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Intumescent Painting — Fire-Resistant Coatings for Structural Steel

Fire-Resistant Coatings Applied to Perfectly Prepared Steel

Commercial Shot Blasting offers a complete intumescent painting service for structural steel, fire escapes, and industrial metalwork. We shot blast to Sa 2.5, apply certified intumescent coatings, and provide full DFT documentation for fire resistance ratings from R30 to R120.

Our Process

1. Site Survey & Specification

We assess the steel, confirm the required fire resistance rating (R30, R60, R90, R120), and agree the coating system and DFT specification.

2. Surface Preparation by Shot Blasting

All steel is shot blasted to Sa 2.5 or Sa 3 to remove mill scale, rust, and old coatings and create the correct surface profile for maximum adhesion.

3. Primer Application

An approved zinc-rich or epoxy primer is applied immediately after blasting to prevent flash rusting and provide the correct base for the intumescent topcoat.

4. Intumescent Coating Application

The intumescent basecoat is applied in controlled passes to achieve the specified DFT for the required fire resistance rating. DFT is measured and logged.

5. Sealer / Topcoat

A protective sealer or decorative topcoat is applied over the intumescent layer for weather resistance and the required finish colour.

6. Inspection & Documentation

A full DFT survey is carried out and a coating report issued, ready for building control or fire engineer sign-off.

Applications

  • Structural steel frames
  • Mezzanine floors and steel platforms
  • Fire escapes and stair towers
  • Internal staircases and handrails
  • Steel portal frames
  • New build and refurbishment projects

Frequently Asked Questions

What is intumescent paint and how does it work?

Intumescent paint expands under heat to create an insulating char layer around steel, maintaining structural integrity for the specified fire resistance period — typically R30, R60, R90, or R120.

Why does steel need shot blasting before intumescent painting?

Intumescent coatings require strong adhesion to perform correctly. Shot blasting to Sa 2.5 removes all contaminants and creates the surface profile needed for maximum mechanical adhesion.

What fire resistance ratings can you achieve?

We can achieve fire resistance ratings from R30 to R120 depending on the steel section factor, the coating system specified, and the required DFT.

Do you provide a coating thickness report?

Yes. We measure dry film thickness on every coated member and provide a full coating report with product data sheets, batch numbers, and thickness readings for building control.

Where We Offer Intumescent Painting — Fire-Resistant Coatings for Structural Steel

Our mobile units deliver intumescent painting — fire-resistant coatings for structural steel services across 35 counties in England and Wales. Select a county to see all the towns and areas we cover.

  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Bedfordshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Berkshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Buckinghamshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Cambridgeshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Cheshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Cumbria
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Derbyshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in County Durham
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in East Wales
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Essex
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Gloucestershire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Greater Manchester
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Hampshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Herefordshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Hertfordshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Lancashire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Leicestershire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Lincolnshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Norfolk
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in North Devon
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in North Yorkshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Northamptonshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Northumberland
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Nottinghamshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Shropshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Somerset
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in South Yorkshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Staffordshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Suffolk
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Tyne & Wear
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Warwickshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in West Midlands
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in West Yorkshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Wiltshire
  • Intumescent Painting — Fire-Resistant Coatings for Structural Steel in Worcestershire

Related Guides

  • Why Shot Blasting is Essential Before Intumescent Painting
  • The Complete Guide to Shot Blasting Structural Steel
  • How to Specify Surface Preparation for Structural Steel

Get a Free Quote for Intumescent Painting — Fire-Resistant Coatings for Structural Steel

Contact Commercial Shot Blasting for professional intumescent painting — fire-resistant coatings for structural steel services across the UK.

Phone: 07970 566409

Email: [email protected]