• On sale!
  • Reduced price

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


Thermoguard Fire Varnish BS Class 1/0 & EN Class B s2 d0 System is a clear fire retardant varnish for interior and exterior timber surfaces.

Please Note : Woodstains are only available on the following shipping options:

  • Express: 1-3 Working Days Delivery (Thermoguard DS)
  • Economy: 7-10 Working Days Nationwide Delivery

See further below for representations of available translucent wood stains - these are shown in the colour picker as solid colours.

Product customisation

Don't forget to save your customization to be able to add to cart
  • 250 char. max
Colour Group
£162.72(ex. VAT) Save 10%
£195.26 (inc. VAT)
Please choose your colour
In Stock and Available for Delivery (See Delivery Options Below)


Thermoguard Fire Varnish BS Class 1/0 & EN Class B s2 d0 System

Thermoguard Fire Varnish BS Class 1/0 & EN Class B System is a clear fire retardant 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) to ensure protection is achieved inline with the manufacturers recommendations to the respective area in question.

The Thermoguard Fire Varnish system is specially formulated to provide a tough, durable finish to internal and external wood. Clear or stained finishes enhance the natural beauty of the wood while fire protecting surfaces. The Fire Varnish Overcoat in Matt or Satin finishes provide protection against UV and wear.

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.

Transparent Wood Stains (interior packs only)

Representations shown below; represented as solid colours in the colour picker further above.

Recommended Uses

  • Beams/Joists
  • Walls
  • Ceilings

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

Pack Contents

  • 20m² Pack (Interior Spec.) = 1 x 20m² Fire Varnish Basecoat + 1 x 20m² Fire Varnish Overcoat (Interior)
  • 20m² Pack (Exterior Spec.) = 1 x 20m² Fire Varnish Basecoat + 1 x 20m² Fire Varnish Overcoat (Exterior)

Specification and Application

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)

Prepare and apply – (INTERIOR)

  • 1 coat of Thermoguard Fire Varnish Basecoat
  • 1>4 days after Basecoat is dry, apply 1 coat of Thermoguard Fire Varnish Overcoat (Interior) Matt or Satin Clear or 2 coats of Thermoguard Fire Varnish Overcoat (Interior) Matt or Satin Woodstain Colour.


  • 1 coat of Thermoguard Fire Varnish Basecoat
  • 1>4 days after Basecoat is dry, apply 2 coats of Thermoguard Fire Varnish Overcoat (Exterior) Matt or Satin Clear.

Please note: Timber must be clean and thoroughly dry prior to application (maximum 18% moisture content). Any gaps should be sealed with Thermoguard Intumescent Mastic. Fire should be prevented from accessing unprotected wood surfaces and for external applications it is recommended wood has been sealed on the reverse face to stop water ingress.

NOT suitable for the topside of floor surfaces that will be trafficked/walked on.

A gloss finish is available in batch quantities for large projects, contact us for details.

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

Thermoguard 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. After successful application of a complete system a certificate can be applied for HERE


  • 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.

Application to OSB/Sterling Board

This is a board made of chips of wood glued together to form a hard non-decorative board. If it needs fire coating, Thermoguard Fire Varnish or Thermoguard Timbercoat BS Class 1/0 & EN Class B System can be applied to it. However we first recommend a test is carried out by applying a small amount of the proposed coating to the board to check for "cessing" / "cissing" (where coating gathers together in lumps and may leaving bare patches between). If this occurs the board should be degreased/cleaned and allowed to dry before testing again - if this still does not provide a satisfactory application please contact our Technical Team for further advice on 0113 2455450 (option 2) or send a message to [email protected].

Important Application Notes

The Thermoguard Fire Varnish System should only be applied to dry wood, with dry conditions during application and drying of basecoat and overcoat.

Thermoguard Fire Varnish Basecoat is a water-based 2 pack coating.

Thermoguard Fire Varnish Overcoat (Interior or Exterior grade) should not be applied unless the basecoat is dry. Drying time of the basecoat in good conditions is overnight. Once the basecoat has dried in good conditions the basecoat remains ideal to overcoat for a further 4 days. Thereafter, the basecoat becomes gradually harder, until it reaches a point where the overcoat may not obtain a good bond.

Thermoguard therefore recommend overcoating when basecoat is dry, within the following 4 days in good conditions.

Delamination of overcoat caused by application to near-full cured basecoat has NEVER occurred when the overcoat was applied within 7 days. The longer the delay beyond '4 days after basecoat has dried' (so typically 5 days after application), the greater the risk of overcoat delaminating.

If overcoating is delayed notably beyond 7 days after the basecoat was dry, it is advised;

  • Basecoat is abraded to obtain a key with 120 grit abrasive
  • Apply a light coat of basecoat to replaced material removed during abrasion
  • Apply overcoat within the ideal window or as near to it as possible


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 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.

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 Conditions and should be applied only by an individual with the necessary expertise and experience. We 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.

Product Details

Data sheet

Brush, Roller, Spray
Best Seller
Best Seller
Fastest Delivery
Next Working Day

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 tim prior on 2022-07-28 08:44:51

is there a use by date on this product? i bought a batch in may, and its remained un opened until now. will it still be ok to use?

Answer from Rawlins’ Technical Team: 

Thank you for the enquiry, please send the proof of purchase along with the batch numbers from the tins to [email protected] and we can check with the manufacturer for you.

questions Neil Osborne on 2022-05-17 15:59:01

Hi, we bought thermoguard from Rawlins to provide a O grade finish to a log cabin in 2015. We've since recoated twice but were wondering if there's a recommended reapplication time period? And also whether we need to apply for a new certificate each time? I can provide previous info and fire certificate, receipt etc if required. Thanks Neil

Answer from Rawlins’ Technical Team: 

There is not a set reapplication period, but the topcoat should be reapplied anywhere between every 4 to 7 years.

This system needs to be maintained, so if it wears or is damaged it should be reapplied.

The original certification will still stand and does not need to be applied for again.

questions will on 2020-11-10 17:33:02

Is this suitable for use on raw birch ply sheets in a kitchen area?

Answer from Rawlins’ Technical Team: 

Assuming you are looking to achieve a Class 0 level of fire protection, the bare wood is not used as a surface to place items on, it is clean, dry and sound yes is could be used on Birch plywood. For areas exposed to steam we would recommend the Exterior pack with the extra coat of Fire Varnish Overcoat.

questions Sean on 2019-11-05 21:41:26

Is it a requirement that a qualified tradesman apply this or can if be applied by myself? Thanks

Answer from Rawlins’ Technical Team: 

Application of this system should be by painters, decorators and other professional users only.

questions Ryan McCreadie on 2019-08-30 10:23:45

hi, what is the lifespan of your products once applied (approx.). i'm looking at a coating to timber that achieves a class 0 finish. thanks ryan

Answer from Rawlins’ Technical Team: 

We would need to know some more details of the application, i.e. internal or external, expected cleaning regime, chemicals, etc. Please contact our Technical Team on 0113 2455450 (option 2) or [email protected] to discuss.

questions James on 2019-05-23 22:27:28

Can this be applied over Polyx oil or Wood Wax Finish?

Answer from Rawlins’ Technical Team: 

No, neither can be used, see notes below on existing coatings before the use of Thermoguard Fire Varnish BS Class 1/0 & EN Class B System;

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

Acceptable: 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 / bye-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. Note: Consult the Technical Team 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 Team.

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

Paints: Paint should be overcoated with Thermoguard Timbercoat BS Class 1/0 & EN Class B System in your chosen BS or RAL 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 varnish to craze or shrivel.

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

questions Frank Caldwell on 2017-05-16 16:15:17

What is the drying times for this product?

Answer from Rawlins’ Technical Team: 


Leave a minimum of 36 hours in good drying conditions to dry HARD. Within 96 hours of of Thermoguard Fire Varnish Basecoat becoming and remaining dry, apply Thermoguard Fire Varnish Interior/Exterior Overcoat by brush, roller or spray.


  • Interior: Touch Dry: 8 hours / Overcoat: 12 hours
  • Exterior: Allow to cure for at least 2 hours, denib then apply second coat within 36 hours.

Question about the product

* Required fields


Thermoguard Fire Varnish BS Class 1/0 & EN Class B System is only available with the shipping and delivery timescales listed below - please do not contact our Customer Support Team with enquiries about alternative or earlier shipping and delivery times.

Saturdays and Sundays, as well as Bank Holidays, are not classed as working days.

Orders placed after the cut-off for this product will not be processed for earliest dispatch until 9am the next working day.

All delivery costs below are excluding VAT

You might also like

Thermoguard Fire Varnish Basecoat

Thermoguard Fire Varnish Basecoat is a clear intumescent varnish that is the first coat of a 2 coat system (3 coats externally) for the decorative Fire Protection of timber and timber derived substrates to BS Class 1, Class 0 and EN Class B s2 d0. See Thermoguard Fire Varnish Overcoat (Interior), Thermoguard Fire Varnish Overcoat (Exterior) or...

Price £120.00 (ex. VAT)
In Stock and Available for Delivery

General Painting Application Kit

General Painting Application Kit from Rawlins Paints provides the basics for any painting project. Whether it is a one off job, or you just want to make sure the right application tools get to site. Provides an economical way of making sure you will have what you need Ideal for interior and exterior paint projects Click to jump down to...

Price £8.02 (ex. VAT)
In Stock and Available for Delivery

Thermoguard Fire Varnish 30 & 60 Minute System

Thermoguard Fire Varnish 30 and 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 (Thermoguard Fire Varnish Overcoat (Interior) or Thermoguard Fire Varnish Overcoat (Exterior)) to ensure protection is achieved inline...

Price £162.72 (ex. VAT) Regular price £180.80
In Stock and Available for Delivery

Thermoguard Fire Varnish Overcoat (Exterior)

Thermoguard Fire Varnish Overcoat (Exterior) is a decorative lacquer for use over Thermoguard Fire Varnish Basecoat for EXTERIOR surfaces. Restricted to professional users. Not for sale to, or use by the general public. Each 20m2 pack of Thermoguard Fire Varnish Exterior Overcoat is sufficient to apply the required 2 coats to 20m2 of...

Price £120.00 (ex. VAT)
In Stock and Available for Delivery