Intumescent Fire Varnish

  • BS476 Part 7: Class 1 surface spread of flame.

  • BS476 Part 6: Fire propagation.

  • Designated class 1, 0, & B s2 d0 in accordance with UK Building Regulations.

  • Water based clear intumescent with White Spirit based decorative overcoat in Satin or Matt finishes.

  • Brush, roller or spray application.

Intumescent fire varnish


Intended use

Fire Varnish is a varnish with the option of a clear or stained finish for Fire Protection of timber and timber derivative substrates. The special formula provides a tough, durable finish to internal and external wood. Clear or stained finishes enhance the natural beauty of the wood while fire protecting new and previously varnished surfaces. Fire Varnish Overcoat matt or satin provide protection against UV and wear.


Intumescent Fire Protection

When exposed to fire, IFV Varnish (Basecoat) expands to create an insulating barrier, protecting timber surfaces from flames, heat and oxygen and suppressing emission of deadly smoke & gasses.


Clear and Stained Varnish Finishes

IFV Varnish (Basecoat) is a clear finish which is then overcoated with FVO Varnish (Overcoat)

  • IFV Varnish (Basecoat) available in 20 sq m
  • Clear and stained FVO Varnish (Overcoat) in 20 sq m + 80 sq m packs Matt or Satin

Specification and Application

Prepare and apply -


  • 1 good or 2 standard coats IFV Varnish (Basecoat)
  • 1 coat*** FVO Varnish (Overcoat) Clear or 2 coats Woodstain. Apply 1 > 4 days after basecoat dry

** Fruitwoods or damp areas 2 FVO Varnish (Overcoat). EXTERNAL - 1 coat Astro IFV Varnish (Basecoat), 2 coats Astro FVO Varnish (Overcoat).

*** Fruitwoods, damp or high wear areas – 2nd coat Astro FVO Varnish (Overcoat).

*** EXTERNAL 2 coats Brush Grade Lacquer.


Application by painters, decorators and other professional users only. Refer to instructions on Fire Varnish Base & Overcoat containers.


Available in 20 square metre packs


We are happy to provided specifications and quotations - please use our specification form to ensure we cover all aspects of your fire protection and decorative requirements in our quote. We accept any order size.


Prior to application the contractor should contact the Technical Department (see below) to obtain a basecoat application schedule.


For help please speak to the technical team on: Tel: 01329 841 416 or Email:


Previously Varnished & Stained Surfaces or Wood Preservers

IFV Varnish (Basecoat) can be applied over firmly adhered standard clear varnish.

For existing stained varnishes, stain coatings, old fire coatings or if in doubt, contact Technical Dept.


  • If preservatives are required, use rapid drying clear non waterrepellent grades.***
  • For tanalised or other preservative treatments, contact Technical Dept.

***Allow adequate time for stain or preservative fluids to escape.


Fire Testing

Fire test standards in UKAS-accredited Fire Test laboratory


  • BS EN Class B s2 dO **
  • Class O *

Note – For 30 or 60 mins Fire Resistance, contact Technical Dept. Tel: 01329 841 416 or Email:



* Class 0 includes Class 1.


For certification and compliance with regulations the manufacturer will supply a Certificate of Supply on request.



  • Cover, countersink & fill, or use non-ferrous, galvanized, stainless or sheradised fittings
  • Ensure surfaces are dry, clean and free of all contamination
  • Varnished, sealed or non-porous wood should be abraded thoroughly with medium grade silicone carbide abrasive when dry to provide a good key.



During application & drying of the full system


  • Ensure surfaces are thoroughly dry – max 18% moisture content.
  • Maximum relative humidity RH 75%. Ensure adequate ventilation.
  • Minimum air temperature 6°C. Minimum surface temperature 3°C above dewpoint– avoid condensation.


New Fire Regulations & Tests Explained

  • The new fire standard BS EN test lasts 20 mins. with airflow replaces the old BS 476 tests which lasted 10 mins and strangely restricted airflow.
  • The new standard for flamespread and heat release Class B replaces Class 0.


The new BS EN tests also monitor -


  • Smoke & Gas “s” – s1 + s2 are none or very low & compliant, s3 = moderate smoke, s4 = heavy smoke.
  • Flaming Droplets or Airborne particulates – d0 is none, d1 = low, d2 = moderate d3 = high levels.


For more information contact us


Quality Assurance

All products are manufactured under ISO 9001.


Compatible Overcoats

When used as a primer, it can be overcoated with water-based or white spirit based paints



We have technical representatives who provide assistance in the selection and specification of the products on this site and should be consulted for exact installation and product suitability. Ensure an early engagement with ourselves, designers, main contractor and specialist installers before any installation. Other trades and/or manufacturers may need to be consulted. For in-depth information, specification and technical advice please call our Head Office on Tel: 01329 841 416 or Email:



All interested parties, designer, specifier, main contractor and specialist installers should provide access to allow the fire stopping seals to be regularly inspected and maintained, as well as records kept of such maintenance at minimum periods of 12 months, as required by the Regulatory Reform Order, and repaired if necessary. Reference should be made to ASFP TGD 17 – Code of Practice for the Installation and Inspection of Fire Stopping.



It is vital that those entrusted to design or install a fire stopping product have the necessary levels of competence to undertake the task professionally and thoroughly. The level of competency required will be commensurate with the expected complexity of the building. All designers must eliminate, reduce or control foreseeable risks that may arise during installation, construction or maintenance when preparing or modifying designs. Clients should ensure that the principal designer and principal contractor carry out their duties under CDM regulations. The ASFP foundation course in passive fire protection provides essential knowledge as part of demonstrating competency and understanding in this key fire protection specialism.


Additional Notes

This product can only be supplied once the Paint enquiry form has been completed and approved by the manufacturer: Click the following link to go to the Paint Form: Specification Form.


Health and Safety

The product does not present any known health hazards during or after installation. Normal good industrial and personal hygiene practices should be observed. For further information on health and safety please see the Safety Data Sheets (SDS) or please contact the technical team on Tel: 01329 841 416 or Email:


More information / Data sheet

For more information please click the button below to download a printable PDF file for IFV Intumescent fire varnish basecoat and FVO fire varnish overcoat Intumescent (internal and external) products.

The above information to the best of our knowledge is true and accurate and based upon current test data and is supplied for your guidance only. Customers should satisfy themselves to the suitability of the product in its intended use and no guarantee is given or implied since the conditions of actual use are beyond our control. We disclaim any liability for loss, damage or other expense arising from the use of information, data or products mentioned or referred to and reserve the right to change any details or specifications without notice.

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