HolzProf Fire Retardant 10L - Liquid flame retardant for natural cork

This solution soaks into cork and slows down the burning process while also minimising fire spread. As a result, flames develop more gradually, giving you extra time to respond in an emergency.

HolzProf can be applied to wood and other materials made of cellulose – including cork. Being a water-based solution, it doesn’t affect the cork’s natural appearance or feel.

Keep in mind: The product only works if the surface absorbs it. It will not be effective on cork that has already been painted, varnished, or sealed with any coating that blocks absorption.

Use protective gloves and eye protection, and make sure there is sufficient airflow in the room. If you are spraying, wear a mask with a P3 filter. These precautions ensure the job is done safely and comfortably. Always stick to the manufacturer’s guidance.

The cork surface should be dry, dust-free, clean, and without grease, stains, or leftover adhesives.

Note: To let the fire retardant sink in, the cork cannot be painted, varnished, or covered with any finish that prevents absorption. Only untreated cork allows the product to work properly.

• You can apply it using a brush, roller, by dipping the cork, or – with the right tools – by vacuum-pressure application. Whichever method you choose, ensure the cork is treated on all sides.
• The cork’s moisture level should ideally be around 16%, with a maximum of 18%. Do not apply the product to frozen or icy surfaces.
• HolzProf should be applied in three layers, with breaks of 40–60 minutes between coats. Total usage should be at least 300 g/m² (270 ml/m²), and for denser woods like Canadian WRC cedar, no less than 360 ml/m². To protect effectively, the liquid must reach 1.5–3 mm into the cork. Apply only at +10–30°C (minimum +5°C) with humidity lower than 75%.
• Complete fire resistance is achieved after 7 days (under ideal conditions – about 20°C and humidity under 75%). While drying, keep cork away from rain and direct sun.

Keep the product in its original, well-sealed container, in a cool, dry, and ventilated area. Storage temperature should remain between +5°C and +25°C. Avoid exposure to frost.

The product stays effective for 24 months from the manufacturing date.