How Do You Make Wood Heat Resistant?


Is there any way to make wood heat resistant? Wood being a flammable substance, it’s only natural that you want your investment to be safe from fire, considering wood is used for a multitude of purposes(from construction to furniture). Read on as we highlight a few ways you can make wood heat/fire resistant.

The easiest and quickest way to make wood heat resistant is to coat it with a heat resistant coating. The coating can be bought or you can make it yourself at home. You apply the coating to the wood using a brush by evenly distributing the primer over the surface, after you let it dry, your wood will be much more heat resistant.

Certain types of woods are naturally heat resistant so you can use them if you require more heat resistance than just a coating. Azobe, Birch, and cedar are a few types with high heat resistance.

Another type of wood named as Fire Retardant Treated (FRT) is wood treated with special chemicals and made fire resistant. This type of wood is used at the commercial level for big construction projects which are required to meet certain standards for fire safety.

The Best Way To Make Your Wood Heat Resistant

There are certain fire retardant coating available in the market which make it easy to make any wood heat resistant. Depending on the type of wood you need to treat and the expected level of protection, the use of coating will vary. First, you should decide whether you want a home based or commercial solution.

For commercial products make sure to read and follow the manufacture guidelines for the required results. Whether you are using a home based or commercial solution make sure the wood is dry before application. Then using a spray bottle spray the whole wood evenly. Let the wood dry completely and you got your heat resistant wood ready.

There are many different types of coating paints or varnishes for wood which provide instant heat protection for wood. Their easy availability, ease of use and being relatively cheap is what makes them the best method to give any type of wood decent heat resistance.

Below is a demonstration of how heat resistant coating protects wood from fire:

As you can see in the video above, the heat resistant coating stops the wood from igniting while the unprotected wood ignites almost instantly. Not only does the coating stop it from igniting, the coating chars the surface of the wood in order to protect the wood from catching fire.

The protection lasts for at least 30 minutes even when the flame is directly applied. This means even if a fire source comes in contact with heat resistant wood it will not catch fire straight away thus protecting the whole premises from fire hazards. This also means you can use such wood as a shield in case of a fire to escape.

Pick Naturally Heat-Resistant Wood

Different types of wood are classified as class A, B or C depending on their level of heat resistance. The heat resistance is calculated by calculating the time the wood takes to burn and the flame spread index. The time to burn takes into account the minutes it takes for the wood to start burning and the flame spread index measures the travel speed of the flame over the wooden surface.

Class A or I has the highest level of fire resistance. For a wood to be classified as Class A it has to have an ignition time of minimum thirty minutes and a flame spread index of twenty five or less.

Class B or II has a flame spread index of 75 or lower. By applying a fire resistant coating to any wood you can upgrade it to class B.

Class C having the lowest level of heat resistance with a flame spread index of 200 or lower.

The species of Ironwood/hardwood is known as the wood with the highest level of heat resistance naturally. Azobe wood which is a type of ironwood has a higher ignition time so therefore it is known as the wood with the best heat resistance. It is top-grade if you are looking for the best quality fire or heat resistant wood.

Most well known hardwoods such as mahogany, oak, maple and walnut are the ones with the highest fire resistance.

Hardwoods are naturally more heat resistant due to their thickness and density. This ensures that they take some time to burn when subjected to heat or fire.


The Best Coating For Heat Resistance

One of the best fire retardants is the Fire Retardant Spray made by DRI-ONE. The spray can be used on wood and fabric and is classified as class A.

You don’t need to dilute or mix the substance with anything. The brand is very trusted and has a good history working since 1958.

Check the price and more information about them on Amazon.

Is It Possible To Make Wood Fireproof?

You are probably wondering if heat resistant or fire resistant wood is fireproof or if it is possible to make it fireproof. The answer is no, even Class A wood with the highest level of heat resistance would eventually burn if it’s put in fire long enough. Making wood heat resistant helps increase the amount of time it takes for the wood to ignite.

Based on the coating used, the ignition time of wood can be a few minutes to hours. The main reason wood is made heat resistant is in order to minimize damage in case of a fire and while also decreasing the chances of the fire spreading.

Fire resistant wood treated with special coating works by creating bubbles in the wood when it comes in contact with fire and chars the upper surface of the wood. These “bubbles” keep the wood from igniting for a set amount of time by insulating it. Therefore wood being a flammable material it is not possible to completely fireproof even class A wood which has the highest heat resistance.

Final thoughts


As you have seen, we have highlighted certain ways of giving wood fire or heat resistance. The easiest way is of course to apply a fire-resistant coating on any type of wood to increase its heat resistance. The other is to make a coating at home with certain chemicals however it is recommended to utilize the many professional commercial coating solutions available in the market for a more permanent result rather than home made solutions.

The other two methods to acquire heat resistant wood is to either buy FRT wood or to buy the hardwoods known for their high heat resistance. FRT wood especially is utilized for larger construction projects and is of course quite expensive as a result. For small home based projects it is better to use the heat resistant coating solutions which are readily available and can be used by anyone while being relatively inexpensive.

Martin Swizz

Hi! This is Martin, I like to research, experiment, and learn new things related to wood carving and other kinds of woodworking.

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