Ironwood Vs Chengal

Two of the most popular natural wood species commonly used in South East Asia, for woodwork construction such as trellises and decking, are Chengal and Iron Wood.

Home owners and developers, before selection of wood, are likely to compare the characteristics between the two. However, there is still lack of credible resources to support the decision.

Let's look at both the pros & cons:

Density / Hardness

Both Chengal and Iron Wood are naturally hard and heavy. Such characteriestics make them suitable for all forms of heavy construction such as decking and marine construction. Ironwood (835 ~ 1185 kg/m3 air dry) has relatively higer density level than Chengal (915 ~ 980 kg/m3 air dry). Althougn both wood species have considerable high surface hardness, the tendency of forming hairline cracks are relatively common compared to softwood such pine trees. However, the owner needs to understand that hairlines on the wood surfaces are natural.

Natural Durability

According to Malaysian Timber Council (MTC) , both ironwood and chengal are naturally durable and have high resistance to termite attacks and fungi infestation. However, the owner needs to understand that young chengal timber, that is not treated or kiln dry properly, can only last about 9 years under sever environmental conditions. Hence, upon selection of wood materials, the home owners will need to get the right chengal wood materials from credible vendors. 

Forest Logging & Cost Pertaining to Health

According to the IUCN Red List of Threatened Species, Chengal is already classified as a vulnerable species found mostly in proctected areas in Malaysia. Iron Wood, on the other hand, which has about 27 species worldwide, is considered to have moderate level of supply to date. Hence, in view of protecting the trees in the global forests, using of iron wood and matured chengal is preferred. On another medical research report from  Tan Tock Seng Hospital, it is concluded that exposure to chengal wood dust can lead to occupational asthma (OA) and possibly rhinitis. Therefore, care should always be emphasized during any restoration of chengal woodwork.

Boring Defects on Chengal

"Small pin-holes, caused by ambrosia beetles boring into the living trees, are a common and characteristic defect of chengal."

(Sources: Malaysian Timber Council online report from woodwizard.my)

Such defect only occur when chengal timber is still young. When chengal timber is seasoned or matured, the ambrosia beetle will die. Hence, this is one of the main reasons why selection of matured chengal timber is important. As for iron wood, such defect is not possible.

In summary,

Both iron wood and chengal has their pros and cons. The owner or developer needs to understand and accept the natural characteristics of the different types of natural wood. By having a deeper understanding for chengal and iron wood, the owners can therefore make a better decision.

For the new wood decking owners, who feel that there is a need for a product warranty on natural wood just in case any defects occur, the owners can consider eco wood decking such as Accoya® wood which has a 50 years warranty on above ground projects and 25 years warranty on in ground projects.