How Do You Make Heat Resistant Wood?

Heat Resistant Wood

Wood is the most stylish and durable building material for your home but, it is always prone to heat and fire. Or what if you’re building a wood project that will likely have hot items on it. So, how do you make wood heat resistant? I did some research and this is what I found. 

No doubt wood is the most versatile material but we can’t neglect the fact that it is always prone to fire hazards. Keeping this fact in mind, wooden structures and materials need to be made heat resistant. Fortunately, there are various methods to make the wood completely heat resistant. However, most of these procedures are a bit expensive as they require costly materials and professional applications. But here is great news, to help you save some money, there are a few DIY-methods for making your wood heatproof. 

The methods here will involve making sprays of simple coating mixture using some easily available chemicals that will help retard the heat. Although these methods will not completely make the wood heatproof, these will provide enough resistance to bypass any upcoming hazard. 

Below is the first DIY method for making the wood heat resistant:

Method 1: DIY Heat Resistant Wood Spray

Things You Will Need 

  • Bucket 
  • Zinc chloride 
  • Ferric chloride 
  • Boric acid
  • Ammonium phosphate 
  • Spray bottle 
  • Gloves and Mask

You can get all these chemicals from farming or gardening supply stores nearby you. 

Step 1: Take a bucket and fill it with about 2 quarts of tap water. 

Step 2: Now mix about 1/4 cup of ferric chloride, 1/2 cup of zinc chloride, and finally pour 4 tbsp each of ammonium phosphate and boric acid. Stir all these chemicals nicely using a clean and dry wooden stick. Don’t touch this solution with your bare hands, wear gloves. 

Step 3: After mixing the ingredients nicely, pour it into a spray bottle. You can even paint it on the wood if you don’t have a spray bottle. 

Step 4: Finally, spray at least 2 to 3 coats of this prepared heat resistant solution to your wood. Same goes when using a paintbrush. Let it dry and, voila you have a fire and heat resistant wood!

While this method and the next method we are sharing will not make the wood completely fireproof, these will lower the possibility of ignition. Having said that, here is another simple method to make your wood heat resistant. The below method is an alternative to the method above, in case you don’t have an access to any chemical ingredients it requires. This method is equally helpful and quick. So, without wasting much time, let’s begin! 

Method 2: DIY Heat Resistant Spray 

Things You Will Need:

  • Borax or sodium borate 
  • Measuring cup
  • Measuring spoon 
  • Spare Saucepan 
  • Container for storage 
  • Paintbrush/spray bottle for the application 

Step 1: The trick is to prepare a saturated solution. For this, take about one cup of water in the saucepan and bring it to a boil. 

Step 2: Turn off the flame and add about 2 and a half tbsp of Borax to this boiling water. Now, stir the solution until Borax dissolves completely. 

Step 3: Let this solution sit and come to room temperature. After a few minutes, you will notice that some of the Borax has settled out at the bottom. This is completely normal and the clear liquid you see at the top is your heat retardant mixture. 

Step 4: Now, simply fill your spray bottle and the storage container with this clear solution and follow the next step on how to use it. 

Step 5: Take the wood which you need to protect and wet it really nicely. Now spray the solution generously. Allow it to dry and apply a few coats again. The idea is to let the solution soak into the wood thoroughly. 

You will need a good amount of solution, so make sure to prepare it in a large batch. 

Step 6: Finally, allow the subject to dry completely and protect it from moisture. Any contact with water will wash off the solution. 

So, these were the simple methods with which you can make your wood heat resistant on your own. But these methods are not permanent. As we already mentioned, any contact with water or moisture over time will take this solution off. So, in order to make wood permanently heat and fireproof, you need to take professional help. 

One of the best ways is to use a fire-resistant coating. This can be applied on any wooden surface including wooden walls, articles, furniture, floor, and ceilings. It is usually a clear coating, so it doesn’t mess with the aesthetics and lets the actual character of the wood shine. However, this kind of treatment is often expensive because it mainly needs a professional application. 

What Is Fire Retardant Coating or Paints? 

Fire retardant coating and paints are the special types of materials that are very crucial for protecting the wood from heat and fire. These types of paints are widely used in the wooden industry for protecting wood-finished homes. You can easily get them from any home depot. 

One important thing to keep in mind while purchasing the fire-resistant paint is it should meet the safety standard BS 476 when it is used for residential and commercial buildings. 

How Fire Retardant Paint Works? 

Fire retardant paints work by forming a protective layer on wood that protects it during a fire. Basically, the paint swells up and forms a foam-like layer by using the energy during foaming. When this happens, it protects the underlying wooden surface by insulating it. Not just that, when the wood is treated with fire retardant products, it offers other benefits like decreased smoke production, lower ignition time, and decreased flaming droplet formation. Moreover, a fire retardant treated wood offers more time for the people to escape during a fire episode. 

What Type of Wood is Heat Resistant?

The engineers and architects lay stress on using the heat resistant wood in the commercial and domestic buildings with insufficient fire safety measures. So, to safeguard the life of the public, heat resistant wood is used. 

Heat resistant wood is generally made of lumber, shakes, plywood, and shingles which are treated well with the fire-retardant coating which not only protects it from fire but also takes care of wood at higher temperatures. 

It offers resistance to the ignition of wood and also the spreading of flames. Moreover, the selection of heat resistant wood depends on the purpose and project it is going to be used on. 

Below are the different categories of heat resistant woods according to the specifications set by a majority of authorities. 

Class A Heat Resistant Wood 

The heat resistant wood in this category is popularly known as an I class woods. This type of wood doesn’t show any ignition during a continuous fire for at least 30 minutes. The flame spread index of Class A wood is also less than or equal to 25.

For those who don’t know, a flame index is basically the capability of wood to resist the flame travel on a wooden surface. Further, the flame index of untreated wood is 100 which shows how fast it will ignite after coming in contact with fire. 

Class B Heat Resistant Wood 

Class B heat resistant wood is also known as class II wood. This wood usually has a flame spread index between 26 and 75. You can upgrade any untreated wood at your home to the class II category by simply applying a fire retardant coating over the top of latex paint. 

Class C Heat Resistant Wood 

Class C or Class III woods falls under the lowest category. These generally have a flame spread index between 76 and 200. This wood is twice as flammable as any non-treated lumber. 

Reinforced Heat Resistant Wood

The heat resistance of wood is usually calculated by the calculation of fire rating. So, the heat resistance of wood can be upgraded by incorporating a layer of gypsum board. For example, suppose the heat resistance of a wooden wall is 20 minutes. In order to upgrade it to 65 minutes, a gypsum board can be added, which increases about 30 minutes of heat resistance. Moreover, the wood stud wall can be insulated using fiber material which will add extra 15-minute protection from heat. 

What is The Least Flammable Type of Natural Wood?

Talking about the natural woods, the majority of the hardwoods are the least flammable. These include mahogany, oak, walnut, teak, and maple. The reason behind this is that the hardwood is denser as compared to the other types of wood. So, when they are subjected to heat and fire, they will burn slowly. 

These are some facts and tips on how to make the wood heat-resistant. We have shared detailed information on making a wood fire and heat resistance. While the DIY methods are great, they are not permanent. So, in order to make a wood completely heatproof, it is recommended to take professional fireproofing treatment. 


Leave a Comment