About the Tree

Black Locust, Robinia pseudoacacia, a tree with many names, but with the same environmental attributes.

Decay resistance table

Grouping of some domestic and imported woods according to average heartwood decay resistance

Table taken from Wood Handbook: Wood as an engineering material- General Technical Report 113- USDA Forest Service

Domestic

Resistant or very resistant Moderately resistant Slightly or nonresistant
Baldcypress, old growth
Baldcypress, young growth
Alder, red
Catalpa
Douglas-fir
Ashes
Cedar
Larch, western
Aspens
Atlantic white
Pine, slash, old growth
Beech
Eastern redcedar
Pine, longleaf, old growth
birches
Incense
Tamarack
Buckeye
Northern white
Pine, eastern white, old growth
Butternut
Port-Orford
/
Cottonwood
Western redcedar
Elms
/
Yellow
Basswood
/
Cherry, black
/
Firs, true
Chestnut
/
Hackberry
Cypress, Arizona
/
Hemlocks
Junipers
/
Hickories
Locust
/
Magnolia
Black a
/
Maples
Honeylocust
/
Pines (other than those listed) b
Mesquite
/
Spruces
Mulberry, red a
/
Sweetgum
Oaks, white b
/
Sycamore
Osage orange a
/
Tanoak
Redwood, old growth
/
Willows
Sassafras
/
Yellow-poplar
Walnut, black
/
/
Yew, pacific
/
/

Imported

Resistant or very resistant Moderately resistant Slightly or nonresistant
Aftotmosia (Kokrodua)
Andiroba
Balsa
Angeliquea a
Avodire
Banak
Apamate (Roble)
Benge
Cativo
Azobea a
Bubinga
Ceiba
Balata a
Ehie
Hura
Balau b
Ekop
Jelutong
Courbaril
Mahogany, African
Meranti, light red b
Goncola alves a
Meranti, dark red b
Meranti, yellow b
Greenheart a
Mersawa b
Meranti, white b
Ipe (lapacho) a
Sapele
Obeche
Iroko
Teak, young growth
Okoume
Jarrah a
Tornillo
Parana pine
Kapur
/
Ramin
Karri
/
Sande
Kempas
/
Sepitir
Lignumvitae a
/
Seraya, white
Mahogany, American
/
/
Manni
/
/
Purpleheart a
/
/
Spanish-cedar
/
/
Sucupira
/
/
Teak, old growth a
/
/
Wallaba
/
/

a.) Exceptionally high decay resistance.

b.) More than one species included, some of which may vary in resistance from that indicated.

Black Locust

The Black Locust, also known as, Robinia pseudoacacia, Robinia, Acacia, False Acacia, Salcam, is native to the United States but is plentiful globally. With its fast and easy growth habit, the tree’s ability to sprout new shoots by underground stems makes Black Locust a sustainable hardwood. The tree’s deep root system helps control erosion and aids in rejuvenating soil as Black Locust is a nitrogen-fixing species. As a legume, its seed pods have the ability to fix nitrogen in the soil.

Durability

The wood is dense, durable, and resistant therefore ideal for a wide variety of outdoor applications. Black Locust’s qualities are due to the presence of tyloses and extractives. Tyloses are plant tissues that block cell vessels making them watertight. Extractives are compounds with anti-fungal properties found outside the cell wall of Black Locust that foster water resistance. If properly dried, it has excellent dimensional stability and minimal shrinkage. Black Locust has an extensive history of projects that document its durability.

Natural Alternative

Black Locust is a sustainable alternative to endangered tropical hardwoods, chemically treated lumber, and decay-prone woods. The harvesting of rainforest tropical hardwoods is unsustainable. Black Locust serves as an alternative to chemically-treated lumber, which is treated with a wide variety of Red List chemicals. Chemically-treated lumber lasts a fraction of the lifetime compared to Black Locust. Black Locust is an organic product- it does not require treatment or finishes to increase its longevity.

Characteristics

As Black Locust weathers, it develops a silvery-gray patina. The color is a result of natural weathering: U.V. rays, rain, snow and oxygen. There is not a known finish to eliminate U.V. deterioration for Black Locust or other wood species, U.V. wood treatments will only delay the natural patina of the wood. One of Black Locust’s distinct characteristics is its ability to accept stain or paint.

Premium Grade

The grades are based on the percentage of clear, defect-free wood in the board. With Premium Grade, each piece is individually inspected to ensure premium quality, durability and appearance. Visually, Black Locust is known for its knots, mineral streaks, checks, minor grub holes, and bark insertions. To ensure superior appearances, only the most appealing pieces qualify as Premium Grade. Sound included knots, 3″ in diameter and less, minor mineral streaks and small bark insertions are admitted to highlight characteristics of the Black Locust species. Checks less than 1/12th of the board length are also admitted.

Landscape Grade

With landscape grade, each individual piece of Black Locust is carefully inspected to ensure quality and durability. Visually, Black Locust is known for its knots, mineral streaks, checks, and bark insertions. All sound knots are admitted in this grade. All other characteristics that do not affect the durability of this product are also admitted — surface checks, mineral streaks, bark insertions, and grub holes. A popular product, without the premiere price.

Site Furnishing Grade

Black Locust Lumber produces a unique grade for the site furnishing industry. Please contact a Black Locust specialist for more information.

Is Black Locust wood valuable?

Black Locust wood is valuable because of its exceptional durability of 50+ years and certifiable sustainability. Black Locust wood is naturally rot-resistant and has antifungal properties. Black Locust is a hardwood that keeps its attractive appearance without the help of chemicals or oils. No maintenance is required.

Is Black Locust harder than oak?

Black Locust wood is harder than White Oak. We measure hardness of wood with the Janka Hardness scale: the higher the number the tougher the wood. Black Locust wood’s Janka hardness scale is 1,700 lbf (7,560 N) compared to White Oak Janka hardness scale of 1,360 (6,000 N).

Is Black Locust a hardwood?

Black Locust wood is a hardwood with a Janka hardness scale of 1,700 lbf (7,560 N).

Is Black Locust wood toxic?

Black Locust wood is not toxic, however, just like any other tree it can trigger allergies. Some people are allergic to the roots or the bark of Black Locust wood.
Translate »
error: © Black Locust Lumber

Declare Label

Manufacturers Self Declaration

Thank you!

Thank you for joining our journey to a sustainable and innovative future!

Download Construction manual

Download ProFlow™ Permeable Paver
Installation Manual