Intumescent paint and varnish is a type of treatment for various surfaces, including wood, which slows down the effects of fire

fireproof paint

One of the great battles in the world of construction and architecture is to raise buildings and constructions with increasing fire resistance. In this combat, one of the resources used are the treatments or products that, applied to the structure, give it a greater capacity to resist fire. In the present case, intumescent paints that can be applied mainly to metals and, in some cases, to wood, and intumescent varnishes that are applied to wood.

The action of intumescent paint and varnish It consists of the use of chemical products, usually resins, which, when in contact with the heat produced by fire or flame, are transformed into a foam that covers the structure to protect it thanks to its low thermal conductivity, that is, it does not leave the heat or flame. The delay can be up to 1 hour. With that they can two effects:

  • Stop the destructive action of fire.
  • Avoid spreading the fire.

With intumescent varnishes and paints the result is not perpetual, that is, serve as a temporary brake to the action of the fire, but at some point, if the situation persists long enough, around 25 in a standard application, the fire will overcome the foam or layer generated by the paint in question and act on its own.

These flame retardant treatments for wood and other materials can be found for use with solvents and water, which significantly reduces odors after application. For this, it is not necessary to use specific material or personnel with specific training in addition to a qualified painter.

Recommendations for the use of intumescent products

  • Internal application, unless it is specifically for external use, as the weather can deteriorate the applied layer and, therefore, drastically reduce its effectiveness.
  • Apply on clean and prepared surfaces. It is more than convenient that there are no layers of other poorly adhered products. There are and recommended the use of fire retardant primers that will improve the adherence of the product.
  • Especially in the case of wood and intumescent varnishes its use is not recommended in woods that will suffer wear, for example on platforms or stairs. It is mainly used for ceilings, beams, coverings or panels.
  • Trust only brands that provide evidence or information about testing your products.
  • Follow the manufacturer’s recommendations for the number of coats, drying time, limitation for diluting intumescent paint, etc.

Intumescent varnishes in wooden construction

In the event of a fire, wooden structures are consumed at a relatively constant speed. The action of fire reduces the thickness of the beams until the structure collapses.

In the case of wood, these times can be calculated, and as a curiosity is the fact that it is much longer than usual.

Intumescent varnishes will increase this period to collapse considerably, even up to an hour. This gives enough time to vacate the building or wooden house and even for firefighters or other professionals to put an end to the fire.