D03D Species

D03D - MATERIAL GUIDES - SPECIES

D03D-1 Hardwood
D03D-2 Hardwood cuts
D03D-3 Hardwood appearance
D03D-4 Harwood grain and texture
D03D-5 Hardwood hardness
D03D-6 Hardwood workability
D03D-7 Hardwood species
D03D-8 Domestic (North American) hardwood species
D03D-9 Imported hardwood species
D03D-10 Domestic (North American) softwood species
D03D-11 Imported softwood species
D03D-12 Non-wood species
D03D-13 Relative hardness or Janka table

Preface:
This reference guide is a discussion of hardwood species that are used in hardwood and engineered hardwood strip, plank, and parquet flooring systems.

1 • HARDWOOD

.01 A variety of domestic (North American, i.e., Canada and continental United States) and imported (Central and South America, Europe, Asia, Africa, and Australia) species are available and used in the manufacturing of hardwood flooring. These include both hardwoods and some softwoods.

.02 Each species possesses different characteristics that make it unique. Most of these become evident when the wood is cut. Different cuts will produce wood pieces with different features and qualities.

2 • HARDWOOD CUTS

.01 Hardwood flooring lumber is either plain-sawn, quarter-sawn, or rift-sawn.

.02 Plain-Sawn lumber is obtained by making the first saw cut on a tangent to the circumference of the log and remaining cuts parallel to the first. Since most of the lumber produced by plain sawing is flat-grained, with some vertical-grained wood included, plain-sawn lumber will tend to contain more variation within and among boards than quarter-sawn lumber, in which nearly all of the wood is vertical-grained. Also, since flat-grained wood is less dimensionally stable than vertical-grained, plain-sawn lumber will tend to expand and contract more across the width of the boards than quarter-sawn lumber.

Other physical differences to consider when choosing plain-sawn lumber rather than quarter-sawn:

Figure patterns resulting from the annual rings and some other types of figures are usually brought out more conspicuously by plain sawing.
Shakes and pitch pockets, when present, extend through fewer boards.

.03 Quarter Sawn lumber is produced by first quartering the log and then sawing each "quarter" perpendicular to the growth rings. Quarter sawing produces relatively narrow boards, nearly all vertical-grained, and creates more waste, making quarter-sawn lumber more expensive than plain-sawn. However, much quarter-sawn wood is obtained by culling the vertical-grained wood that naturally results from plain sawing.

For reasons other than cost, most individuals prefer quarter-sawn wood, although some favour the variety in figuring produced in plain sawing.

Other physical factors to keep in mind when choosing quarter-sawn over plain-sawn wood are:

It twists and cups less.
It surface checks and splits less during seasoning and in use.
Raised grain produced by separation in the annual growth rings does not appear as pronounced.
It wears more evenly.
Figuring due to pronounced rays, interlocked, and wavy grain are brought out more conspicuously.
Sapwood appears only at the edges, and is limited to the width of the sapwood in the log.

.04 Rift sawn lumber is similar to quarter sawing, with many of the same advantages and limitations. It accentuates the vertical grain and minimizes the flake effect common in quarter-sawn oak. The angle of the cut is changed slightly so that fewer saw cuts are parallel to the medullary rays, which are responsible for the flake effect. Rift sawing creates more waste than quarter sawing, making it generally more expensive.

3 • HARDWOOD APPEARANCE

1. Heartwood / Sapwood

.01 Heartwood: Heartwood is the older, harder central portion of a tree. It usually contains deposits of various materials that frequently give it a darker colour than sapwood. It is denser, less permeable, and more durable than the surrounding sapwood.

.02 Sapwood: Sapwood is the softer, younger outer portion of a tree that lies between the cambium (formative layer just under the bark) and the heartwood. It is more permeable, less durable, and usually lighter in colour than the heartwood.

.03 The relative amounts of heartwood and sapwood in a flooring batch may affect the way it accepts stain and finish and, therefore, the finished appearance of the floor. In general, quarter-sawn and rift-sawn flooring which contain less sapwood than plain-sawn flooring, and will tend to have a straighter grain and more uniform appearance. Heartwood is also more dimensionally stable than sapwood, so flooring with a high percentage of heartwood will shrink and swell less than flooring that is mostly sapwood.

Example of oak flooring showing both darker heartwood and lighter sap wood characteristics.

2. Wood Discolouration

Causes

Wood changes color through oxidation and/or photochemical exposure, which is a change that cannot be prevented. This is a naturally occurring phenomenon. All woods will change color, but some more drastically than others. This is a natural change, and should be taken into account when selecting flooring from sample boards.
Some woods darken with age. Some examples of species that darken include American Cherry, Brazilian Cherry (Jatoba), Douglas Fir, and Purpleheart. Not all wood flooring pieces will change colour to the same extent.
Some woods lighten with age such as Black Walnut, Oak and Cork. Not all wood flooring pieces will change colour to the same extent.
Areas covered with rugs or furniture and thereby exposed to less direct light, may change colour at a slower rate than those areas exposed to more sunlight. Window coverings or UV protection may aid in slowing the issue over time, but will not eliminate it.
Partially installed floor protection used during the construction process. Wood floors will exhibit colour change in exposed areas as compared to partially protected/ unexposed areas of the floor.
A repaired area, or newer flooring that does not match the existing untouched flooring. (Different species or subspecies used.)
When sanding multi-species wood floors, some species natural colours from wood dust can bleed into adjoining woods, affecting the natural intended colours within the floor.

Cures

Wood colour change is a natural occurrence and is inevitable when wood surfaces are exposed to UV light. All parties should be made aware of this naturally occurring phenomenon during the sales process. Window coverings or UV protection may aid in slowing the issue over time, but it will not eliminate it.
If shadows (colour contrasts) are left in areas of flooring that have been covered by furniture or area rugs, moving the furniture or area rugs around periodically to expose the covered flooring will help to equalize the colour over time.
Customized color matching, sanding, staining, shading, or tinting lighter areas to match is not recommended for factory finished flooring due to the different visual appearance of factory applied finish compared to site applied finishes.

Oak flooring lightens in UV light

4 • HARDWOOD GRAIN AND TEXTURE

.01 Grain and texture are loosely used to describe similar properties of wood.

.02 Grain: is often used in reference to annual growth rings, as in "fine" or "coarse" grain. It is also used to indicate the direction of fibres, as in straight, spiral, and curly grain. The direction of the grain, as well as the amount of figuring in the wood, can affect the way it is sanded and sawed. Grain is also described as being either "open" or "closed", referring to the relative size of the pores, which affects the way a wood accepts stain and finishes.

.1 Tangential Grain:  Usually called flat grain; easily recognized by its parabolic (arched) effect.  Lumber is considered "flat-grained" when the annual growth rings make an angle of less than 45 degrees with the wide surface of the board.

.2   Radial Grain:  Known as vertical or edge grain; generally more dimensionally stable than flat grain - that is, vertical-grain boards are less likely to expand or contract in width with changes in moisture.  Lumber is considered "vertical-grained" when the annual growth rings make an angle of 45 to 90owith the wide surface of the board.

Note:  In hardwoods, plain-sawn lumber generally contains mostly flat-grained wood, while quarter-sawn lumber is nearly all vertical-grained.  In softwood lumber the terms "flat-grained" and "vertical-grained" are used instead of the terms "plain-sawn" and "quarter-sawn", respectively.  Refer to Types of Saw Cuts below.

.3 Interlocked Grain:  Grain in which the fibres may slope in a right-handed direction several years, then in a left-handed direction for several years, back to right-handed, and so on.  A high degree of interlocked grain may make a wood difficult to machine.

.03 Texture: usually refers to the finer structure of the wood, rather than to the annual rings. It is sometimes used to combine the concepts of density and degree of contrast between spring wood and summer wood in the annual growth rings.

.04 Wood Grain Terminology:

.1 Annual / Growth Rings: Most species grown in temperate climates produce visible annual growth rings that show the difference in density and colour between wood formed early and that formed late in the growing season.  The inner part of the growth rings, formed first, is called "spring wood"; the outer part, formed later in the season, is called "summer wood".

.2 Spring wood:  is characterized by cells having relatively large cavities and thin walls.

.3.   Summer wood:  is characterized by cells having smaller cavities and thicker walls, and consequently they are denser than those in spring wood.

The growth rings, when exposed by conventional sawing methods, provide the grain or characteristic pattern of the wood.  The distinguishing features among the various species result in part, then, from differences in growth-ring formation.  And within species, natural variations in growth ensure the unique character and beauty of each piece of wood.

.4 Figure:  The pattern produced in a wood surface by annual growth rings, rays, knots, and deviations from regular grain.
.5 Medullary Rays:  Medullary rays extend radially from the core of the tree toward the bark. They vary in height from a few cells in some species, to four or more inches in the oaks; they're responsible for the flake effect common to the quarter-sawn lumber in certain species.

Medullary Ray in oak flooring

5 • HARDWOOD HARDNESS

.01 One of the more important properties for wood used in flooring applications is its hardness. This is important in determining the ability of a wood species to withstand denting, marring, and wear. It is also a good indicator of how hard a species is to saw / machine and fasten.

.02 Janka Rating: One method of measuring the hardness of wood is based on a variation of the Brinell hardness test known as the Janka test which measures the load required to embed an 11.28 mm (0.444") diameter steel ball to one-half its depth into a selected species of wood. The results are stated in various ways in different countries, which can lead to confusion, especially since the name of the actual units employed is often not attached. In North America, the measurement is in pounds-force. In Sweden it is in kilogram-force (kgf), and in Australia, Janka hardness ratings are either in newtons (N) or kilonewtons (kN). Sometimes the results are treated as units, e.g., "360 janka."

.03 The hardness of wood usually varies with the direction of the grain. If testing is done on the surface of a plank, the test is said to be of "side hardness". End (i.e end of board) testing is also sometimes done. Testing the cut surface of a stump would also be a test of end hardness. The side hardness of teak, for example, is in the range 3730 to 4800 newtons, while the end hardness is in the range 4150 to 4500 newtons. The most common use of Janka hardness ratings is to determine whether a species is suitable for use as flooring.

.04 The side hardness of wood in regard to flooring represents the resistance of the wood to denting, marring, and wear. A Janka rating for a hardwood floor species is based on an average of side hardness test results for both tangential and radial (i.e. plain-sawn and quarter-sawn) samples under wet and dry (12% moisture content) conditions.

.05 A relative hardness rating listing of wood species used in hardwood flooring is attached at the end of this Part of the NFCA Reference Manual. The higher the rating; the harder the wood. It must be noted however that although this is one of the best methods to measure the ability of wood species to withstand indentations, it should be used as a general guide only when comparing various species of wood flooring. The construction and finish used also play an important role in the durability and ease of maintenance of any wood floor.

6 • HARDWOOD WORKABILITY

.01 The workability of a wood species in regard to its use for flooring depends on the cut.

.02 Machining: This depends on several factors, including density, extent of interlocked or variable grain, hard mineral deposits, and tensions in wood that may cause fibrous and fuzzy surfaces. The degree of checking and separation present will also affect machining ease. Interlocked grain is characteristic of many tropical forest species and causes problems in planing quarter-sawn or rift-sawn boards unless sharpness of knives, cutting angles, and feed rates are carefully controlled. Hard deposits in the cells, such as silica and calcium carbonate, may have a pronounced dulling effect on cutting tools. This effect generally increases as wood is dried to normal working requirements.

.03 Fastening: When fastening some of the denser woods using hand or air powered fasteners (nailers) installers may encounter splitting tongues, as well as failure to secure the fastener even after repeated attempts. This can sometimes be corrected by changing the fastener point of entry. On certain exceptionally dense species, pilot holes may have to be drilled to ease nailing or screwing. Blunting the ends of fasteners may also help prevent splitting.

Though dense, heavy woods normally offer higher fastener withdrawal resistance, less dense species allow the use of more and larger diameter fasteners to compensate for their lower holding ability.

.04 Sanding: Some wood species are highly resinous and tend to clog sandpaper. When working with such species, it may be necessary to use a coarser grit of sandpaper than normal, or to change the sandpaper more often than with other species. Also, the wood dust created by sanding some species may cause an allergic reaction in some people. This is more likely to occur with imported species than with domestic. However, even North American oak has been known to cause skin rash or respiratory difficulties in some individuals. Where this may be a problem, long sleeved shirts, dust masks, and eye protection should be used when sanding. When working with any type of wood refer to the flooring manufacturer's material safety data sheets (MSDS) for hazards in regard to wood dust particularly during sanding.

7 • HARDWOOD SPECIES

.01 A variety of domestic (North American) and imported species (from Europe, Asia, Africa, and Australia) of tree wood is available and used in the manufacturing of hardwood flooring in general.

.02 Design authorities must also be aware of the difference between "marketing" names and the actual species name. Some imported hardwoods are marketed as traditional North American species such as oak, maple, and cherry. For example, so-called "Tasmanian oak" is not oak at all but an Australian eucalyptus. "Brazilian Cherry" isn't cherry either, and "Malaysian Oak" actually is rubberwood from tropical rubber tree plantations. In addition, the colour, grain pattern, hardness, and luster of many imported woods differ from those of North American hardwoods.

Whatever the species chosen, the design authority must consult local manufacturers and suppliers in regard to availability and suitability.

.03 The following list of domestic and imported hardwoods and softwoods is provided for general information only.

8 • DOMESTIC (NORTH AMERICAN) HARDWOOD SPECIES

A number of North American hardwood species are used for flooring material. The following species are not in any order of preference or usage. Other species may also be used and the design authority must consult local manufacturers and suppliers in regard to characteristics listed herein.

.01 Ash (Fraxinus Americana) from North America. Other varieties are also available from Central and South America.

Appearance: Heartwood is light tan to dark brown and sapwood is creamy white. Similar to White Oak but more yellow.
Grain: Bold, straight, moderately open grain with occasional wavy figuring, and can have strong contrast in grain in plain sawn boards.
Hardness Rating: (Janka Table) 1230 or 4.7% softer than Northern Red Oak.
Durability: Elastic, hard, excellent shock resistance.
Workability:

Machining / Sawing: Good.
Fastening: Good holding; good resistance to splitting.
Sanding: Satisfactory.
Finishing: Stains well, no known finishing problems.

.02 American Beech (Fagus Grandifolia) / European Beech(Fagus Sylvatica) similar.

.1 General:FagusFsylvaticaFgrandifolia -
.2 Appearance:  Heartwood is reddish brown and sapwood is pale white.
.3 Grain:  Mostly closed, straight grain, uniform texture.  Coarser than European Beech.
.4 Hardness Rating:  (Janka Table) 1300 or 8% harder than Northern Red Oak.
.5 Durability:  Elastic, hard; excellent shock resistance.  Wears well, stays smooth when subjected to friction - popular for factory floors.
.6 Workability:

.a Machining / Sawing:  Good with machine tools, difficult to work with hand tools.
.b Fastening:  Good holding ability; has tendency to split.
.c Sanding:  Satisfactory.
.d Finishing:  No known problems.

.03 Yellow Birch (Betula alleghaniensis) / Birch (Betula spp.)

.1 Appearance:  Heartwood is light reddish brown tinged with red, and sapwood is creamy yellow (or pale white in yellow Birch).  Sweet birch has light coloured sapwood and heartwood is dark brown tinged with red.
.2 Grain:  Medium figuring, generally straight, closed grain with fine uniform texture. Occasional curly grain or wavy figure in some boards.
.3 Hardness Rating:  (Janka Table) 1260 or 2.3% softer than Northern Red Oak.
.4 Durability:  Hard and stiff, and very strong withgood crushing strength and shock resistance. It dries rather slowly with little degrade, but it has moderately high shrinkage, so is susceptible to movement in performance.
.5 Workability:

.a Machining / Sawing:  Good with machine tools; difficult with hand tools.
.b. Fastening:  N.
.c. Sanding: Satisfactory.
.d Finishing:  To known problems.

.04 American Black Cherry (Prunus serotina)

.1 General:  Prunus is a genus of 120 to 400 species that contain fruitwoods like cherry, plum, and almond.  The species are native to North America, Asia, Europe, and the Mediterranean region. All species look alike microscopically. The word prunus is the classical Latin name for the cherry tree.  Prunus serotina in North America includes American cherry, black wild cherry, cabinet cherry, chisos wild cherry, Edwards Plateau cherry, escarpment cherry, gila chokecherry, mountain black cherry, rum cherry, southwest choke cherry, southwestern chokecherry, wild black cherry, wild cherry, whisky cherry.

.2 Appearance:  Heartwood is light to dark reddish brown, lustrous; sapwood is light brown to pale with a light pinkish tone.  Some manufacturers steam lumber to bleed the darker heartwood colour into the sapwood, resulting in a more uniform colour.

.3 Grain:  Fine, frequently wavy, uniform texture.  True quarter sawn has distinctive flake pattern. Texture is satiny, with some gum pockets.

.4 Hardness Rating:  (Janka Table) 950 or 26.4% softer than Northern Red Oak.

.5 Durability:  , moderately hard. Usually considered too soft for an entire floor-mostly used for accents and borders.

.6 Workability:

Machining / Sawing: easily machined, turns well, and planes excellently with standard cutting angles.
Fastening: Nail / screw-holding ability is good, as is gluing, except where gum streaks are present.
Sanding: Satisfactory
Finishing: finishes smoothly, no known problems.

.05 American Cypress (Taxodium distichum)

.1 General:  Other names include Bald cypress, Red cypress, Yellow cypress, and Southern cypress. Cypress trees are conifers, but unlike most softwood, these are deciduous trees that shed foliage in the fall like hardwoods.  Although cypress is softwood, it grows alongside hardwoods and traditionally has been grouped and manufactured with hardwoods.

.2 Appearance:  S

.3 Hardness Rating:  (Janka Table)  1375 or 6.6% harder than Northern Red Oak.

.4 Durability:  .

.5 Workability:

.a Machining / Sawing:  .
.b Fastening:  Nails and screws very well.
.c Sanding: Easy / well.
.d Finishing:  Readily accepts finishes with no known problems.

.06 Elms:

General: Elm (Ulmusspp.) contains about 45 species native to Asia [11], Europe and the Mediterranean [6], South and Central America [7] and North America [7]. All species look alike microscopically and can be broken down into hard and soft elms.
Hard Elms:

Winged Elm(Ulmus alata) also cork elm, mountain elm, red elm, southern elm, wahoo, wahoo elm, water elm, whahoo, witch elm.
Cedar Elm(Ulmus crassifolia) also American red elm, basket elm, red elm, rock elm, small leaved elm, southern rock elm, Texas elm, water elm.
September Elm(Ulmus serotina) also Red elm.
Rock Elm(Ulmus thomasii) also Canadian rock elm, cliff elm, cork elm, corkbark elm, corky elm, corky barked elm, hickory elm, northern cork elm, northern corkbark elm.

3. Soft Elms:

American Elm(Ulmus Americana) also American soft elm, American weeping elm, American white elm, Florida elm, gray elm, gray hard elm, rock elm, springwood, soft elm, swamp elm, water elm, white elm.
Red Elm(Ulmus Rubra) also gray elm, Indian elm, it slips ooo-hoosk-ah, moose elm, red elm, red wooded elm, rock elm, slippery elm, soft elm, sweet elm.

.04 Red Elm:

General: A moderately heavy, hard, and stiff wood with excellent bending and shock resistance that is difficult to split because of its interlocked grain. It dries well with minimum degrade and little movement in performance.
Appearance: greyish white to light brown narrow sapwood, with heartwood that is reddish brown to dark brown in colour.
Grain: coarse texture. Grain can be straight, but is often interlocked.
Hardness Rating: (Janka Table) 1320 or 2.3% harder than Northern Red Oak.
Workability:

Machining / Sawing: fairly easy to work.
Fastening: nails, screws and glues well.
Sanding: sands well.
Finishing: stains to a good finish.

.07 Hickory and Pecan-Hickory (Carya spp.)

General: Hickories are an important group within the Eastern hardwood forests. Botanically they are split into two groups; the true hickories, and the pecan hickories (fruit bearing). The wood is virtually the same for both and is usually sold together. Hickory is the hardest, heaviest and strongest American wood. The density and strength of the hickories will vary according to the rate of growth, with the true hickories generally showing higher values than the pecan hickories. The wood is well‑known for its very good strength and shock resistance and it also has excellent steam‑bending properties. Extremely tough and resilient, quite hard and only moderately heavy. Wood can be difficult to dry and has high shrinkage.
Appearance: HickoryPecan heartwood is reddish brown with dark brown stripes; sapwood is white or creamy white with pinkish tones.
Grain: Hickory is closed, with moderate definition and somewhat rough-textured. Pecan is open, occasionally wavy or irregular.
Hardness Rating: (Janka Table) 1820 or 41.1% harder than Northern Red Oak.
Durability: Wood has a combination of strength, hardness, toughness and stiffness not found in other commercial wood species but is susceptible to bird peck and is rated as slightly or nonresistant to heartwood decay.
Workability:

Machining / Sawing: The heaviest of North American hardwoods, the hickories can be difficult to machine and glue, and are very hard to work with hand tools, so care is needed.
Fastening: Holds nails and screws well, but there is a tendency to split so pre-boring is advised.
Sanding: Difficult due to density, sanding marks may show
Finishing: Grain pattern welcomes a full range of medium‑to‑dark finishes and bleaching treatments.

.08 Hard Maple - Sugar Maple (Acer saccharum), Black Maple (Acer nigrum)

.1   General: Hard Maple is a hard and heavy wood with good strength properties; in particular it has high resistance to abrasion and wear. It also has good steam-bending properties.

.2   Appearance:  Heartwood varies from creamy white to light to dark reddish brown. Sapwood is pale to creamy white with a slight reddish brown tinge. The amount of darker brown heartwood can vary significantly according to growing region. Both sapwood and heartwood can contain pith fleck.

.3   Grain:  Generally closed, fine / subdued straight grain, with uniform texture, but occasionally may have quilted, fiddle back, curly or bird's-eye figuring. Figured boards often culled during grading and sold at a premium.

.4   Hardness Rating:  (Janka Table) 1450 or 12.4% harder than Northern Red Oak.

.5   Durability:  Dense, strong, stiff, often used in bowling alleys and sports floors.

.6   Workability: Dries slowly with high shrinkage, so can be susceptible to movement in performance. With care it machines well.

Machining / Sawing: Moderately difficult to work due to high density, carbide tooling recommended.
Fastening: Nailing good, fair resistance to splitting, glues satisfactorily. Pre-boring is recommended when nailing and screwing.
Sanding: Satisfactory to well.
Finishing: No known problems except it does not stain uniformly, although it can be stained to an outstanding finish and polishes well. Best in natural finish.

.09 Soft Maple - Red Maple (Acer rubrum), Silver Maple (Acer saccharinum). Other Names: Box Elder

General: In most respects soft maple is very similar to hard maple. Soft maple is often used as a substitute for hard maple or stained to resemble other species such as cherry. Its physical and working properties also make it a possible substitute for beech.
Appearance: Generally the sapwood is greyish white, sometimes with darker coloured pith flecks. The heartwood varies from light to dark reddish brown. The wood is usually straight-grained. The lumber is generally sold unselected for colour.
Hardness Rating: (Janka Table) Red Maple: 950 or 26.4% softer than Northern Red Oak / Silver Maple: 700 or 45.7% softer than Northern Red Oak.
Durability: Medium bending and crushing strength, and is low in stiffness and shock resistance.
Workability: Dries slowly with minimal degrade and there is little movement in performance, machines and turns well.

Machining / Sawing: Moderately difficult to work due to high density, carbide tooling recommended.
Fastening: Nailing / screwing and gluing satisfactory, fair resistance to splitting.
Sanding: Satisfactory to well.
Finishing: No known problems. It can be stained to an outstanding finish and polishes well.

.10 Mesquite (Prosopis glandulosa)

.1   Appearance:  Colour: Light brown to dark reddish brown.
.2   Grain:  High in character, with ingrown bark and mineral streaks.  Used in end-grain flooring blocks.
.3   Hardness Rating:  (Janka Table) 2345 or 82% harder than Northern Red Oak.
.4   Durability:  Dense and very strong.  Susceptible to termites and pinhole bores.
.5   Workability

.a Machining / Sawing:  Works easily with most tools.
.b. Fastening:  Pre-boring necessary for nailing.
.c Sanding:  Good with end grain requiring #16 grit paper to cut properly.
.d Finishing:  No known problems, finishes smoothly, does not take a high polish.

.11 Oak (Quercus spp.) - General Comments

General: Worldwide, the oaks (Quercus spp.) consist of 275 to 500 species that can be separated into three groups: the live or evergreen oak group, the red oak group (Erythrobalanus), and the white oak group (Leucobalanus). Species within each group look alike microscopically. The word quercus is the classical Latin name of oaks, said to be derived from Celtic words "fine" and "tree".
Abundance: Oaks are by far the most abundant species group growing in the Eastern hardwood forests. Red Oaks grow more abundantly than the white Oaks. The red Oak group comprises many species, of which about eight are commercial.

.1 Red Oak (Quercus Erythrobalanus)

Appearance: Heartwood is pinkish reddish brown and sapwood is lighter in colour (light brown to white) although both can be very similar (slightly redder than white). The wood is similar in general appearance to white Oak, but with a slightly less pronounced figure due to the smaller rays.
Grain: Mostly straight-grained, open, and slightly coarser (more porous) than white Oak. Plain sawn boards have a plumed or flared grain appearance; rift sawn has a tighter grain pattern, low figuring; quarter sawn has a flake pattern, sometimes called tiger Oak, tiger rays or butterflies.
Hardness Rating: (Janka Table) 1290 - the benchmark.
Durability: A hard and heavy wood with medium bending strength and stiffness and high crushing strength. It is very good for steam bending. Great wear resistance but less durable than White Oak.
Workability:

Machining / Sawing: Dries slowly and machines well; sawing is above average.
Fastening: Nailing and screwing are good although pre-boring recommended.
Sanding: Satisfactory, better than white Oak.
Finishing: Stains with a wide range of finish tones to a good finish with strong stain contrast, because of pores.

.2 White Oak (Quercus Leucobalanus / Quercus alba)

General: White Oak is impervious to liquids, and has been used extensively for ship timbers, barrels and casks. Tannic acid in the wood protects it from fungi and insects.
Appearance: Heartwood is a light to dark brown with some boards having a pinkish tint or a slight greyish cast. Sapwood is light in colour (white to cream).
Grain: Mostly straight-grained with medium to coarse texture, with occasional crotches, swirls and burls and longer rays and therefore more figure than red Oak. Plain sawn boards have a plumed or flared grain appearance; rift sawn boards have a tighter grain pattern and low figuring, and quarter sawn boards have a flake pattern, sometimes called tiger Oak, tiger rays, or butterflies.
Hardness Rating: (Janka Table) 1360 or 5.4% harder than Northern Red Oak.
Durability: More durable than red Oak, white Oak is a hard and heavy wood with medium bending and crushing strength, low in stiffness, but very good in steam bending. Great wear-resistance.
Workability:

Machining / Sawing: Wood dries slowly and machines and saws well.
Sanding: Satisfactory.
Fastening: Nails and screws well although pre-boring is advised. Since it reacts with iron, galvanized nails are recommended. Its adhesive properties are variable.
Finishing: Absorbs finishes more evenly than red Oak. Can be stained with a wide range of finish tones to a good finish. Does NOT bleach well.

.12 Sycamore (Platanus occidentalis) Other Names: Buttonwood, Plane tree.

General: The largest leaf of any tree native to North America, sycamore wood is classified as moderate in weight, hardness, stiffness, and shock resistance.
Appearance: Heartwood is light to dark brown and sapwood is white to light yellow. The wood has a fine close texture with interlocked grain that contrasts well with other species.
Hardness Rating: (Janka Table) 770 or 40.3% softer than Northern Red Oak.
Durability: New wood dries fairly rapidly, with a tendency to warp, moderate shrinkage, and little movement in performance and is resistant to splitting due to the interlocked grain.
Workability:

Machining / Sawing: Machines well, but high speed cutters are needed to prevent chipping. It turns well on the lathe and has good bending qualities.
Fastening: Glues well.
Sanding: Satisfactory.
Finishing: Stains, with care, to an excellent finish.

.13 Black Walnut (Juglans nigra), also referred to as American Black Walnut

Appearance: Heartwood is light to rich deep / dark chocolate brown occasionally with a purplish cast and darker streaks while sapwood is creamy white (nearly white to tan). The difference between heartwood and sapwood is great; some manufacturers steam the wood to bleed the darker heartwood colour into the sapwood. The wood develops a rich patina that grows more lustrous with age.
Grain: Generally straight-grained and open, but sometimes with wavy, curly or burled grain that produces an attractive and decorative figure. This species produces a greater variety of figure types than any other.
Hardness Rating: (Janka Table) 1010 or 21.7% softer than Northern Red Oak.
Durability: A strong / tough hardwood of medium density, with moderate bending and crushing strengths, low stiffness, good dimensional stability, and good steam bending classification. New wood dries slowly, and care is needed to avoid kiln degrade.
Workability:

Machining / Sawing: Works easily with hand and machine tools.
Fastening: Nails, screws, and glues well.
Sanding: Satisfactory.
Finishing: Holds stain very well for an exceptional finish and is readily polished.

9 • IMPORTED HARDWOOD SPECIES

.01 Brazilian Cherry or Jatoba (Hymenaea, courbaril) From Central and South America (not a cherry tree)

Appearance: Colour of sapwood is grey-white; heartwood is salmon red to orange-brown when fresh, and becomes russet or reddish brown when seasoned and often marked with dark streaks.
Grain: Mostly interlocked; texture is medium to rather course.
Hardness Rating: (Janka Table) 2350 or 82.2% harder than Northern Red Oak.
Durability: Dense and very strong, very resistant to heartwood decay, and dimensionally stable.
Workability:

Machining / Sawing: Easy to work, machine, and turn. Planes excellently with standard cutting angles. Saws cleanly but difficult due to high density, carbide tooling recommended.
Fastening: Nail / screw holding good, as is gluing, except where gum streaks are present. Due to hardness may require adjustment of angle of penetration and/or height.
Sanding: Well.
Finishing: Finishes smoothly. No known problems.

.02 Australian Cypress (Callitris glauca) Actually a pine tree (softwood)

Appearance: Colour: Sapwood is cream coloured; heartwood is honey-gold to brown with darker knots throughout.
Grain: Closed.
Hardness Rating: (Janka Table) 1375 or 6.6% harder than Northern Red Oak.
Durability: Excellent.
Workability:

Machining / Sawing: Good.
Fastening: Can be brittle, splits easily
Sanding: Satisfactory.
Finishing: No known problems

.03 Jarrah (Eucalyptus marginata) From Western Australia (a eucalyptus tree)

Appearance: Heartwood is pinkish to dark red, often a rich, dark red mahogany hue, turning a deep brownish red with age and exposure; sapwood is pale. Frequent black streaks with occasional ingrown grain.
Grain: interlocked or wavy. Texture is even and moderately course.
Hardness Rating: (Janka Table) 1910 or 48.1% harder than Northern Red Oak.
Durability: Excellent.
Workability:

Machining / Sawing: Difficult to work due to high density and irregular grain.
Fastening: Good.
Sanding: Well. Dust can stain fabric or wall coverings.
Finishing: Bleeding can occur (red) with some finishes

.04 Mahogany - Santos (Myroxylon balsamum) From Central and South America. Other varieties are also available from the same areas.

Appearance: Dark reddish brown colour.
Grain: Striped figuring in quarter-sawn selections, with even and very fine texture.
Hardness Rating: (Janka Table) 2200 or 78.3% harder than Northern Red Oak.
Durability: Excellent.
Workability:

Machining / Sawing: Moderately difficult to work due to high density, carbide tooling recommended.
Fastening: Nailing / screwing good.
Sanding: Well.
Finishing: No known problems.

.05 Merbau (Ipil, kwila Intsia spp) From South East Asia.

Appearance: Heartwood is yellowish to orange-brown when freshly cut, turning brown to dark red-brown upon exposure.
Grain: Straight to interlocked or wavy with coarse texture.
Hardness Rating: (Janka Table) 1925 or 49.2% harder than Northern Red Oak.
Durability: Excellent.
Workability:

Machining / Sawing: Moderately difficult to work due to high density, carbide tooling recommended.
Fastening: Good.
Sanding: Satisfactory to well.
Finishing: Wood stains black in contact with ferrous metals or moisture.

.06 Padauk (Pterocarpus soyauxii) From Central Africa

Appearance: Colour: Heartwood is reddish orange when freshly cut, turning to reddish and purple-brown or black over time. Sapwood is cream coloured. Very uniform.
Grain: Straight to interlocked, with coarse texture.
Hardness Rating: (Janka Table) 1725 or 33.7% harder than Northern Red Oak.
Durability: Excellent.
Workability:

Machining / Sawing: Well, carbide tooling recommended.
Fastening: Nailing good.
Sanding: Satisfactorily.
Finishing: Well, water-based finishes hold colour better, has a tendency to bleed.

.07 Purpleheart (Amaranth, Peltogyne spp) from Central and South America

Appearance: Colour: Heartwood is brown when freshly cut, turning to deep purple to purplish brown over time. Sapwood is lighter cream coloured.
Grain: Straight with medium to fine texture.
Hardness Rating: (Janka Table) 1860 or 44.2% harder than Northern Red Oak.
Durability: Very strong and dense.
Workability:

Machining / Sawing: Moderately difficult, carbide tooling recommended.
Fastening: Nailing good.
Sanding: Satisfactory.
Finishing: Well, water-based finishes hold colour better, has a tendency to bleed in some finishes.

.08 Rubberwood or Parawood or Heveawood (Hevea brasiliensis)

General: Rubber wood is a moderately heavy timber that is resistant to many fungal, bacterial and mould attacks and is used for manufacturing a wide range of products including wood flooring.
Appearance: Heartwood is whitish yellow when freshly cut which seasons to a pale cream colour, often with a pinkish tinge. Sapwood is not differentiated from the heartwood. It has a moderately course but even texture with an "absence" of dead knots, stains, fungi, sapwood and discolouration.
Grain: Very little (mostly straight to shallowly interlocked). Cross section shows vague concentric markings which resemble growth rings that combined with the large vessels visible to the eye, give the timber an attractive appearance.
Hardness Rating: (Janka Table) 933 or 27.7% softer than Northern Red Oak.
Durability: Shrinkage is low, making the dried timber very dimensionally stable. Moderate wood bending properties that after setting are very stable. Wood requires wood preservative chemical applied by vacuum pressure impregnation for effective protection from insect and termite infestation.
Workability:

Machining / Sawing: Easy to saw, crosscut, and to plane, turn and bore, producing smooth surfaces.
Fastening: Nailing good. Good gluing characteristics and high bonding strength. Compatible with almost all industrial grade adhesives.
Sanding: Satisfactory.
Finishing: Due to its light colour and very uniform structure, the wood can be stained easily to any desired colour and finish.

7. Substitution: Rubberwood is an effective substitute for Asian ramin, Meranti, Seraya, Agathis, Merbau, Kapur, Teak, African sapelli, Iroko, Kosipo & Obeche, Latin (South) American Imbula & Virola, Lauan, Nyatoh.

.09 Teak - Thia / Burmese (Tectona grandis)

Appearance: Heartwood varies from yellow-brown to dark golden brown, turning rich brown when exposed to sunlight. Sapwood is lighter cream coloured.
Grain: Straight, with a coarse uneven texture.
Hardness Rating: (Janka Table) 1000 or 22.5% softer than Northern Red Oak.
Durability: Strength values are similar to those of American Oak.
Workability:

Machining / Sawing: Sawn with moderate ease, carbide tooling recommended.
Fastening: Nailing good
Sanding: Clogs sanding paper.
Finishing: Some finishes have adhesion / drying concerns due to natural oils in the wood.

.10 Wenge or Panga-Panga (Millettia spp.)

Appearance: Heartwood is yellow-brown when freshly cut, turning dark brown to almost black with alternate layers of light and dark. Sapwood is yellowish-white and clearly demarcated from heartwood.
Grain: Straight when quartered; coarse texture.
Hardness Rating: (Janka Table) 1630 or 26.4% harder than Northern Red Oak.
Durability: Average.
Workability:

Machining / Sawing: Difficult; carbide tooling recommended.
Fastening: Good.
Sanding: Satisfactory.
Finishing: Some solvent-based stains do not dry well.

.11 Other Imported Hardwood Species

Cumaru (Dipteryx Odorata) from South America.
Eucaliptus (Eucaliptus Grandis) from Australia, South America, and Africa.
European Oak (Quercus Robur) from West and Central Europe.

10 • DOMESTIC (NORTH AMERICAN) SOFTWOOD SPECIES

The following North American softwood species are commonly used for the purposes of flooring:

.01 Douglas Fir (Pseudotsuga menziesii)

General: The genus Pseudotsuga contains about 7 species native to North America [2], and eastern Asia (China to Japan) [5]. The wood of pine can be separated microscopically into the white, red, yellow and the foxtail / pinyon pine groups.
Appearance: Heartwood is yellowish tan to light brown and sapwood is tan to white. Heartwood may be confused with that of Southern yellow pine. Radical colour change upon exposure to sunlight.
Grain: Normally straight, with occasional wavy or spiral texture. Nearly all fir flooring is vertical grain or rift sawn clear grade material.
Hardness Rating: (Janka Table) 660 or 48.8% softer than Northern Red Oak.
Durability: Durable but easily dented. May not be suitable for all flooring applications.
Workability:

Machining / Sawing: Harder to work with hand tools than soft pines.
Fastening: Nailing good.
Sanding: Satisfactory.
Finishing: May change colour with some finishing products, and care must be taken to avoid over sanding.

.02 Hemlock (Tsuga mertensiana) from North America (Pacific Coast)

General: Trees may contain wet wood and/or have ring shake.
Appearance: Heartwood is near white, sometimes with a purple tinge, while the sapwood is somewhat lighter.
Grain: Normally straight, with occasional wavy or spiral texture.
Hardness Rating: (Janka Table) 680 or 47.3% softer than Northern Red Oak.
Durability: Moderate in strength, hardness, stiffness and shock resistance, and slightly or non-resistant to heartwood decay.
Workability:

Machining / Sawing: Good.
Fastening: High screw and nail holding ability with a tendency to split, and satisfactory with respect to being glued.
Sanding: Sands smoothly.
Finishing: Satisfactory in taking stains, polish, varnish, and paint.

.03 Heart Pine - Antique (Pinus spp.)

Appearance: Heartwood is yellow after cutting and turns deep pinkish tan to warm reddish brown within weeks due to high resin content. Sapwood remains yellow, with occasional blue-black sap stain.
Grain: Dense, with high figuring. Plain sawn is swirled; rift or quarter sawn is primarily pinstriped. Curly or burl grain is rare.
Hardness Rating: (Janka Table) 1225 or 5% softer than Northern Red Oak.
Durability: Natural resistance to insects in heartwood, dense.
Workability:

Machining / Sawing: Good.
Fastening: Good.
Sanding: Use course paper for 1st sanding, may clog paper.
Finishing: Accepts surface and penetrating finishes, some stains tend to blotch.

.04 Southern Yellow Pine (Pinus spp.)

Appearance: Colour: Heartwood varies from light yellow/orange to reddish brown or yellowish brown; sapwood is light tan to yellowish white.
Grain: Closed, with high figuring; patterns range from clear to knotty.
Hardness Rating: (Janka Table) 690 or 46.5% softer than Northern Red Oak (Longleaf variety - 870 or 33% softer than Northern Red Oak.
Durability: Soft, fairly durable, not as resistant to scuff and dents as true hardwoods.
Workability:

Machining / Sawing: Good.
Fastening: Nailing good.
Sanding: Resin tends to clog sand paper, frequent paper changes are required.
Finishing: Using durable finishes can help minimize wear.

11 • IMPORTED SOFTWOOD SPECIES

.01 Imported softwood species include:

Pitch Pine / Heart Pine (Pinus Caribea/Oocarpa) from Caribbean/Central America.
Scandinavian Pine (Pinus Sylvestris) from Northern Europe.
Siberian Larch (Larix Siberica) from North-Central Russia.

12 • NON-WOOD SPECIES

.01 Bamboo

General: A grass not a hardwood, with more than 1,000 species-worldwide. An environmentally friendly product that helps preserve forests, Bamboo rejuvenates itself to maturity within 4 to 5 years.
Appearance: Naturally golden blond in colour with some varieties being stained, all having a unique distinctive pattern when made into flooring.
Hardness Rating: (Janka Table) 1630 or 26.4% harder than Northern Red Oak, and as hard as Hard Maple, 50% more stable and harder than Red Oak.
Treatment: during the manufacturing process, to prevent insect and mildew damage and to conform to both residential and commercial fire prevention standards.
Finish: most manufacturers produce this product pre-finished, ready for installation whether nail down or glued directly to a concrete surface, as it is a laminated (engineered) product.
Maintenance: same as most pre-finished products, light damp mop on occasion, with frequent sweeping and/or vacuuming.

For more information on Bamboo flooring refer to F03C1 - Bamboo Flooring.

13 • RELATIVE HARDNESS OR JANKA TABLE

.01 The following page on Janka hardness ratings is provided for information only. These and other ratings for species not listed must be verified from ratings provided by an appropriate independent (third party) testing agency. One source, amongst many, for this information is the Centre for Wood Anatomy Research of the U.S. Forest Service at www2.fpl.fs.fed.us

.02 The following Janka ratings are based on side testing samples of air-dried wood with a moisture content of 12%. The higher the number, the harder the wood is www.fpl.fs.fed.us

RELATIVE HARDNESS OR JANKA TABLE