HENSOMASTIK® 5 KS fire retardant coating on cables

HENSOMASTIK® 5 KS fire retardant coating on cables

Waterproof fire-resistant coating on cables and cable ducts indoors and outdoors.


HENSOMASTIK® 5 KS is a water-impermeable fire-protection coating which can be used on horizontal or vertical cables and cable conduits indoors as well as outdoors. HENSOMASTIK® 5 KS reduces the heat exposure through ablation (release of water in a chemical reaction) in the event of fire, thus retarding an ignition and preventing the fire from spreading along the cables.

Product characteristics

  • Contains no solvents, APEO, halogens, borates or plasticisers
  • Water-impermeable in accordance with DIN 1048
  • Oil and petrol resistant
  • Weatherproof / UV resistant in accordance with DIN 53 384
  • Ageing resistant, mechanically stable
  • Flexible when dry even when thick layers have been applied
  • Temperature resistant to -40 °C when completely dry


  • Environmental product declaration No. EPD-RHG-20140204-IAA1-DE
  • Registration in the DGNB Navigator: CDDWRA


Further advantages of a cable coating with HENSOMASTIK® 5 KS:

Protection against UV radiation
Besides gamma and X-ray radiation, ionizing radiation, i.e. radiation that is so energetic that electrons can be released from an atom or molecule (ionization), includes as well as very short-wave UV radiation as a component of solar radiation. UV rays that penetrate the molecular chains of the sheath material of cables can break them down, causing accelerated aging and deterioration of the physical properties of the cable sheath. For example, when cables are used outdoors without protection, UV radiation can cause colours to fade and plastics to become brittle, causing them to lose elasticity and become brittle.

Degradation of the mechanical properties of the cable sheath can thus promote cracking, especially in cables exposed to weathering and movement. Cracks in the cable sheath can ultimately lead to water penetration, so that the serviceability of the cables is no longer given.

A fire protection coating made of HENSOMASTIK® 5 KS, which is weatherproof and UV-resistant in accordance with DIN 53 384, can slow or completely negate this effect. HENSOMASTIK® 5 KS is further impermeable to water in accordance with DIN 1048, resistant to oil and gasoline, and highly resistant to aging, remains mechanically resilient and flexible after drying, even with high coating thicknesses and extreme environmental conditions.

Reduced dimensioning of electrical conductors
Furthermore, a cable coating with the white HENSOMASTIK® 5 KS has a positive effect on the thermal cable load capacity calculation according to IEC 60287. This method takes into account, among other things, the absorption coefficient of solar radiation on the cable sheathing.

To make the plastics used in cables and conductors less sensitive to UV radiation, carbon black or coloured pigments are used that absorb UV radiation and convert it into thermal radiation. However, the conductivity of the metal cable cores decreases as the temperature rises. Protecting the cable sheath from direct solar radiation can thus enable lower-dimensioned conductors by correcting the temperature-dependent nominal cable values.

Longer service life – less resource consumption
While metallic cable components (conductors, sheathing) can be recycled and reused, cables contain large quantities of plastics, e.g. PVC, PA, PU, PE, PTFE (Teflon), rubber, silicones and XLPE. These components are usually incinerated for energy recovery or disposed of in landfills. In Europe, the recycling rate for copper is about 45%, while aluminium is recycled at only about 30%. Extending the service life of cables thus protects the environment and helps conserve resources.