Intumescent Paint Costs- All You Can Ask About It!

Imagine if we could travel through time and ask our ancestors their opinion about our modern home! They would probably think that we live on top of a bomb. There are so many flammable things we keep by outside, that it’s a wonder how our home does not get ablaze. 

Luckily, as the amount of flammable material increased in our house, the technology to suppress it has also progressed. All of these technologies are crucial as death by fire is something that none of us wants. One such technology is intumescent fireproofing.

While it is very important for our safety, we are naturally also concerned about the cost. So, how much does intumescent paint cost?

In short, to paint a square foot of area you can expect anywhere from 4 dollars to 12 dollars. While the exact amount will vary depending on many factors, the realized cost should fall in this range.

Read this article to learn more about the intumescent paint costs and their functions. 

What is an Intumescent Paint? And Why Is It Used for?

Intumescent paint is a very special type of paint that is applied in buildings to make them more resistant to fire.

Anything intumescent essentially expands in the presence of heat. This creates an insulator of sorts. Intumescent paint works by the same principle. If intumescent paint is used in a building then the coating will expand when there is a fire nearby. 

So, essentially this works as an insulator. Doing so provides time to extinguish the fire before it spreads to the rest of the building.

Now, why does it work as an insulator? 

It expands because of how the chemical structure of intumescent paint is designed. The chemicals that make up the intumescent paint, in the presence of heat, expand and create a charcoal-like foam. This charcoal foam is the insulator that reduces the fire risk.

Intumescent Paint Costs in Detail

While we cannot compromise on ensuring safety, our safety measures need to stay within budget. In this regard, we need to know, “How much does intumescent paint costs”.

In short, expect to pay around 4 to 12 dollars to paint an sq foot of material. We know that 4-12 is a very big range to give. But unfortunately, without knowing the details of your particular situation, providing a narrow cost range is almost impossible.

This is because the cost depends on various factors like the VOC, expansion ratio, material quality, density, need for priming the surface, etc. In some situations, you will need to prepare the surface before you can apply the paint. Otherwise, rust will set in. This need for preparing the surface definitely drives up the cost.

Similarly, how much paint you are going to need is also a function of many other variables. These factors will be discussed later in this article. But for now, it is clear that the exact cost will vary depending on your situation.

However, the intumescent paint cost per square foot is unlikely to be less than 4 dollars and should not exceed 12 dollars per sq foot. 

How Much Intumescent Paint Do I Need?

How much intumescent paint you need will depend on the type of intumescent paint and the material you are trying to protect. For example, all materials are not equally good at spreading flames. So, easily flammable materials will require more intumescent paint than others.

So before applying intumescent paint contact your engineer or builder to know more about the material quality. Also, seek guidance from the intumescent paint company as they will be able to provide the best information depending on your particular situation.

However, there is a formula to determine the intumescent paint thickness i.e. the amount of paint that needs to be used. 

The formula says that the amount of paint you are going to need is equal to the product of performance, density, and surface. But to get accurate information on all of these factors it’s best to consult with a professional.

Two Intumescent Paint Fire Ratings You Should Focus On

So, now you know the importance of intumescent paint and how much it might cost. But before you go and buy paint, you should realize that all intumescent paints available in the market are not of the same quality.

So, how can you find the best intumescent paint out there? 

The answer is by looking at the fire ratings. Among many different types of fire ratings, two are most important for intumescent paint – ASTM E84 and ASTM E119. The ASTM stands for American Society of Testing and Materials.

The ASTM E84 checks for the spread of the flame. That means, how easy it is for fire to spread through the material. After the test, it gives each material a score from 0 to 200. A score of 200 means that there will be essentially no resistance. So, choose an intumescent paint that has a low score on ASTM E84 – preferably a rating from 0 to 25.

Another important rating is ASTM E119. It checks for how long the intumescent coating will provide protection. You will often see the result of this rating written in hours – 2 hours, 3 hours, etc. As a result the higher the score on this rating the safer it is for you in case of an emergency.

Can You Paint over Intumescent Coating?

Yes, technically you can paint over intumescent paint. That means, even if your building is intumescent coated, the regular color will stick if applied over it. However, whether the intumescent coating will work to protect you from fire is another case.

The most common intumescent paint is white-colored. So, if you decide to change the color and still keep the functionality of the intumescent paint intact (which we highly recommend) then it’s best not to choose any random color type. If you paint over the intumescent coating with some particular type of color then the coating will no longer be able to expand and fail to work as a fire protector.

So yes. You can color over an intumescent coating. But to keep the benefits of this intumescent fireproofing, talk to your intumescent paint provider and learn about the suitable color. If you paint with a suitable color type then you can not only change the color of your building but also keep the “fire-safety” characteristics of the intumescent paint intact. 


Here we answer some of the most common questions people have regarding intumescent paint. 

How Long Does Intumescent Coating Last?

How long an Intumescent coating will last in the presence of heat depends on the material it is used on. Intumescent paint is most commonly used on steel. On steel, the intumescent coating lasts for anywhere ranging from 60 to 120 minutes depending on the quality of the paint.  

At What Temperature Does Intumescent Paint React?

Generally speaking, intumescent paint reacts at 120 degrees centigrade or 248 degrees fahrenhites. At this temperature, the chemical components of the paint form a special reaction and turn into a foamy charcoal-like substance that works as a very good insulator.

Final Words

Now you can answer for yourself, “How much does intumescent paint cost?” As you already know it depends on various factors. But it will be in the range of 4 to 12 dollars. This might feel expensive. But remember fireproofing your house is an expense worth taking. You cannot put a price tag on your and your loved ones’ life.

Leave a Comment