Just to be clear

We are aware that Ulin is well known in Indonesia but less so in Europe and beyond. To help bridge that knowledge gap, we created a comparison chart that highlights Ulin’s specifications, numbers, and distinctive features.

Premium Hardwood Comparison (Metric)
Density (kg/m³)
Ulin
1,100
1,050–1,150
Ipé
1,075
1,050–1,100
Cumaro
1,000
960–1,050
Values shown in average at 12% moisture content
Janka Hardness (kN)
Ulin
12.7
~12.7 kN
Ipé
16.4
~16.4 kN
Cumaro
15.6
~15.6 kN
In practical terms when use for decking, flooring, construction etc.

Ulin feels harder to the touch and is more resistant to wear and abrasion (walking, dragging furniture) because of its density and silica.

Ipe Ipé is more resistant to denting from sharp impacts because of its toughness.
Durability Class (EN 350)
Ulin
Class 1
Extremely Durable
Ipé
Class 1
Very Durable
Cumaro
Class 1
Very Durable
Stability (Rating 1-5)
Ulin
Excellent
5/5
Ipé
Very Good
4/5
Cumaro
Moderate
3/5
Longer bar = More Stable (Less movement with humidity changes).

Ulin:Extremely stable due to its high density and interlocked grain. It moves very little.

Ipé: Very stable, but slightly more prone to movement than Ulin.

Cumaru: Known to be the least stable of the three. It has a high tendency to warp, twist, and check (crack) as it dries or reacts to moisture changes. This is a critical factor for decking gaps and fastener holding.
Expected Lifespan (Years)
Ulin
50+
50-75
Ipé
45
40-50
Cumaro
25
25–30
Estimates reflect typical outdoor decking performance. While all three are Class 1 (Very Durable), Ulin's superior resistance to marine borers and extreme decay allows it to outlast Ipé and Cumaro in harsh environments.
Ulin
Ipé
Cumaro