Spray Foam Fire Protection: Ireland Guide

Spray foam insulation delivers outstanding thermal performance in commercial and industrial buildings — but like any organic insulation material, it must meet strict fire safety standards before it can be used in occupied structures. In the Republic of Ireland, this means meeting Part B of the Building Regulations, with guidance set out in Technical Guidance Document B (TGD B – Fire Safety). In Northern Ireland, the equivalent guidance is Technical Booklet E.

This guide explains the fire classifications that apply to spray foam insulation, how intumescent coatings provide the required level of fire protection, and what specifiers and building owners in Ireland need to know to achieve compliance.

Why Does Spray Foam Insulation Need Fire Protection?

Spray polyurethane foam (SPF) — whether open cell or closed cell — is a plastic-based material. In its raw, uncoated state, it will burn if exposed to a direct flame. The Irish Building Regulations do not ban spray foam or any other polyurethane insulation. Instead, the installed system has to achieve the reaction-to-fire performance that the building’s fire safety design calls for.

Without an appropriate fire protection coating, spray foam insulation cannot generally be left exposed in occupied commercial buildings. In those situations the coating is not an optional extra — it is what allows the system to meet the fire safety requirements.

Fire Classifications for Spray Foam Insulation in Ireland

European Classification (I.S. EN 13501-1)

TGD B uses the European reaction-to-fire classes (Euroclasses), classified to I.S. EN 13501-1:

• Euroclass B-s2,d0 — very limited contribution to fire, limited smoke production, no flaming droplets.
• Euroclass C — limited contribution to fire. Acceptable in some lower-risk applications.
• Euroclass E — the base rating for uncoated closed-cell spray foam. Not sufficient for exposed use in most commercial settings.

Older National Classifications (BS 476 / Class 0)

• Class 1 Surface Spread of Flame (BS 476 Part 7) — the surface resists flame spread across it.
• Class 0 — a composite classification: Class 1 for surface spread of flame AND either non-combustible or a fire propagation index (I) of no more than 12. Still seen on older datasheets and specifications, and broadly comparable to Euroclass B.

For commercial buildings, the target is typically Euroclass B-s2,d0 to I.S. EN 13501-1.

How Intumescent Coatings Protect Spray Foam From Fire

An intumescent coating is a reactive fire protection material that swells when exposed to heat. At temperatures above approximately 200°C, the coating expands to many times its original thickness, forming a carbonaceous char layer that acts as a barrier between the flame and the spray foam underneath.

• Rapid activation — begins to intumesce within seconds of flame exposure
• High expansion ratio — creates a substantial insulating char
• Low smoke generation — limits smoke production during a fire event
• No flaming droplets — prevents burning material from falling and spreading fire
• Adhesion to foam — bonds directly to the spray foam surface

DC315 Intumescent Coating: The Industry Standard

DC315 is the most widely used intumescent thermal barrier coating for spray polyurethane foam insulation globally.

DC315 Technical Specifications

• Type: Water-based intumescent thermal barrier coating
• Application: Airless spray or roller
• Coverage rate: 0.5–0.75 litres per m²
• Coats required: Typically 2 coats
• Colours: White, Ice Grey, Black
• Fire rating: Euroclass B-s2,d0 when applied over closed-cell spray foam
• Elongation: Greater than 200%

When applied over Nexseal LE closed-cell spray foam, DC315 upgrades the system from Euroclass E to Euroclass B-s2,d0.

Where DC315 Is Required

• Left exposed (not covered by plasterboard)
• Installed in occupied commercial or public buildings
• Applied to soffits, car park ceilings or undercrofts
• Used in buildings where Euroclass B (or Class 0 on older specifications) is specified
• Installed in escape routes, corridors or stairwells

Application Process

1. Surface preparation — substrate cleaned and loose material removed
2. Spray foam application — foam sprayed to required thickness
3. Foam trimming — excess foam trimmed flush if required
4. First coat of DC315 — applied by airless spray
5. Drying time — minimum 4–6 hours between coats
6. Second coat of DC315 — to achieve total required dry film thickness
7. Inspection — wet film thickness checks and visual inspection

Choosing a Fire-Compliant Spray Foam Installer

Duratite coordinates commercial spray foam insulation projects through its approved installer network across Ireland and Northern Ireland. Every project where fire protection is required includes DC315 intumescent coating as standard.

Frequently Asked Questions

Book a Free Fire Protection Survey

Email us at info@duratite.ie to book a free site survey, or visit our DC315 intumescent coating page for full product details.