flooring (k, 5), and in the tropics some staining and corrosion have been 
reported where the wood was in contact with iron (k, 5) • 
Durability 
Dipterocarpus species are rated as only moderately durable in exposed posi- 
tions (3M. For example, untreated railway ties in India lasted only k to 
5 years and house posts only about 1 year (21). Uoods from these species 
serve veil for interior work, but need preservative treatment if used in 
contact with the ground. They absorb preservatives readily', however, even 
with open-tank treatment {k, 5, lU) . The heartwood of apitong has been 
reported as resistant to dry-wood termites and powder post beetles (21). 
Defects 
Eeart checks or shakes, oil shakes, end splits, and surface checks sometimes 
occur or develop during seasoning of apitong (h, 5) • Except for the fact 
that the sapwood is not decay resistant and is attacked by beetles ( 12 ), 
these woods are comparatively free from defects in the logs. The logs, how- 
ever, should be removed from the woods as soon as possible after the trees 
are felled. Pes in sometimes exudes over the surface of sawn material and a 
dulling effect on the cutting edges of woodworking tools has been noted (12). 
Uses 
Apitong is used in construction where hard and heavy timber is required. 
Its uses include "posts above stumps," beams, joists, rafters, partitions, 
flooring, mine props, bridges and wharves, poles and railway ties 
(with preservative treatment), wagon beds, automobile framing, framing of 
barges and lighters, boats, carts, boxes, railroad cars, and medium-grade 
furniture (9, 21, 26). 
Availability 
Apitong is reported as one of the most abundant structural timbers found in 
good sizes in the Philippines. Volumes of 1,000 to 1^,000 board feet per acre 
have been reported (35). 
Structure 
Growth rings are not distinct. Pores tend to be rather evenly distributed, 
rounded in shape, open, and somewhat isolated, Pays are of two sizes (9) 
but appear to be few in number and narrow. Pes in ducts are diffusely scat- 
tered and surrounded by bands of parenchyma (l4, 26) . 
Report No. P1920 -5. 
