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.
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)
- 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.
Prepare and apply – (EXTERIOR, DAMP, HIGH WEAR AREAS or FRUITWOODS)
- 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.