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What Is a “Class A” Fire Rating?: Fire Resistance Building Codes

Just like water, fire can be a great ally as well as our worst enemy. Some estimates suggest that fire departments across the country respond to over 1.6 million emergency calls every year. Unfortunately, these emergencies don’t always end happily. Fires are responsible for countless injuries, deaths, and property damages that cost billions of dollars. 

So, how do we protect ourselves from fire-related accidents? Local building codes vouch for the use of fire-retardant materials and systems. But before you purchase and install one of them in your home, it’s essential to understand how they work. Therefore, we’ll cover all the necessary details to inform you about their use and how they’ll provide you with safety in the future.

What Is Fire Resistance? 

Before we go any further, we should explain what fire resistance means. The term fire resistance refers to the ability of materials to prevent or diminish the impact of flames, hot gasses, and heat from a fire. In the construction business, we differentiate three classes of fire ratings: Class A, Class B, and Class C. 

Class A Fire Rating 

When it comes to building materials, Class A gets the job done. It’s the most demanding standard available in the industry. As such, manufacturers of construction materials will assign it to retardants with a flame spread rating of between 0 and 25. 

This means that any product/material with this type of rating will have a lower flame spread and will offer better performance than the other two classes (B and C). They’re the best of the bunch and are pretty effective against burning wood, cloth, paper, and plastic. 

Fire-Resistance Rating 

Every quality construction material has a fire-resistance rating. It refers to the length of time a particular material or element can oppose a particular fire test. The technicians determine it by measuring its durability against a normal fire. The testing process includes a set of criteria that specify the material’s ability to withstand fire while performing its structural function. The tests will also include other methods such as: 

  • Inspecting the design of the product with a fire-resistance rating 
  • Research the documentation from the manufacturers 
  • Compare the design and purpose of the fire-resistance product 

The Requirements of Your Local Building Code 

When talking about the Class A fire rating, it’s key to mention the Michigan building code and its requirements. The local building code is a set of rules that requires buildings and other structural elements to be up to certain standards. The purpose of a local building code is to maintain public safety and health at the highest level. 

That said, you are required to follow the same safety standards no matter which materials you intend to use. Construction crews need to build structures that will meet set performance standards and include active and passive fire safety features. Active fire safety means considering protection that will help extinguish a fire. On the other hand, passive features will prevent the accident from happening in the first place. 

The Michigan building code prohibits you to use ignitable materials inside the structure if they don’t have a Class A fire rating. This is because all other fire ratings don’t offer enough safety to structures and people inside during a fire situation. Yet, a homeowner can incorporate flammable piping with partitions if they do it according to provisions of both the building and international plumbing code. 

Construction Materials 

It’s important to state that when building or repairing a home, you should always use non-flammable, Class A fire-rated materials to increase your safety. In what follows, we’ll point out some of the best materials with these features that you can use for different parts of your home. 

  • Roof coverings: Not all roof coverings will have the same fire rating. Therefore, it’s best to look for ones with a Class A tag. These include fiberglass shingles, concrete, asphalt, and even clay tiles. In case you come across roofing materials that have a stamp that says they’re Class A assembly fire-rated, don’t worry. This is just a fancy way of saying you can insert other materials between them, and they’ll still maintain the highest standard. 
  • Wall construction: Walls are no different when it comes to keeping an eye on fire ratings. This is especially true for interior walls or while partitioning a non-symmetrical building. You should make sure construction crews build fire-resistant and fire-tight walls without loose openings. This will ensure that the walls won’t collapse in the event of a fire, even if the rest of the structure caves. 
  • Bellow-grade areas: Both basements and crawl spaces need to meet insulation requirements to be fire-resistant. Bellow-grade area walls should have three-inch R-15 insulation on either the exterior or interior. You can also use R-19 or R-13 cavity fiberglass to cover the interior walls. 
crawl space insulation with a class a fire rating

The insulation should spread from the top to the bottom with a 24-inch extension beyond the grade level. We would also recommend a vapor retarder if you have a crawl space without vents. If you have a basement, it’s best to insulate its ceiling with at least a seven-inch thick cover.

Keeping Your Home Safe 

The local building code in Michigan requires you to install, repair, and maintain your fire protection system accordingly. You can also add to it by installing other systems that are not mandatory if you want more safety. Either way, it’s key to have proper insulation as this will help with heat retention and fire protection. You should check out materials such as vapor retarders, membranes, and single or multilayer foil to meet the local building code requirement. 

Although active fire suppression systems sound more attractive to regular homeowners, it’s the passive ones that will do the best job. Prevention is always better than the cure and passive systems will control the fire as it starts to light up. Therefore, we suggest that you consult professionals about fire-resistant walls, floors, and open spaces. 

If you’re looking to insulate your basement or crawl space, look no further than FSM in Michigan. Our team will come to your home and inspect the state of your lower-grade level for free. Afterward, they’ll offer solutions that include Class A fire-rated materials to ensure your family’s and home’s safety. Contact us now to schedule a free inspection and prevent any fire-related accidents in the future by being proactive. 

Leah Leitow

Leah Leitow

Content Writer

Leah is a Content Writer for Groundworks with nearly ten years of experience working in the foundation repair industry. Her experience ranges from working with homeowners to find the right solution to training inspectors and staff. In her background as a Michigan journalist, she gained invaluable insight into people's lives throughout our state. Leah lives in metro Detroit with her husband and two sons.

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