Lauan is one common name for lumber from a large number (over 120) of species in the Shorea genus. These trees are grown in Southeast Asia, including Malaysia, Indonesia, and the Philippines.
There are thousands of local names for these species, but from a lumber point of view, the species are divided into four groups, based on color and weight: dark red meranti, also called tanguile, (pictured) which is dark red and very heavy (over 40 pounds per cubic foot), light red meranti which ranges from pink to dark red in color and weighs 25 to 40 pounds per cubic foot, white meranti which is yellowish brown and weighs between 30 to 54 pounds per cubic foot, and yellow meranti which is yellow to brownish yellow and weighs 30 to 40 pounds per cubic foot. Other common market names are red lauan, Philippine mahogany and meranti.
A typical tree can reach heights of 200 feet and 6 feet in diameter. The stem is straight, so clear lumber is plentiful.
Much meranti has been imported into North America as Philippine mahogany plywood. At times, the low density of the species used in such plywood have given this name a low-quality inference. However, lauan varies greatly in quality and appearance, so generalizations are not accurate. The key for purchasing plywood and lumber is to use proper specifications to assure that you will receive the desired quality.
PROCESSING SUGGESTIONS AND CHARACTERISTICS
As stated, the density varies both between and within the four groups. Light red meranti lumber would weigh about 2.0 pounds per board foot; dark red about 2.7 pounds per board foot.
Drying and Stability
All lumber reaching North America would have been kiln dried before shipment. It would not be uncommon, however, to see final MCs between 10 to 12 percent MC, which is too wet for furniture, millwork, and cabinet uses in North America. It would be prudent to always check the incoming MC. Additional drying of anything over 8 percent MC is required to avoid manufacturing problems. A sophisticated kiln is not required for this final drying.
Shrinkage in drying is variable from species to species, ranging from 6 to 10 percent. Changes in size when the moisture changes are moderate, and vary from species to species, being more with the higher density species. As a rough rule, the wood will change 1 percent in size tangentially (across the width in a flatsawn piece of lumber) when there is a 3.5 percent MC change, and 1 percent radially with an 8 percent MC change.
Gluing and Machining
Gluing of the lighter weight species is excellent. The denser species require more care.
Machining is variable, but often is fairly good. The lightweight species often splinter on the end grain when sawn. Gum in some species will cause rapid gumming of tools and sandpaper. Silica in some species rapidly dulls tools and creates a risk of allergic reactions in some workers. Surfaces often are quite grainy, even with good machining.
The strength, as may be expected, varies greatly from species to species. For light red meranti, which has a low density, the ultimate strength (MOR) in dry lumber is 9500 psi, the stiffness (MOE) is 1.2 million psi, and the hardness is 460 pounds. For dark red meranti, the values are 12,700 psi, 1.8 million psi and 780 pounds. For comparison, red oak values are 14,000 psi, 1.8 million psi, and 1300 pounds.
Color and Grain
The wood tends to be fairly coarse grained, with many larger pores. Sometimes the pores have deposits in them that glisten. The color also varies from very light to fairly dark red, depending on the species. When purchasing meranti lumber, careful attention to the specification will be required to assure consistency of appearance and properties.