Material properties

GRÖMO manufactures roof drainage accessories in five different materials with nine different surfaces. Only European vendors are used as suppliers. This guarantees high quality in the raw material, and is a prerequisite for the high quality standards of GRÖMO.


Zinc has been used since ancient times as a component of brass. Europeans discovered the beneficial qualities of the metal in the 17th century. Thanks to its corrosion resistance, zinc is excellent for roof drainage and is always finding new areas of application - not least because it can be recycled so well.


Overview of properties and advantages:

  • Natural material 
  • Can go long periods without maintenance or cleaning due to the material’s self-cleaning nature thanks to natural ageing and contact with rainwater
  • Appearance improves over time due to natural weathering process 
  • Extremely long lifespan due to corrosion resistance and formation of a bonded, non-toxic protective layer when exposed to atmospheric weathering
  • Natural erosion very low
  • UV-resistant
  • Environmentally friendly
  • 100% recyclable 
  • High formability 
  • Easy to use

Melting point: 420 °C
Length variation at 100 K: 2,2 mm/m
Density: 7,20 kg/dm³

Surface weight

Assembly of metals