What is Bitumen 105/35?
Bitumen 105/35 is the premium flexible grade within the 105-series, combining the ultra-high softening point of 105–115°C with a moderate penetration of 30–40 dmm.
This is an exceptionally demanding specification to achieve: most oxidized bitumens at 105°C+ softening point exhibit very low penetration (10–20 dmm). The 105/35 grade is produced through a specialised air-blowing process that achieves the high softening point while retaining significantly higher flexibility than typical 105-series products.
This unique combination makes Bitumen 105/35 the preferred choice for industrial membrane manufacturers who need a base bitumen that delivers the highest available softening point while maintaining enough flexibility for membrane processing, handling, and performance at low temperatures.
It is also used in specialist heavy-duty waterproofing systems for industrial structures where both extreme heat and structural movement resistance are simultaneously required.



