Thin film intumescent coatings

Intumescent coatings, shown below, are paint like substances which are inert at low temperatures but which provide insulation by swelling to provide a charred layer of low conductivity materials at temperatures of approximately 200-250°C. At these temperatures the properties of steel will not be affected.

 

The principal advantages are:

Aesthetics - the thin coating allows the shape of the underlying steel to be expressed.

Finish - attractive, decorative finishes are possible.

Application - complex details are easily covered.

Servicing - post-protection fixing is simplified.

The principal disadvantages are:

Cost - typical application costs are higher than sprays although costs have decreased in recent years.

Application - is a wet trade which requires suitable atmospheric conditions during application and precautions against overspray.

Limited Fire Resistance Periods - Most intumescent coatings can traditionally provide up to 60 minutes fire resistance economically. Improvements in technology in recent years have reduced coating thicknesses considerably and intumescents are increasingly competitive in the 90 minute market also. A limited number of intumescent coatings can achieve 120 minutes fire resistance.

Over the past decade intumescent coatings have come to dominate the passive fire protection market in the UK.