Is Foam Board Insulation Flammable? 

This article will answer the question, “is foam board insulation flammable?”. It also covers several topics about types of foam board insulation, its benefits, and the precautions for safely handling foam board insulation.

Is Foam Board Insulation Flammable?

Yes. Foam board insulation is flammable. When ignited, rigid polyurethane and polyisocyanurate foams produce high heat, dense smoke, and gases that are unpleasant, combustible, and poisonous.

On the other hand, foam board insulation is designated as a “class 1 hour fire rating,” which implies that the material can survive exposure to a standardized fire for one hour. 

This rating indicates that the material is safe. This suggests that it can be used to help control the spread of a fire and that it will not, in any case, operate as an accelerant. 

Ratings for a structure’s ability to sustain a fire simulation are often given in terms of the number of minutes or hours it can remain standing.

What Is the Definition of Foam Board Insulation?

A Foam board is a board with a light, robust material and easy to cut. The foam board is constructed of two sheets of matte textured paper with a center layer of polystyrene inside.

The fireproof quality, also known as fire resistance, signifies that the material in question is not combustible and can therefore withstand the effects of fire as a direct result of this fact. However, there is currently no such high-quality insulation on the market.

A substance is referred to as a fire retardant if it can reduce or halt the rate at which a fire could spread. This is conceivable because the foam board insulation contains preservatives, which reduce the flammability of the fuels and may slow down the rate at which they burn.

What Are the Benefits of Using Foam Board Insulation?

Some of the advantages of using foam board are:

  • A notable benefit of using this material is its relatively low cost. It can assist in the reduction of costs, hence resulting in monetary savings. Save money on your heating and cooling bills while improving the home’s climate and saving money overall.
  • Insulating your home with foam board can reduce your monthly energy expenditures by as much as 30 percent and give your heating and cooling systems the break they require.
  • Sound can travel throughout your home due to the gaps and fissures that exist within your walls, as well as those that are located around your windows and doors.

The background noise level can be reduced, and a more comfortable living environment can be created using foam board insulation to fill the cracks and crevices.

  • Reduce the humidity to stifle the spread of mold by making the environment less humid.
  • Mold thrives in moist conditions, particularly those in which there are cracks and fissures all around a property and in which the relative humidity level remains elevated. 

As a result, the surfaces of your windows may occasionally become covered in condensation or even frost.

  • Warm air with a high moisture content rises, so the ceilings and the attic become soaked entirely in moisture.

This might result in the growth of mold, in the long run, can result in the rotting of wood, damage to the home, and possibly even health problems for allergy-prone family members. Foam board insulation prevent this damage.

  • As a protection from the flames and the smoke, flames have a more difficult time moving from one spot to another when a fire-blocking foam board is present because it impedes oxygen flow.

Because of the spaces around your pipes, electrical cables, and outlets, oxygen can freely flow from one room to another in your home.

If there is a fire, utilizing a fire break that blocks the flow of oxygen offers you crucial additional time to escape to safety if there is a fire. Because oxygen is necessary for the spread of fire.

  • Foam board is easy to stick to the wall because it is lightweight, and you can easily use adhesives such as double-sided tape to attach it. But you need to remember that do not use sealants that might leave permanent scars on the surface of your foam board.
  • Foam board has lightweight qualities since the board is built of lightweight foam. This can offer you a diverse material that is easy to move wherever. Foam board is also one of the most excellent solutions for household use.
  • The shape of the foam board can be immediately printed on it and then cut according to the body and design you want, making it easy to alter it according to your needs.

What Kinds of Precautions Should Be Taken When Working with Foam Board Insulation? 

It is important to receive any specific instructions before beginning use.

  • Keep a safe distance from open flames, sparks, heat, and scorching surfaces.
  • It is essential to avoid spraying an open flame or any other source of ignition when using this product.
  • At no point in time, including after use, can the pressurized container be pierced or burned in any way.
  • It is important to remember not to breathe in any dust, fumes, gas, mist, vapors, or spray.
  • Keep a safe distance from them if you are a breastfeeding mother.
  • It is essential to give one’s skin a thorough cleaning after handling.
  • When using this product, ensure you are either outside or in a well-ventilated space.
  • Put on some gloves that will shield your hands.
  • If there is not enough ventilation, you must wear protective gear for your lungs.
  • Ignition can originate from a variety of sources, including sparks and open flames, among other things. As a result, you should avoid them as much as possible.


Foam board insulation is classified as flammable material. Safe handling precautions should be conducted to avoid flammability risks.

Frequently Asked Question (FAQs): Is Foam Board Insulation Flammable?

Is it safe to insulate with foam board?

When possible, you should avoid foam insulation, whether it comes in board form or as a spray. Insulations of foam typically contain highly toxic flame retardants, and spray foam typically contains isocyanates that can trigger asthma attacks.

 If you have no choice but to use foam insulation, steer clear of options that require reaction on site, such as spray foam.

Can foam board be stored in the open air?

According to the results of various tests, these laminated boards have a relatively high level of resistance to the deterioration caused by UV rays. 

Any foam board insulation exposed to the sun for more than thirty to sixty days at the very maximum should be covered. In most cases, that time is sufficient to finish the external walls.


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