How to fireproof wood?

This blog post will answer the question, “How to fireproof wood” and cover topics like methods of fireproofing a wood and frequently asked questions related to the topic.

How to fireproof wood?

Here’s how you can fireproof wood:

  • Fill a bucket halfway with water.
  • Add 1/2 cup zinc chloride, 3 tbsp. boric acid, 1/4 cup ferric chloride, and 3 tbsp. ammonium phosphate to the water. These compounds are available in agricultural & gardening supply shops, as well as chemical supply companies.
  • Combine the ingredients together completely. To protect your wood against fire, paint or spray 2 to 3 applications of the mixture on it.

What Exactly Is Fire-Resistant Wood?

Wood that has been coated with fire-retardant chemicals produces a product that prevents ignition and reduces the spread of fire substantially. 

Several fire-retardant wood items are also examined for corrosivity, paints & stain compatibility, and if the fire retardant compounds leach from the wood.

Wood that has been sprayed with a coating or other exterior fire resistant is not regarded as fire-retardant; it must be thoroughly integrated into the wood to be termed fire-retardant. 

Above all, fire-retardant timber is a crucial safety feature that attracts customers, lowers the cost of insurance, & saves lives.

Is It Possible for Fire-Retardant Wood to Get Wet?

This is a crucial issue for any building project, and the answer is more complicated than a simple yes or no. Some fire-retardant wood, but not all, maybe wet.

The primary distinction is whether the timber has been treated to reduce dampness, both in terms of the wood’s own swelling and warping, and if the fire-retardant chemicals may seep out of the wood if exposed to moisture. 

Water leaching produces a variety of issues, the most serious of which is the loss of flame-retardant qualities and contamination of neighboring soil and water systems.

Methods of fireproofing wood

Two methods of fireproofing wood are given below:

1st Method: Make Your Own Heat Resistant Wood Spray

  • Fill a bucket with about two quarts of water from the tap.
  • Combine 1/4 cup ferric chloride, ½ cup zinc chloride, and 4 tbsp ammonium phosphate & boric acid in a mixing bowl. Using a completely dry wooden stick, thoroughly mix all of these substances. Wear gloves if you’re going to contact this solution with your bare hands.
  • Pour the mixture into a spray bottle after thoroughly mixing the components. If you don’t have a spray bottle, you may just paint it on the wood.
  • Finally, spritz your wood with at least two to three applications of this heat-resistant liquid. When using a paintbrush, the same rule applies. Allow it to cure, and you’ll have a fire-safe and heat-resistant wood!
Materials Needed
Zinc chloride
Ferric chloride
Boric acid
Ammonium phosphate
Spraying bottle
Mask and Gloves

All of these substances are available at local agricultural or gardening supply shops or you can buy them online.

While neither this nor the following procedure will make the wood fully fireproof, they will reduce the chances of it igniting. After that, here’s another quick and easy way to make your timber flame resistant. 

If you don’t have access to any of the chemical substances needed for the procedure above, try the approach below. This strategy is both efficient and effective. So, without further ado, let’s get started!

Method 2: Make-Your-Own-Heat-Resistant-Spray

  • The first step is to make a saturated solution. To do so, fill the saucepan halfway with water & bring it to a boil.
  • Remove the pan from the heat and stir roughly 2 1/2 tablespoons of Borax into the boiling water. Stir the mixture until all of the Borax has dissolved.
  • Allow for the solution to cool to room temperature. You’ll see that part of the Borax has sunk to the bottom after a few mins. This is quite normal, and the clear fluid at the top is your heat-resistant solution.
  • Fill your spray bottle & storage jar with this clear solution, then go to the following step for instructions on how to use it.
  • Take the wood that has to be protected and soak it well. Spray the solution liberally now. Leave it to dry before applying a couple more coats. The goal is to fully absorb the solvent into the wood.
  • Allow the subject to fully dry before protecting it from moisture. The solution will be washed away if it comes into touch with water.
Materials Needed
Cup for measuring
Spoon for measuring
An extra saucepan

So there you have it: the basic strategies for making your wood flame-resistant on your own. These approaches, however, are not permanent. 

As previously stated, any interaction with moisture will cause this solution to degrade over time. So, if you want to keep wood constantly warm and fireproof, you’ll need to hire an expert.

Using a fire-resistant coating is one of the most effective methods. This technique may be used on any wooden surface, including walls, furniture, floors, and ceilings. 

It’s generally a transparent coating to avoid interfering with the aesthetics and allowing the wood’s natural character to come through. However, since this kind of therapy requires the involvement of a specialist, it is often costly.

What Are Fire-Retardant Paints or Coatings?

Special kinds of materials, such as fire-retardant coatings and paints, are critical for preserving wood from heat & fire. These coatings are often used to preserve wood-finished houses in the woodworking industry. They are readily available at any home depot.

One thing to bear in mind when buying fire-resistant paint is that it must fulfill the BS 476 safety standard when applied in residential and commercial structures.

How Does Fire-Resistant Paint Work?

Fire-retardant paints operate by establishing a protective coating on wood that shields it from flames. By using the energy generated during foaming, the paint swells up and produces a foam-like layer. 

When this occurs, the underlying hardwood surface is insulated, which preserves it. Not only that, but when the wood is coated with flame retardant compounds, it provides other advantages such as reduced smoke output, shorter igniting times, and fewer blazing droplets. 

Furthermore, fire resistant treated wood provides extra time for people to flee during a fire.

Which kind of natural wood is the least flammable?

The bulk of hardwoods is the least flammable when it comes to natural timbers. Mahogany, oak, teak, & maple are among them. 

The reason for this is because hardwood has a higher density than other kinds of wood. As a result, when exposed to heat and flame, they will ignite slowly.

What Is the Purpose of Fire-Retardant Wood?

Check local code requirements before utilizing fire-retardant timber for any of these projects or building components. 

Here are some examples of indoor and outdoor projects that might benefit from the usage of fire-resistant wood materials.

  • Interior
  • Exterior
  • Residential Structures
  • Projects Outside the Home

I will now elaborate on the guidance given above.


In residential structures, especially crowded developments like townhouses and row houses, fire-retardant wood is an excellent option for hallways and ceiling supports. 

In the event of a fire, adding fire-resistant wood to high-traffic areas may help safeguard the structure’s integrity, providing families more time to flee & firefighters a greater chance of putting the fire out.

Theater decor, exhibition stands, & storage rooms may all benefit from fire-resistant wood. It’s also an excellent solution for interior dividers between rooms and spaces in open-plan structures since the fire retardant effect improves building safety in the event of an emergency.


Because the roof and shingles, in particular, are susceptible elements of any structure, fire retardant wood is often utilized in roof construction & shingling. 

Fire-resistant wood adds an added degree of protection against wildfires, lightning, and even errant pyrotechnics from the neighborhood.

It also plays a significant part in the support structure & framing of buildings. A particular amount of fire-retardant materials may be needed in the building structure, & fire-retardant timber may be a cost-effective approach to fulfill and exceed local fire rules.

Residential Structures

Decks & balconies, rails, outdoor stairs, soffit, trim, and siding are all acceptable choices for fire-resistant wood in residential structures. 

Fire-retardant wood may even be regarded as a non-flammable product for these modifications, depending on local rules and standards, making the final structure more insurance friendly and also secure.

Projects Outside the Home

Furthermore, fire-resistant wood is the chosen material for wooden structures, workshops, garages, feed storage barns, and, most importantly, stables. 

Fire-retardant wood is frequently a better solution than standard conserved wood or fire-retardant coatings, especially in big agricultural and ranch environments.

Fire-retardant wood may benefit any structure near fire hazards such as standing trees, shrubs, or other natural characteristics. It’s also a suitable choice for structures that will house highly combustible items such as grain storage, sawdust, and other similar stuff.

Frequently Asked Questions(FAQs), “How to fireproof wood?”

How do you keep wood safe from fire and heat?

  • Keep wooden furniture away from radiators and vents. When wood is used to block heat sources, the likelihood of the wood being harmed by high heat is considerably increased.
  • Use a dehumidifier in the summer.
  • Use a varnish to help preserve wood objects from heat.

How do you make a wooden shed fireproof?

Adding insulation to sheds, summerhouses, and other similar structures may also assist avoid fires. 

Fire-resistant insulation, including fiberglass, should be put on the walls and roof of your wood structures in the summer to help keep the structure cooler and reduce the danger of fire.

How do you make wood cladding fire-resistant?

The use of flame-retardant chemicals on timber cladding may readily safeguard it against fire. These may be applied using a high-pressure impregnation method, similar to preservative treatment, or by brushing on the surface on-site or in a controlled manufacturing environment.

Is borax a good fire extinguisher?

Borax tends to slow the spread of flames, although it may also encourage smoldering or glowing. Boric acid, on the other hand, reduces glowing but has minimal impact on flame propagation. 

At a low temp (100 °C to 300 °C), boric acid catalyzes the dehydration as well as other oxygen-eliminating processes of wood.

Is foil fire-resistant?

Aluminum foil is nonflammable and only catches fire at very high temps. Aluminum foil will not catch on fire until it reaches a temperature of around 1220 degrees Fahrenheit (660 Celsius). 

Is it necessary to stain the wood before burning it?

For health and safety concerns, it is better to dye wood after it has been completely burned. You would be putting yourself in danger if you tried to stain before burning since burning stained wood releases toxic fumes into the air.

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