American sap gum

American gum is an important and diverse group of hardwoods, often undervalued and growing sustainably throughout the Eastern and particularly the South Eastern USA. Not to be confused with Australian gum (Eucalypt)

Latin Name

Liquidambar styraciflua

Other Common Names

redgum, sweetgum

gum_sap_big

American gum trees are large with straight trunks growing widely across the South Eastern USA.  There are several other, non-commercial, gums that also grow across the USA. 

FOREST GROWTH

FIA data shows U.S. gum growing stock is 714.6 million m3, 4.9% of total U.S. hardwood growing stock. American gum is growing 22.9 million m3 per year while the harvest is 11.7 million m3 per year. The net volume (after harvest) is increasing 11.2 million m3 each year. U.S. gum growth exceeds or is in balance with harvest in all the main producing states.

Alabama Arkansas Arizona California Colorado Connecticut District of Columbia Delaware Florida Georgia Iowa Idaho Illinois Indiana Kansas Kentucky Louisiana Massachusetts Maryland Maine Michigan Minnesota Missouri Mississippi Montana North Carolina North Dakota Nebraska New Hampshire New Jersey New Mexico Nevada New York Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Virginia Vermont Washington Wisconsin West Virginia Wyoming Average annual growth, m3 0 3.5K
Back to whole of U.S. 0-20K 20K-40K 40K-60K 60K-80K 80K-100K 100K-120K > 120K Average annual growth, m3 0 200K
-15K -10K -5K 0 5K 10K 15K 20K 25K GROWTH AND REMOVALS, 1000 m³ -10K -9K -8K -7K -6K -5K -4K -3K -2K -1K 0 1K 2K 3K 4K 5K 6K 7K 8K 9K 10K GROWTH AND REMOVALS, 1000 m³ -2000 -1750 -1500 -1250 -1000 -750 -500 -250 0 250 500 750 1000 1250 1500 1750 2000 GROWTH AND REMOVALS, 1000 m³ -300 -200 -100 0 100 200 300 400 500 GROWTH AND REMOVALS, 1000 m³ Removals 0 Growth 0 Net growth 0
0 200K 400K 600K 800K 1M 1.2M FOREST VOLUME, 1000 m³ 0 40K 80K 120K 160K 200K 240K 280K 320K 360K 400K 440K FOREST VOLUME, 1000 m³ 0 10K 20K 30K 40K 50K 60K 70K 80K 100K FOREST VOLUME, 1000 m³ 0 4K 8K 12K 16K 20K FOREST VOLUME, 1000 m³ Forest volume 0

LCA Tool


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The replacement rate is calculated from total U.S. annual increment of the specified hardwood species derived from the U.S. Forest Service Inventory and Analysis (FIA) program and assumes that 2m³ of logs is harvested to produce 1m³ of lumber (i.e. 50% conversion efficiency). The rapid rate of replacement is due to the very large volume of hardwood trees in U.S. forest.

American gum is available as sawn lumber and veneer in a variety of grades and sizes. It is usually sold as sapgum with no colour specification. Under NHLA Grading Rules each clear cutting must have one red (heartwood) face. When sorted for colour redgum (majority heartwood) is much more limited in availability. Lumber is more likely to be available in thinner stock (4/4” & 5/4”) and may be more limited in export markets.

Gum has a fine uniform texture, but has irregular grain, usually interlocked, often with an attractive grain figure. The sap of gum tends to be wide and is white to light pink in colour, whereas the heartwood is reddish brown, typically with dark streaks.

Mechanical Properties

The wood of gum is only moderately hard to soft, stiff and heavy, but has low steam bending classification. The wood is close grained.

  • 0.62

    Specific Gravity (12% M.C.)

    689 kg/m3

    Average Weight (12% M.C.)

    13.40%

    Average Volume Shrinkage (Green to 6% M.C.)

    114.457 MPa

    Modulus of Rupture

    13,859 MPa

    Modulus of Elasticity

    56.332 MPa

    Compressive strength (parallel to grain)

    5,604 N

    Hardness
Oiled
gum_sap_oiled
Un-oiled
gum_sap_unoiled
  • Gum is easy to work with both hand and machine tools. It nails, screws and glues well, takes stain easily and can be sanded and polished to an excellent finish. Gum dries rapidly with a strong tendency to warp and twist. It has a large shrinkage and is liable to movement in performance. 

     
  • The wood is rated as non-resistant to decay. The heartwood is moderately resistant to preservative treatment, but the sap is permeable.

Main uses are cabinet making, furniture and furniture parts, doors, internal joinery and mouldings. Gum has been used and stained, as a substitute for walnut or mahogany.

Mouldings
Furniture
Doors
Cabinets