How to Fireproof Wood

Wood is a versatile raw material used in the construction, art industry, musical instruments, sports equipment, furniture, and so on. While it’s durable and long-lasting, you can’t ignore the fact that it is also prone to fire hazards.

Wood is highly flammable and it’s critically important to make it fireproof before using it in any woodworking project. That’s why I have come up with this guide that discusses different methods along with detailed steps to fireproof wood.

How to Fireproof Wood

If you’re working on a large or small woodworking project and need to make your material fireproof, you can use any of the following methods.

Using Commercial Fire-Retardant Product

Using fire retardant technology is the most common way to make wood fireproof. This method is usually used on a commercial level with the help of advanced machinery. However, you can use a fire-retardant chemical to make wood fireproof using the following steps.

Step 1: Dry Wood

The first step is to get the moisture out of the wood. You can place your wood logs under direct sunlight to let them dry naturally. But it’s a time-consuming process that can easily take weeks or even months. The faster and more efficient way is to place your wood into a kiln.

A kiln is like an oven that accelerates the wood drying process. Typically, a one-inch thick wood piece takes about 10 to 12 hours in a kiln to dry.

Step 2: Apply Fire-Retardant

Once the wood has dried, you’ll need to apply a fire retardant chemical to it. It’s a substance that slows down or completely halts the spread of fire. Use the following tips to apply the fire retardant to your wood.

1. Add the fire retardant chemical to a bottle with a sprayer.
2. Hold the nozzle of the sprayer about eight inches away from the wood surface.
3. Start spraying the chemical on the wood surface.
4. You can overlap sprayed areas to ensure complete coverage.
5. Let the fire-retardant chemical dry for a couple of hours.
6. Repeat the same steps at least a couple of times to make the wood fireproof.

It’s important to note that the fire-retardant chemical is applied in a retort chamber on a commercial level. A retort chamber is a big and expensive machine that creates a vacuum to apply fire-retardant chemicals on wood under pressure.

Applying this chemical at home using a sprayer won’t generate the same results. However, it’ll increase the resistance of your wood against fire to slow down the spread of fire.

Using Fire-Retardant Spray

This is the easiest method to make wood fireproof as you only need water and borax powder to complete it. This powder is resistant to fire and you can create and apply the fire-retardant spray to the wood using the following steps:

1. Add four cups of fresh water to a saucepan and place it on the stove.
2. Turn on the stove after selecting the highest heat settings and let the water boil. It’ll take about five minutes. 
3. Add 12 to 15 tablespoons of borax powder to the boiling water.
4. Use a rubber spatula to stir the mixture for 10 to 15 seconds.
5. Turn off the stove and remove the saucepan.
6. Let the mixture cool down and come to room temperature.
7. Grab a clean and dry spray bottle and transfer the solution to it.
8. Start spraying the solution over the wood and make sure that you cover the entire surface. 
9. Wait for 30 to 45 minutes to let the solution dry.
10. Spray the heat-resistant solution again. 

You’ll need to apply three to four layers of this solution to the wood surface to make it fireproof.

Don’t forget to dry your wood before applying the heat-resistant solution. You can use the same technique discussed in the first method for drying wood.

Using Fire-Retardant Solution

It’s a simple and easy method to make wood fireproof. You’ll need to mix zinc chloride, ferric chloride, ammonium phosphate, and boric acid with water to make this fire-retardant solution. Use the following steps to make and apply the solution to your wood in order to make it fireproof.

1. Add one cup of zinc chloride and a half cup of ferric chloride to a bucket. 
2. Pour about three liters of water into the bucket and mix the ingredients well. 
3. Now add six tablespoons of ammonium phosphate and the same amount of boric acid to the mixture.
4. Stir the mixture again to create a saturated flame-resistant solution.
5. Dip a clean paintbrush into the bucket and start applying the solution to your wood. You can use a spray bottle for the same purpose if you want to complete the process quickly. 
6. Make sure that you cover the entire wood surface and apply an even coat.
7. Let the wood dry for 30 to 40 minutes and reapply the solution using the same technique.

Three to four coats of this fire-retardant solution will allow you to make your wood fireproof. Make sure that your wood is dry before you start applying the flame-resistant solution.

Different Categories of Fire/Heat Resistant Woods

The heat resistance of wood is denoted by FSR (Flame Spread Rating). This rating indicates how effectively a wooden material will keep the fire from spreading on its surface. The flame resistance of wood is divided into three classes shown in the table below.

Final Words

Fireproofing wood is the best way to keep buildings and furniture safe from fire. Not only does it protect your belongings but it also ensures your and your family’s safety. I hope this guide will help you understand easy ways that you can use at home to fireproof wood effectively.