Thermoguard Fire Varnish Basecoat



Thermoguard Fire Varnish Basecoat is a clear intumescent varnish that is the first coat of a 2 coat system (3 coat externally) for the decorative Fire Protection of timber and timber derived substrates to Class 1, Class 0, EN Class B s2 d0. See Thermoguard Fire Varnish 30 & 60 Minute System for 30 & 60 minutes Fire Resistance.

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£103.00 tax excl.

£123.60   tax incl.

Product Description

Clear Fire Protection Basecoat for Fire Varnish System for Wood

Thermoguard Fire Varnish is a clear varnish system for the Fire Protection of timber and timber derived substrates to BS Class 1 and Class 0 Surface Spread of Flame as well as BS EN Class B s2 d0 (for 30 or 60 minutes Fire Resistance see Thermoguard Fire Varnish 30 & 60 Minute System). The special formula provides a tough, durable finish to internal and external wood. The clear finish enhances the natural beauty of the wood while providing protection against UV and wear as well as fire protecting new and previously varnished surfaces.

The Thermoguard Fire Varnish System is made up of Thermoguard Fire Varnish Basecoat (a two component product consisting of a base and activator mixed together before use - see image above) which is a clear, intumescent varnish to be finished with Thermoguard Fire Varnish Overcoat (Interior) or Thermoguard Fire Varnish Overcoat (Exterior) available in a clear matt or satin finish (a gloss finish is available in both interior and exterior versions in batch quantities for large projects). The Thermoguard Fire Varnish Overcoats provide protection against UV, weathering (Exterior Grade) and wear whilst Thermoguard Fire Varnish Basecoat provides the Fire Protection.

Intumescent Fire Protection

When exposed to fire, the Thermoguard Fire Varnish System expands to create an insulating barrier, protecting timber surfaces from flames, heat and oxygen and suppressing emission of deadly smoke & gasses.

Specification and Application

Prepare and apply – (INTERIOR)

  • 1 coat of Thermoguard Fire Varnish Basecoat
  • 1 coat of Thermoguard Fire Varnish Overcoat (Interior) Matt or Satin


  • 1 coat of Thermoguard Fire Varnish Basecoat
  • 2 coats of Thermoguard Fire Varnish Overcoat (Exterior) Matt or Satin

Available Pack Sizes

  • Thermoguard Fire Varnish Basecoat is available in 20m² packs
  • Thermoguard Fire Varnish Overcoat (Interior) is available in 20m² and 80m² packs
  • Thermoguard Fire Varnish Overcoat (Exterior) is available in 20m² and 40m² packs

Applicators should also refer to instructions on product containers.

Previously Varnished and Stained Surfaces or Wood Preservers

The Thermoguard Fire Varnish System can be applied over firmly adhered standard clear varnish. For existing stained varnishes, stain coatings, old fire coatings or if in doubt, contact our Technical Department on 0113 2455450.

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

**Allow adequate time for stain or preservative fluids to escape before applying the Thermoguard Fire Varnish System.

Fire Test Standards and Certification

  • BS EN Class B s2 d0
  • Class 1 and Class 0

Note - For 30 or 60 mins Fire Resistance see Thermoguard Fire Varnish 30 & 60 Minute System.

For fire protection to doors, see Fire Door Upgrade Kits

We will issue a Certificate of Supply upon request for each correctly specified project for Insurance, Fire and Building Control Authority and Client Records against proof of purchase.


  • 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 and 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 restricted airflow.
  • The new standard for flamespread and heat release Class B replaces Class O.

The new BS EN tests also monitor -

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

IMPORTANT FIRE PRODUCTS NOTICE: The information displayed on this website should be used as a guide ONLY and our Technical Department should be contacted to obtain a tailored specification and any advice necessary before you place an order for fire protection products. Fire protection products are non-returnable except in accordance with Condition 8 of the Terms and ConditionsWe will not be held liable for any resulting damage to property, human life or monetary costs incurred due to the incorrect specification you have prepared or use of fire protection products caused by your negligence, including your failure to have contacted us to obtain the relevant advice/specification.

It is your responsibility to read the Product Data Sheets (available below) before you place an order and prior to application of the product. The content of this website is our best recommendation and is not advice. Coverage rates quoted are approximate, you agree that coverage depends on the condition of the substrate, surface absorption, texture and application method. We ALWAYS recommend a trial area is coated to ensure the product meets your requirements before use.

Technical Data

Typical Coverage (per coat)Supplied in pre-measured packs to apply 1 coat to 20m²
Touch Dry18 Hours
ApplicationBrush, Roller, Spray
The figures stated above are approximate. Please ensure you refer to all datasheets for full application information.


Customer agrees that before placing an Order, Customer has read and understood the most up to date Product Data Sheet for the Product. Where we have access to the Product Data Sheet from the manufacturer, we will either provide a copy on request, or include a link to the Product Data Sheet available on the manufacturer’s website. Customer further agrees that we have no liability for any errors or omissions contained within the Product Data Sheets. For more information, please see our Terms & Conditions of Sale.


questions james watt on 15/10/2018

Can this be put over painted wood ?


No, but if you contact our Technical Team on 0113 2455450 (option 2) or [email protected] with your full requirements we may be able to provide a solution for you.

questions Robert Harris on 10/11/2016
Question: Hi
Does the clear varnish product turn a mdf veneered board from no fire
Protection to 30min protection?

Is there a choice of satin or gloss finish too?
Is the varnish fully clear or is lightly tinted?

Thermoguard Fire Varnish Basecoat provides BS Class 1, Class 0, EN Class B s2 d0 protection to timber and timber derived substrates. It is a clear varnish (not lightly tinted) available in matt, satin or gloss finishes.

30min protection can be achieved using the Thermoguard Fire Varnish System but approval must first be sought from the governing authority on the project for information provided by our Technical Department. To receive a 30min specification and supporting documentation for submission, please contact our Technical Team on 0113 2455450 or [email protected]

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