Fire and corrosion protection in one with Sika Unitherm

Passive fire protection is a vital component of any fire safety strategy for buildings. Built into the structure, it safeguards people's lives and limits the financial impact of damage to buildings and their contents. Sika provides comprehensive solutions for fire resistant construction in tunnels, commercial and residential buildings and in particular steel structures. Fire resistant coatings for load bearing structures are possible with Sika solutions such as Sika Unitherm Platinum.

Steel Structure Outside a Building in the evening
  Man Applying Fire Resistant Coating on a  load-bearing structure


Unlike wooden constructions, steel doesn’t burn. But effective fire protective is nonetheless critical here as well. When exposed to extreme heat levels, steel loses its load-bearing capacity and becomes unstable. This puts buildings at risk of collapsing.

Fire protective coatings from Sika extend the fire resistance rating of steel structural components to up to 150 minutes, compared with just a few minutes when left unprotected material. A coating thickness with just a few millimeter is sufficient to achieve this. The function, profile, thickness and material of the steel parts are decisive for the required structure and the application of the fire protective coating.

Fire and Corrosion Protection with Sika Unitherm Platinum

SIKA® UNITHERM® coatings provide corrosion AND intumescent fire protection for internally or externally exposed structural steel.

Sika® Unitherm® Platinum is a solvent-free, 100 % solids, 2-pack, modified epoxy based intumescent fire protection coating for internally or externally exposed structural steel, where it provides highest durability and combined corrosion protection (up to ISO 12944, corrosivity category C5) and fire protection (up to R90).exposed structural steel.

It is easily applied with standard airless spray equipment, requires no reinforcement, cures rapidly to a very tough and damage resistant finish, ready for handling and transport at the next day. Solvent-free according to Protective Coatings Directive of German Paint Industry Association (VdL-RL 04).

Allan Hunter

Market Field Manager - Flooring & Coatings

Any questions? Give me a call or email!

Function and Chemistry of Fire Protective Coatings

Although steel constructions do not burn, very high temperatures can cause them to lose their load-bearing capacity and thus their static stability within a few minutes. The functional principle of fire protective coatings is based on a specific, very complex chemical product composition.

Due to the thermal energy of the fire, the bonding agent begins to soften at the surface and is then swelling by the gases produced by an integral foaming agent to form a foam. The originally millimetre-thin coating converts into a centimetrethick, micro-porous insulating foam that insulates the substrate against heat.


Combination of Protection and Aesthetics

Circular or rectangular hollow sections are most frequently chosen for their visual appearance.

Sika® fire protective coatings allow the unrestricted protection of such components without impairing their visual appearance. In addition, a broad range of decorative finishes will also enhance the appearance of the structure purposefully as a supplementary design element.

Graph comparing fire resistance of steel: uncoated vs. Sika Unitherm Coat