Fire Protection for Woods

In Public Access Buildings, bringing wooden elements up to code is a strict safety obligation. To obtain your fire rating (M1 or Euroclass B-s1, d0), two technologies are available to you: saturation impregnation (Eurobois) or film-forming protection (Varnish). Making the right choice depends primarily on the nature of your substrate (Solid or Panel) and the desired aesthetic finish.

Here are the decisive criteria to select the right product and validate your safety commission inspection.

Eurobois: Invisible French M1 fire rating Impregnation for Raw Solid Woods

This is our simplest solution to implement. Eurobois is a liquid fire retardant that acts by saturation: it penetrates the heart of the wood fibers.

For which substrates?
Ideal for all solid woods (softwoods or hardwoods), beams, paneling, structural timber, and raw wood pallets (especially spruce). The wood must be able to “drink” the product.

Major Advantages:

• Invisible: Does not alter the wood’s appearance, leaves no trace (no whitening, no shine).
• Express Application: Sprays easily (sprayer), without complex layer thickness management.
• Validated Standard: M1 Rating (French Standard).

Technical Constraint: This product is non-film-forming. Therefore, it cannot be applied to water-repellent panels or heavily glued woods that refuse impregnation.

> Order Eurobois fire retardant. French M1 fire rating 

Intumescent Varnish: Euroclass B-s1, d0 Protection for Panels (OSB, MDF) and Satin Finish

The intumescent varnish works differently: it creates a protective film on the surface (film-forming). Under the effect of heat, this film swells to form an insulating foam (carbonaceous char) that protects the material.

For which substrates?
Indispensable for reconstituted or dense woods (>300kg/m³) that absorb liquids poorly: OSB, MDF, Chipboard, Plywood. It is also the aesthetic choice if you want a “satin varnish” finish.

The Two-Step System:

1. The Intumescent Varnish (Mandatory): This is the active layer that ensures fire protection and Euroclass B-s1, d0 compliance (European Standard). Note: it may slightly whiten the wood and cracks upon contact with water.
2. The Finishing Varnish (Optional but Recommended): It protects the intumescent varnish from friction and humidity. Indispensable for tactile areas (handrails, counters, low walls).

> Order Intumescent Varnish B-s1, d0

The Special Case of Renovation on Already Painted Wood

Many clients wish to treat wood that is already painted or varnished without sanding. Here is the technical reality versus the regulatory reality:

• With Eurobois (Spray): Impossible. Painted wood is “blocked”; the product will run off without penetrating.
• With Intumescent Varnish: This product is compatible with already painted or varnished woods. Adhesion and protection are ensured.
  Attention to the Administrative Framework: The reference Official Test Report (PV) mentions “raw wood”. The procedure is therefore as follows: before ordering, present our Test Report to your safety commission or inspection office. Once they have validated the use of the PV on your painted support, you can apply the varnish directly without sanding.

Vigilance Points for the Validity of Your Certificate

To guarantee the safety of your establishment and the validity of your M1 or Euroclass certificate, keep these two technical rules in mind:

• Prohibition on covering Eurobois: The impregnation fire retardant must remain in direct contact with the air to carbonize in case of fire. It is strictly forbidden to paint or varnish it after application. This would nullify its effectiveness and the validity of the PV.
• Respect for coverage rates: Whether by saturation (Eurobois) or by film thickness (Varnish), respecting the quantity of product per m² indicated on the technical sheet is imperative to obtain certification.