood of many tree species noted for the hardness of their wood. Trees commonly known as ironwoods include:** Carpinus caroliniana — also known as American hornbeam
Casuarina equisetifolia — Common Ironwood from Australia
Choricarpia subargentea
Copaifera spp.
Eusideroxylon zwageri
Guajacum officinale and Guajacum sanctum — Lignum vitae
Hopea odorata
Krugiodendron ferreum — Black Ironwood
Lyonothamnus lyonii (L. floribundus) — Catalina Ironwood
Mesua ferrea — also known as Rose Chestnut or Ceylon Ironwood, from Thailand, Laos, Vietnam, Cambodia
Olea spp. — various olive trees
Olneya tesota — Desert Ironwood
Ostrya virginiana — Hop hornbeam
Parrotia persica — Persian Ironwood
Tabebuia serratifolia — Ipe
Jacarandá, Brazilian rosewood (Dalbergia nigra)
Jatobá (Hymenaea courbaril)
Lacewood from the Sycamore(N.Am.) or Plane(UK) trees (Platanus species)
Laurel, California (Umbellularia californica)
Limba (Terminalia superba)
Lignum vitae (Guaiacum officinale and Guaiacum sanctum)
Locust
Black locust or Yellow locust (Robinia pseudacacia)
Honey locust (Gleditsia triacanthos)
acuminata)

Mahogany
Mahogany (African) (Khaya spp.)
Mahogany (West Indies or Cuban) (Swietenia mahagoni)
Mahogany (Honduras, Central and South America) (Swietenia macrophylla)
Mahogany (Philippine), Not a mahogany, see Lauan.
Maple (Acer)
Hard Maple (N.Am.)
Sugar maple (Acer saccharum)
Black maple (Acer nigrum)
Soft Maple (N.Am.)
Manitoba maple (Acer negundo)
Red maple (Acer rubrum)
Silver maple (Acer saccharinum)
European Maples
Sycamore maple (Acer pseudoplatanus)
Meranti (Shorea spp.)
Mpingo (Grenadilla) (Dalbergia melanoxylon)
Oak (Quercus)
American White Oak includes wood from any of the following species of trees:
Bur oak (Quercus macrocarpa)
White oak (Quercus alba)
Post oak (Quercus stellata)
Swamp white oak (Quercus bicolor)
Southern live oak (Quercus virginiana)
Swamp chestnut oak (Quercus michauxii)
Chestnut oak (Quercus prinus or Q. montana)
Chinkapin oak (Quercus muhlenbergii)
Canyon live oak (Quercus chrysolepis)
Overcup oak (Quercus lyrata)
English oak, also French and Slovenian oak barrels (Quercus robur and sometimes Quercus petraea)
Red Oak includes wood from any of the following species of trees:
Red oak (Quercus rubra)
Black oak (Quercus velutina)

Laurel oak (Quercus laurifolia))
Southern red oak (Quercus falcata)
Water oak (Quercus nigra)
Willow oak {Quercus phellos)
Nuttall's oak (Quercus texana or Q. nuttallii)
Willow oak (Quercus phellos)
"Tasmanian oak"; Not an oak see Eucalyptus above
Australian "Silky oak"; Not an oak see Silky Oak below
Obeche or Samba, Ayous, Arere, Wana, Abache (West Africa) (Triplochiton scleroxylon)
Okoumé or "Gaboon" (Aucoumea klaineana)
Oregon Myrtle or California Bay Laurel (Umbellularia californica)
Pear (Pyrus communis)
Pernambuco is another name for Brazilwood (Caesalpinia echinata)
Poplar (Populus; in N.Am., wood sold as poplar is usually Yellow-poplar — see below)
Balsam poplar (Populus balsamifera)
Black poplar (Populus nigra)
Hybrid poplar (Populus × canadensis)
Ramin
Redcedar (Toona ciliata)
Rosewood (Dalbergia spp.)
Sal (Shorea robusta)
Sandalwood (Santalum)
Sassafras (Sassafras albidum)
Sassafras (Australia) (Atherosperma moschatum)
Satinwood (Ceylon) (Chloroxylon swietenia)
Silky Oak (Grevillea robusta) - Sold as Lacewood in North America
Silver Wattle Acacia dealbata
Snakewood
Sourwood (Oxydendrum arboreum)
Spanish-cedar (Cedrela odorata)
American sycamore (Platanus occidentalis)
Teak (Tectona grandis)
Walnut (Juglans)
Black Walnut (Juglans nigra)
Persian Walnut (Juglans regia)
Brazilian walnut; Not a walnut see Ipe above.
Willow (Salix)
Black willow (Salix nigra)
Cricket-bat willow (Salix alba 'Coerulea')
White willow (Salix alba)
Yellow-poplar (Liriodendron tulipifera)

Hardwoods (monocotyledons)
Bamboo (a number of species in Tribe: Bambuseae)
Palmwood (Cocos nucifera) is 'new' wood source that is increasingly being used as an ecologically-sound alternative to endangered hardwoods.