Apitong, Keruing from Southeast Asia and Angelim Pedra from Brazil | Article Summary

This report discusses the similarities and differences between industry-leading Apitong, Keruing from Southeast Asia and Angelim Pedra from Brazil for use in the truck trailer industry. Both wood species are excellent choices for use as truck trailer flooring.

Background on Apitong, Keruing in Truck Flooring Applications

Asian Apitong has been the traditional wood of choice for flatbed truck flooring for at least 25 years. As standard flatbed flooring, Apitong is usually used as solid, plank flooring. Most commonly in a shiplap form, this flatbed flooring will typically vary from 1-1/8” to 1-3/4” in thickness with widths typically 5” or 7”. Solid shiplap flooring is typically used in lightweight flatbed trailers where product weight, durability, strength and price are the major concerns for manufacturers.

In heavy duty, drop deck trailers, manufacturers usually use larger sizes, from 1-1/2” (also known as 6/4) to 4” in thickness and wider widths, 8”, 10” and 12” being most common. Strength and durability are major issues in heavy duty trailers, but too hard can be a problem as well. The lumber is typically installed without surfacing, as rough material, and the decking must provide enough grip for heavy equipment such as skidders and bulldozers to drive up onto the flatbed.

Lengths are an important factor in selecting solid hardwood truck flooring. Tropical hardwoods will typically average at least 12-14’ in length. Splices must occur on cross members, which are typically between 12” and 24” center to center. One US manufacturer is finger jointing solid planks up to 53’ in length so that trailer manufacturers do not need to deal with random length boards; the average length of the planks before finger jointing is around 12’.

Do not confuse solid plank flooring with laminated truck flooring (LTF). LTF is strictly used in dry van trailers and is not able to withstand exterior exposure. The LTF market is substantially bigger than the solid plank flooring market; mixed light hardwoods from Southeast Asia and domestic Red Oak and the main species used in LTF. Typically the LTF manufacturers will use 5/4 or 6/4 x R/W raw material, S2S and straight line rip the material, and then they will cut hook joints on the ends of the strips. These strips are then laid up into a continuous panel that is edge glued together. LTF is generally run 12” wide with a shiplap and can be made as long as 53’.

Apitong typically comes from Indonesia and Malaysia. It is imported into the United States as both rough material and as finished product. Shipping from Southeast Asia is done by containers and by break bulk vessels.

Stength and Durability Characteristics of Typical Trailer Flooring Woods

Below is a table comparing the various types of wood that may be used in the trailer flooring industry:

SPECIES Approximate Weight per MBF at 10% MC Modulus of Rupture (psi) Modulus of Elasticity (1000 psi) Maximum Crushing Strength (psi) Side Hardness (lbs) Compression Perpendicular (psi) Shear (psi)
Purpleheart 4,800 21,300 2,420 11,380 2,060 1,910 1,830
Tatajuba 4,500 20,050 2,580 11,560 1,730 NA NA
Apitong 4,600 19,900 2,070 10,500 1,270 NA 2,070
Angelim Pedra 4,400 17,600 2,050 8,990 1,720 A 2,010
White Oak 4,200 15,200 1,780 7,440 1,360 1,070 1,360
Red Oak 3,900 14,300 1,820 6,760 1,070 1,010 1,780
Southern Yellow Pine 3,100 14,200 1,880 7,750 750 890 1,490
Douglas Fir 2,700 12,400 1,950 7,230 710 800 1,130

US Dept. of Agriculture Handbook No. 207
US Dept. of Agriculture Handbook No. 72, pp 4-24

When evaluating the suitability of particular species, one must consider the various strength factors, the hardness and the weight of the specie.

The softwoods listed above are not hard enough or strong enough for use in all but the lightest duty flatbed trailers. Southern Yellow Pine and Douglas Fir are used in consumer grade utility trailers and in some lightweight low-cost applications, but they both have minimal use in flatbed trailers.

At the other end of the spectrum, Purpleheart is the heaviest and hardest of all the species typically used on flatbeds. It is an excellent choice for heavy duty drop deck trailers, but it is more difficult to drill and cut due to its hardness. Tatajuba is very close to Purpleheart in most characteristics but is reported as very difficult to dry and has a tendency to twist and check easily.

The two Oak species are listed for comparison purposes only. Oak is just not available in long enough lengths and in a good enough grade for use in flatbed applications.

As shown, Angelim Pedra and Apitong are extremely close in strength characteristics and weight. Typically, Angelim is about 5% lighter, saving around 100 pounds on a typical 48’ long flatbed trailer with a 1-3/8” deck.

Another important factor to consider is the stability of the wood species. Below is table comparing shrinkage from green lumber to 0% moisture content, or maximum shrinkage. Because wood does not shrink or expand uniformly, one should consider the difference between radial and perpendicular shrinkage; if the differential is high then the wood will be less stable.

Moisture Related Shrinkage, Expansion and Stability Characteristics

SPECIES Shrinkage Radial to Grain Shrinkage Perpendicular to Grain Differential Shrinkage Volumetric Shrinkage Stability Ranking
Purpleheart 3.2% 6.1% 2.9% 9.1% #1
Tatajuba 5.2% 6.6% 1.4% 10.2% #3
Apitong 5.2% 10.9% 5.7% 14.7% #7
Angelim Pedra 4.4% 7.1% 2.7% 10.2% #2
White Oak 5.6% 10.5% 4.9% 16.3% #8
Red Oak 4.0% 8.6% 4.6% 13.7% #6
Southern Yellow Pine 4.0% 7.2% 3.2% 11.9% #4
Douglas Fir 4.8% 7.6% 2.8% 12.4% #5

US Dept. of Agriculture Handbook No. 207
US Dept. of Agriculture Handbook No. 72, pp 3-15

While these shrinkage and expansion figures do indicate relative stability, each species listed has variability within itself. Purpleheart may be the best choice in terms of stability but commercial prices have risen significantly during the late 1990's and early 2000's - as of the last update of this article, 2013, we have found that Purpleheart is no longer a commercially viable choice. Tatajuba and Angelim Pedra, which are also both from South America like Purpleheart have also risen in price in recent years relative to Apitong.

Durability Ratings Typical Trailer Flooring Hardwoods

Being able to withstand exposure to the elements for 10 to 20 years is what is required of a wood used for flatbed trailer flooring. The published data is limited for most tropical hardwoods. Durability tests have been performed which rate a couple of the common species used in truck trailer applications.

SPECIES Test Period in Months Avg. Loss in Weight, Five Different Fungi Class of Resistance
Purpleheart 8 Negligible Very Resistant
Apitong 8 19.8% Not Resistant

“The Empire Forestry Journal”, volume 18, 1938 by Legat and Milward

Most of the guides to tropical hardwoods summarize the durability of each specie based on published lab results. For example, here are the statements from the USDA Tropical Timbers of the World publication:

SPECIESComments
Purpleheart Heartwood is rated as highly durable in resistance to attach by decay fungi; very resistant to dry-wood termites; but little resistance to marine borers.
Angelim Pedra In laboratory tests heartwood was rated very durable to durable upon exposure to a white-rot and durable in resistance to a brown-rot fungus. Exposure tests indicate the heartwood is only moderately resistant to marine borers.
Keruing Durability varies with specie, generally classified as moderately durable, but heartwood is susceptible to termite attach. Though silica content may be high, resistance to marine borers is erratic.

US Dept. of Agriculture Handbook No. 207

Some Facts about the Availability and Supply of Angelim Pedra

Angelim Pedra is clearly an acceptable substitute for Apitong or Keruing and it gained an amazing market share since it was first promoted for truck trailer use in the mid 1990's. However, market dynamics have changed significantly.

The availability of Angelim Pedra was excellent for a number of years, with sources throughout Northern Brazil and adjacent countries. Many US based companies were importing Angelim Pedra in the late 1990's and early 2000's with volumes in excess of 2000m3 per year.

Angelim Pedra is one of the major species available in most logging concessions in the Amazon region. The logs have practically no sap and are generally very large without any rot or shake all the way to the core of the tree. The yield from and Angelim Pedra log is among the highest of any of the tropical trees. The trees are exceptionally tall and therefore longer lengths or fixed lengths are much easier to achieve than in other species.

Due to its somewhat limited uses, Angelim Pedra has not been subject to the excess market demand such as Brazilian Cherry for interior flooring or Ipe for exterior decking. Because of the “pedras”, which translates as stone in Portuguese, Angelim Pedra has seen limited demand for decking or interior uses. It has been used for paint grade applications such as doors and windows in the European market, but it is slightly heavy and difficult to manufacture for these uses. In Brazil, Angelim Pedra is used as an inexpensive alternative for ceiling, flooring, furniture and interior trim. It has also been used as railroad ties or sleepers along with a number of other low value species such as Angelim Vermehlo and Piquia.

Due to its proximity to the United States, South America is able to efficiently ship material with weekly container and monthly break bulk shipments. Finished products shipped by container can reach just about any destination in the United States or Canada within four weeks from date of shipment.

We expect market conditions to continually change and while the balance as of 2013 strongly favors Apitong as the best commercial choice, we anticipate the Angelim Pedra will once again become the favored choice at some point in the future.

Factors Regarding Apitong Supply from Southeast Asia

The recent shift away from Angelim Pedra began in 2008-2009 as the Brazilian currency strengthed relative to the US Dollar and Southeast Asian currencies. Tropical timber exports from Brazil dropped by over 80% from 2007 through 2012. Environmental factors and currency issues were the major reasons for this drop in export volume.

Southeast Asia, as compared to Brazil, has a history of a much more stable environmental policy. There has been less over-harvesting and less pressure from alternative agricultural uses as well. Both Indonesia and Malaysia have well-established environmental regulations which have resulted a steady supply of material into the market.

Please do not hesitate to give us a call should you have any questions or comments regarding this article. We can be reached at 1-855-APITONG.