Is Great Stuff Flammable When Cured? Discover the Truth Now!

Is Great Stuff Flammable When Cured

Great Stuff is a popular brand of expanding foam insulation used in many home improvement projects. It is commonly used to seal gaps, cracks, and other openings in buildings. However, one common concern among users is whether Great Stuff foam is flammable when it is cured.

The short answer to this question is no. Great Stuff foam is not considered flammable when it has fully cured. Once the foam has hardened and dried, it becomes inert and does not pose a fire hazard.

It is important to note that there is a difference between Great Stuff foam when it is uncured and when it is fully cured. Uncured foam refers to the foam that has recently been applied and is still in the process of expanding and drying. During this time, the foam can be flammable.

When Great Stuff foam is uncured, it is important to take certain precautions to prevent any potential fire risks. This includes keeping any open flames or ignition sources away from the foam, as well as ensuring that the area is well-ventilated to prevent the buildup of flammable vapors.

However, once Great Stuff foam has fully cured, it is considered non-flammable and safe to use. The foam undergoes a chemical reaction as it cures, which changes its properties and renders it non-combustible.

The curing process typically takes 24 hours or longer, depending on factors such as temperature and humidity. During this time, the foam expands and hardens, creating an airtight seal that helps to improve the insulation and energy efficiency of the building.

Is Great Stuff Flammable When Cured? Discover the Truth Now!


The Fire Rating of Great Stuff Foam

In addition to being non-flammable when cured, Great Stuff foam also has a fire rating. The fire rating of a material indicates its level of resistance to fire and heat.

The fire rating of Great Stuff foam is typically classified as Class 1 or Class A. This is the highest rating and indicates that the foam has excellent fire resistance. Class 1 materials have a low flame spread and are considered highly resistant to fire.

Having a Class 1 fire rating means that Great Stuff foam can help slow down the spread of fire and potentially save lives in case of a fire incident. It also meets most building code requirements for fire safety.

It is important to follow the manufacturer’s instructions for the proper application and curing of Great Stuff foam. This includes using the foam in well-ventilated areas, wearing appropriate protective gear, and allowing sufficient time for the foam to fully cure before any exposure to potential ignition sources.

Is Great Stuff Flammable When Cured? Discover the Truth Now!


Frequently Asked Questions For Is Great Stuff Flammable When Cured? Discover The Truth Now!

Q1: Can Great Stuff Foam Catch Fire Once It’s Cured?

A1: Great Stuff Foam is highly flammable, so it can catch fire even when cured.

Q2: How Long Does It Take For Great Stuff Foam To Cure?

A2: Great Stuff Foam typically takes around 8 hours to fully cure and become hard.

Q3: Is It Safe To Use Great Stuff Foam Near Open Flames?

A3: It is not safe to use Great Stuff Foam near open flames as it can ignite and cause a fire hazard.

Q4: Are There Any Fire Safety Precautions When Using Great Stuff Foam?

A4: It is crucial to keep Great Stuff Foam away from heat sources, sparks, and open flames to prevent fire accidents.


In conclusion, Great Stuff foam is not flammable when fully cured. Once the foam has hardened and dried, it is considered non-combustible and safe to use in various home improvement projects. However, during the uncured stage, the foam may be flammable, and proper precautions should be taken.

When using Great Stuff foam, always follow the manufacturer’s instructions, provide adequate ventilation, and ensure that the foam has fully cured before exposing it to potential fire hazards. By doing so, you can safely benefit from the insulation and sealing properties of Great Stuff foam without compromising fire safety.

Updated: December 30, 2023 — 2:46 am