Intumescent Painting Contractors
Intumescent coatings are fire-protection paints that expand when exposed to extreme heat, creating an insulating char layer that protects underlying steel from reaching critical temperatures. Anglia Decor applies intumescent systems to structural steel in factories, warehouses, high-rise buildings and industrial facilities to meet building regulations and achieve specific fire ratings: 30, 60, 90 or 120 minutes.
For tendering enquiries, please email info@angliadecor.co.uk
Intumescent Coatings for Structural Steel
Intumescent coatings function by swelling to 50–100 times their original thickness when heated above 200°C, forming a protective foam char that insulates steel from fire temperatures of 900°C+. This expansion delays temperature rise in the steel, maintaining strength and preventing structural failure during the time required for safe evacuation and emergency response. Anglia Decor specifies and applies intumescent systems to BS 476-4 and EN 13381 standards, the UK and European fire classification tests.
Fire rating depends on coating thickness, steel section size and exposure conditions. Thinner sections (I-beams, angle iron) require thicker intumescent coatings than thicker sections; a 1.5mm intumescent coat typically delivers 30-minute protection, whilst 3mm+ achieves 90–120-minute ratings. Anglia Decor’s structural steel fire protection service includes thermal modelling to determine exact thickness requirements for your steelwork. BS 476-4 testing confirms that the specified thickness delivers the claimed fire rating for your particular steel profile and coating system.
Application requires specialist preparation: surface grit blasting to SA 2.5 (ISO 8501-1), priming with zinc-rich epoxy undercoat, then two coats of intumescent topcoat. Thickness is measured at multiple points during and after application to guarantee specification compliance. Anglia Decor records all application data and test certificates for building control and insurance purposes. The coating cures fully in 2–4 weeks depending on ambient temperature, during which time the building remains operational.
Quality Assurance & Cost-Effectiveness
Quality assurance is critical: Anglia Decor applies intumescent only to certified systems with third-party fire test data for your specific steel gauge and coat thickness. Each application includes wet-film and dry-film thickness measurement, adhesion testing and photographic documentation. On completion, building control receives the full test certificates and application records proving compliance with Approved Document B (fire safety).
Cost of intumescent fire protection ranges from £15–40 per square metre of steelwork depending on section size, thickness required and system selected. This cost is typically lower than passive fire protection methods such as fire-resistant cladding or encasement, and offers no additional floor space loss. Anglia Decor's industrial painting ensures rapid application without disrupting operations: intumescent can be applied during normal working hours to most factory and warehouse steelwork, with minimal site preparation required.
Inspection and maintenance after application is straightforward. Intumescent coatings do not require recoating and are not damaged by normal industrial environment exposure (dust, mild chemical splash, temperature cycling). Any mechanical damage (gouges, scuffs) should be repaired immediately with matching intumescent topcoat to restore fire rating in that area. Anglia Decor maintains records and can undertake touch-up repairs at any point during the building's life.
Need Intumescent Painting?
BS 476 certified fire protection coatings for structural steel. Free site survey and quotation.
How It Works
Our straightforward process ensures you get the right solution with minimum hassle
Fire Rating Assessment
Determine required fire rating and specify the coating system.
Surface Preparation
Grit blast to SA 2.5 and apply zinc-rich epoxy primer.
Intumescent Application
Apply intumescent coats with continuous thickness monitoring.
Testing & Certification
DFT measurement, adhesion testing and full compliance documentation.
For tendering enquiries, please email info@angliadecor.co.uk
Why Businesses Trust Anglia Decor for Intumescent Painting
Trusted by businesses across the UK for expert, reliable service
BS 476-4 Certified
Application to UK and European fire classification standards.
30–120 Minute Ratings
Specified coating thickness for your exact steel profile and fire requirement.
Full Documentation
DFT readings, test certificates and compliance records for building control.
Thermal Modelling
Exact thickness calculations for each structural element.
Minimal Disruption
Application during normal working hours with building remaining operational.
30+ Year Service Life
No recoating required during the coating's service life.
Case Studies
Real projects delivered by Anglia Decor. See the work we've completed for businesses like yours.
Trusted by leading brands
Frequently Asked Questions
What fire ratings can intumescent coatings achieve?
Common ratings are 30, 60, 90 and 120 minutes. Your required rating depends on building classification, steel profile size and escape route times. Building control specifies the minimum rating required. Anglia Decor determines exact coating thickness needed to meet your rating based on BS 476-4 test data.
How thick must intumescent coating be applied?
Thickness ranges from 1.5mm for 30-minute protection on thick sections to 4mm+ for 120-minute protection on slender steel. Section size is critical: larger I-beams require thinner coats than angle iron or channel for the same fire rating. Anglia Decor performs thermal calculations to specify exact thickness for each element.
What is BS 476-4 and why does it matter?
BS 476-4 is the UK standard fire resistance test. It measures how long steel maintains structural integrity when coated with intumescent and exposed to standard fire temperatures. Only systems with independent BS 476-4 test data should be used. This test proves the system actually delivers its claimed fire rating.
Can intumescent coatings be applied to existing steelwork?
Yes, existing steelwork requires cleaning and grit blasting to remove paint, corrosion and contaminants, then application follows standard procedure. Blasting dust and debris must be managed to meet environmental controls. Anglia Decor can apply intumescent to both new and in-service steel with minimal downtime.
Does intumescent coating require recoating or maintenance?
Intumescent does not require recoating during its service life (30+ years). Damaged areas should be touched up with matching intumescent to restore fire rating in that zone. Anglia Decor maintains application records and performs repairs as needed throughout the building lifecycle.
How long does intumescent curing take before the building can be used?
Most intumescent systems cure within 2–4 weeks depending on temperature and ventilation. The building can be occupied and operated during curing; there is no interruption to production or use. Anglia Decor schedules application to avoid delays in building handover or operational start-up.
Ready to Start Your Intumescent Painting Project?
Our intumescent painting specialists will assess your facility and provide a tailored solution with minimal downtime.