FRED fire retardant intumescent paint 10kg tin – Warringtonfire tested Class A2-S1,D0 coating for timber and spray foam

Intumescent Paint Explained: How Fire Retardant Coatings Protect Timber and Spray Foam

Intumescent paint looks like ordinary paint until the moment it matters: in a fire, it swells to many times its thickness, forming an insulating char layer that shields the material beneath from heat. For timber structures and spray foam insulation — two of the most fire-vulnerable materials in modern construction — it's one of the most effective protections available.

FRED fire retardant intumescent paint 10kg tin, Warringtonfire tested to Class A2-S1,D0 for timber and spray foam

How Intumescent Coatings Work

The coating contains components that react at high temperature: an acid source, a carbon source and a blowing agent. Around 200–250°C these react together and the coating expands into a thick, stable foam char. That char slows heat transfer dramatically, buying the structure time — time for occupants to escape and for fire services to respond.

Burn test demonstration showing a wall treated with FRED flame retardant paint resisting fire exposure

What Does Class A2-S1, D0 Mean?

Fire classifications under EN 13501-1 describe how a product behaves in fire:

  • A2 — limited combustibility (the second-highest classification possible)
  • S1 — little or no smoke production
  • D0 — no flaming droplets

Smoke and burning droplets kill more people than flames — a coating that controls all three is doing the whole job.

Where You Need It

  • Spray foam insulation — exposed foam is a known fire risk; many building control bodies and insurers require a thermal barrier coating over it
  • Exposed timber — beams, posts, cladding and mass timber structures
  • Lofts and plant rooms — where insulation or structure would otherwise be exposed

FRED: Fire Protection You Can See

FRED Fire Retardant Coating is our Warringtonfire-tested intumescent paint, rated Class A2-S1,D0, designed for timber and spray foam. It applies by spray, roller or brush and comes in white or orange — the orange version makes it instantly visible to building inspectors that the protection is in place.

Warringtonfire logo – the independent fire testing laboratory that tested FRED fire retardant coating

FRED works alongside our airtightness systems: Passive Purple itself carries a BS Fire Class C rating (and Passive Purple X achieves Class B), so your airtight layer contributes to fire safety rather than undermining it.

Shop intumescent paints → or ask us about your specification.

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