Is Spray Foam Insulation Flammable? What You Need to Know

Using spray foam insulation in buildings and homes is becoming increasingly popular. But could this modern convenience put your safety at risk?

Insulation is an essential part of any construction project, but it shouldn't come at the expense of safety. It's natural to want to ensure the materials used are not hazardous.

This article will answer the question - is spray foam insulation flammable and provide additional information on important fire safety considerations with this type of insulation.

Is Spray Foam Insulation Flammable

Is Spray Foam Insulation Flammable?

Yes, just like other forms of insulation, spray foam insulation is flammable. However, it is treated with chemicals that make it fire retardant. The fire rating can differ from brand to brand, but generally, spray foam has a class 1 fire rating, which means the insulation can resist exposure to fire for one hour. 

What is Spray Foam Insulation?

Spray foam insulation, also known as spray polyurethane foam (SPF), is a type of rigid foam that expands to form an air-tight seal in your walls, floors, and ceilings. Its two primary liquid ingredients are polyurethane and an additive foam. When the two liquids come in contact, they mix to form an expandable foam that solidifies as it dries.

One of the advantages of spray foam insulation compared to other insulation material is its ability to expand up to many times its original size when sprayed onto surfaces. This allows for greater airtightness within walls helping to reduce energy loss and making homes more energy efficient. In addition, spray foam insulation can fill tiny gaps or areas around wires or pipes inside walls because of its expanding properties.

What Are The Types Of Spray Foam Insulation?

There are two types of spray foam insulation:

  •  Open cell spray foam
  •  Closed cell spray foam

Open cell spray foam (half-pound foam): Open cell is more flexible because it has more space between its cells and is the softer foam alternative. It provides excellent thermal insulating properties and helps reduce energy costs by preventing heated or conditioned air from escaping buildings. 

It also has superior sound-dampening properties and can help reduce unwanted noise between rooms and floors. In addition, it’s lightweight and ideal for hard-to-reach places. The downside is that it’s not the best solution for extreme temperatures, and application can be difficult because it’s quick drying.

Closed cell spray foam (two-pound foam): Closed cell is more rigid because it has little to no air space between its cells. It’s thicker and firmer, so it can help strengthen the integrity of the building it’s been applied to. 

Closed cell foam is widely used as insulation on foundations and other areas of a structure where a moisture barrier is required owing to its capacity to withstand moisture/vapor. It also has a higher R-value and longer life span than open cell foam. However, it offers less noise reduction and can be challenging to install evenly due to its rigidity.

Is Spray Foam Flammable

Is Spray Foam A Fire Hazard?

Yes, it can be. As mentioned, spray foam has a class 1 fire rating. If there's a fire outbreak, the product can withstand exposure to standardized flames for 1 hour without acting as an accelerant. At this point, firefighters have time to respond and extinguish any fire since the foam properties act as an ignition barrier and prevent the fire from spreading. 

However, this does not imply that the material is fireproof. It is fire retardant. So, some may wonder - is spray foam flammable after it dries? Yes, expanding foam is flammable, whether it is dry or not. Once there’s an ignition, cured foam can ignite at temperatures exceeding 700°F. 

What Happens Once Spray Foam Ignites?

Once spray foam insulation catches fire, it can be hard to extinguish. The foam itself burns quickly and generates large amounts of heat, smoke, and fumes due to the chemicals used in its production. Toxic gases and materials, such as carbon monoxide, isocyanates, hydrogen cyanide, carbon dioxide, and even nitrogen oxide, are released from the fumes. Inhaling these chemicals poses health risks.

How Can I Extinguish A Spray Foam Insulation Fire?

In a spray foam insulation fire, it is essential to exercise extreme caution. Do not try to put out the fire yourself. Instead, immediately evacuate people and pets from the area, close all doors and windows, and call 911 or your local emergency services for help.

If you must attempt to extinguish a polyurethane spray foam fire, you should use a Class B fire extinguisher rated for flammable liquids and gases. The easiest way is to cut off the oxygen fueling the flame by using a smothering agent like water fog or dry powder extinguishers

Smothering agents work best since they create an oxygen-free environment around the flames and can stop their spread quickly. However, smothering agents can be hazardous if combustible materials are nearby, so use caution when attempting this method.

Is Spray Foam Flammable After It Dries

Why Should I Use Spray Foam Insulation?

Spray foam is a superior product when it comes to insulation. Not only is it a fire retardant, but it has numerous other excellent qualities, including:

Unlike other traditional insulators, spray foam lasts longer. The polyurethane and isocyanate properties help the material stay intact without sagging and losing shape.

Energy Efficiency
Utility bills are a part of life, but an effective insulator such as spray foam can help ease the pain. Energy bills increase from cracks, air leaks, and outdated HVAC systems. But applying a spray on foam expands and seals air leaks and reduces lost air. In addition, its higher R-value creates an effective thermal barrier, contributing to better energy efficiency.

Deters Moisture And Most Growth
Moisture penetration can be a home’s worst enemy. Tiny cracks and crevices allow moisture pockets to develop and may contribute to mold and bacterial growth, damaging structures. Spray foam insulation is an effective filler and insulator to combat moisture. It also contains an inert polymer that serves as a “zero food supply” to bacteria and mold.

Spray foam is an eco-friendly insulator that reduces your carbon footprint by helping you consume less energy. It is an excellent alternative to fiber-based insulators like fiberglass insulation and cellulose insulation.

What Are The Risks Of Using Spray Foam Insulation

If you are considering using and installing spray foam insulation yourself, keep in mind that installation is a serious process that demands a qualified technician's attention. It's not an ideal DIY installation, as any mistake may cause combustion.

Also, safety precautions, such as wearing protective gear, must be observed. In addition, you should leave the building for at least 24 hours during installation and allow the foam to dry.

Risks associated with exposure to spray foam installation include:

  • Skin and eye irritation
  • Breathing problems leading to asthma attacks
  • Irritation of the nasal passageways
  • Throat inflammation
  • Chest pains and tightness

Final Thoughts

Back to the original question - is spray foam insulation flammable? Yes, but the product contains fire retardant chemicals, which, in the event of a fire, will give you time to call for emergency help so they can arrive and extinguish the flames before they spread.

Despite its potentially hazardous nature, spray foam insulation remains one of the best options for creating an energy-efficient and comfortable living environment. As long as you know its characteristics and take the proper steps to be safe, you should have no problem using this product in your home.