Thermoguard Fire Varnish 30 & 60 Minute System



Thermoguard Fire Varnish 30 & 60 Minute System is a clear intumescent varnish for interior and exterior timber surfaces. Each pack contains the correct amount of basecoat (Fire Varnish Basecoat) and topcoat (Fire Varnish Overcoat (Interior) / (Exterior)) to ensure protection is achieved inline with the manufacturers recommendations to the respective area in question.

Bulk Buy

£157.00 tax excl.

£188.40   tax incl.

Product Description

Thermoguard Fire Varnish 30 & 60 Minute System is a clear intumescent varnish for interior and exterior timber surfaces. These packs have been created to help users ensure they are purchasing sufficient product for their project. Each pack contains the correct amount of basecoat (Fire Varnish Basecoat) and topcoat ( Fire Varnish Overcoat (Interior) / Fire Varnish Overcoat (Exterior)) to ensure protection is achieved inline with the manufacturers recommendations to the respective area in question.

Each component of the packs can still be purchased individually if required here: Thermoguard Fire Varnish Basecoat and here: Thermoguard Fire Varnish Overcoat (Interior) / Thermoguard Fire Varnish Overcoat (Exterior)

For fire protection to doors, see Fire Door Upgrade Kits

For BS Class 1/0 & EN Class B only see Thermoguard Fire Varnish BS Class 1/0 & EN Class B System

Pack Contents

  • 6.5m² Pack (Int/Ext. Spec.) = 1 x 20m² Fire Varnish Basecoat + 1 x 20m² Fire Varnish Overcoat (Exterior)
  • 20m² Pack (Interior Spec.) = 3 x 20m² Fire Varnish Basecoat + 1 x 20m² Fire Varnish Overcoat (Interior)
  • 20m² Pack (Exterior Spec.) = 3 x 20m² Fire Varnish Basecoat + 2 x 20m² Fire Varnish Overcoat (Exterior)


  • Apply 3 coats of Thermoguard Fire Varnish Basecoat @ 20m² per 20m² pack/per coat

Followed by either;

  • Internal Applications: 1 coat of Thermoguard Fire Varnish Overcoat (Interior) Matt or Satin
  • External, Damp or High Wear Applications: 2 coats Thermoguard Fire Varnish Overcoat (Exterior) Matt or Satin

To achieve 30 & 60mins + EN Class B s2 d0 and BS Class 1/0 minimum thicknesses apply of which approval must be sought before purchase.

A gloss finish is available in both interior and exterior versions in batch quantities for large projects.

IMPORTANT - The below information from the manufacturer must be read and referred to your relevant authority for approval BEFORE purchase and use.

We have an indicative 30min Fire Test at a UKAS Fire Test Laboratory demonstrated 10mm loss to charring on plywood & MDF.

Our Fire Varnish BS EN Class B Test indicates that softwood did not burn significantly for the 20mins test duration and our previous Class O Part 6 Fire Propagation test indicates that protected softwood did not burn within the 10 minutes test duration.

Further in-house testing indicated that when applied at three times the Class B & Class O specification Fire Varnish intumescent added a total of 20 minutes Fire Resistance.

We assess projects requiring 30 or 60mins Fire Resistance on an individual basis, referring to the TRADA Char Rate Tables and calculated residual timber to ascertain whether we could issue a Fire Certificate for the project. A written specification should be obtained from the Technical Department for your project prior to use to ensure this system will be suitable. 

In order to enable us to issue a 30 minutes Fire Certificate in the case of softwood the surface must be able to afford the loss of 8mm depth from all surfaces exposed to a fire. For 60 minutes we assess based on 30mm loss during the fire.

For oak or similar woods the loss to take into account is 5mm for 30mins and 17mm for 60mins.

In other words, the residual timber should be adequate to in the case of:

  1. Underside of a floor to support the anticipated weight load on the floor.
  2. A timber ceiling under-drawing a floor and joists can be treated as sacrificial but should have protected the area above to 30mins
  3. A timber wall should still be able to support itself without the fire passing through to the area the other side.

Timber must be clean and thoroughly dry prior to application (maximum 18% moisture content).

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

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 Eddie Attwood on 12/01/2019

Can the product ref: FV3060 be applied over an existing varnished door (i.e. not need to be stripped) and do extra coats increase the fire rating minutes?


No, Thermoguard Fire Varnish 30 & 60 Minute System cannot be applied over existing varnish on a door but Envirograf Door Upgrade Varnish System can.

questions Dave Molyneux  on 13/12/2018

Can this product (external) be over painted with a shed/fence type wood stain at a later date and still retain it's fire protection? Many thanks Dave.


No. Something like Zeroflame Fire Retardant Treatment can be overcoated with waterborne stains or varnishes as long as they are compatible, non-flammable and will dry. We always recommend to try a small sample area first to ensure the stain does not react with the Zeroflame Fire Retardant Treatment and will dry out. However this only achieves Euroclass B (BS Class 0) Fire Propagation and Spread of Flame fire protection and has to be applied to bare (not man-made) timber only.

questions David Molyneux  on 26/11/2018

Can this product be used over timber that has been coated with a water based wood stain. Many thanks Dave.


Please see below the manufacturers recommendations (at the time of writing this response) when using the Thermoguard Fire Retardant Varnish system over existing wood stains.


Penetrating Wood Dyes / Spirit Stains based on low flash solvents (eg Xylene, Toluene, Alcohols). Benefits are – Quick drying, do not seal wood.


Penetrating Wood Dyes based on Water (not water repellent). Precaution - wait for all water to come out of wood before overcoating.

Usable with Caution;

Nitrostain, White Spirit Penetrating stains (single coat of matt only). Precautions - Allow to dry thoroughly (up to 2 weeks for white spirit) Degrease with warm detergent solution necessary with some sanding required if a solid film has been formed.

Not Recommended;

Stains containing Water Repellents, Waxes, Oils, Coal Tar Distillates / by-products, satin or gloss woodstains or other stains which seal the wood or stains that deposit a weak film of underbound pigment. “Home recipes” combining stains and lacquers. N.B. Consult the Technical Department if these have been applied already or if in doubt.

Compatible Pre-Existing Coatings;

Long oil Varnish, Yacht Varnish or Polyurethane Varnish - Require thorough sanding to give a “key”, Non water-repellent organic solvent preservative (provided thoroughly dry). For others please consult the Technical Department.

Incompatible Surfaces;

Photographic faced hardboard, CCA “Tanalised” or water-repellent grade preservative treated timber. Emulsion paint, old “1st generation” type clear fire coatings*.

*If these may be present, contact Technical Department for specific advice, tests etc.


Paint should be overcoated with a suitable Thermoguard Timbercoat system in chosen colour. Paints cannot be successfully coated with a clear fire varnish because adequate abrasion of hard or smooth paint damages the colour, while softer emulsions & acrylics cause the varnish to craze or shrivel.

questions Neil Kaiper-Holmes on 22/09/2018

Can this be used on external decking?


No, Zeroflame Fire Retardant TreatmentThermoguard Thermoproof Exterior Fluid and Hydron Nu-Flame Clear Impregnation can all be used on exterior, bare, porous timber decking but these will only achieve BS Class 1/0 and/or Euroclass B and not 30/60min protection.

questions Rebecca Hibbert on 20/08/2018

I have a single storey timber built annex that needs fire retardent applied externally to one side only. The area that needs protection is 70 foot long. I am thinking of purchasing the Thermoguard Fire Varnish 30 & 60 Minute System. Can you please advise how much I would need. Many thanks.


Could you advise what level of fire protection you require, the height of the area, the thickness of the wood to coat and whether it is bare or previously coated with something?

questions Constantine Petropoulos on 24/04/2018

Does this product have a UL rating and does it meet ASTM standards?


Thermoguard Fire Varnish has NOT been submitted to either UL or ASTM for approval/testing.

questions Mark Lewis on 11/03/2018

How do you issue a certificate do you come on site


After use, certification can be applied for HERE.


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