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Class A Fire Rating

Class A fire-rated materials offer the best fire resistance and protection to residents living in fire-prone areas.

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Fire departments in the U.S. respond to more than 1.6 million fire calls each year. These fires are responsible for numerous injuries, deaths, and damages amounting to billions of dollars. To protect homes and occupants, local building codes stipulate measures such as the use of fire-retardant materials and fire systems. 

You need to understand how different materials impact your home. Let’s delve into Class A fire rating and the type of materials that provide the best protection against accidental fires. 

What’s Fire Resistance? 

Fire resistance is the property of materials that enables them to prevent or retard the transfer of flames, hot gasses, and heat from a fire. 

Class A Fire Rating 

The Class A fire rating is the most stringent standard available for building materials. It’s usually assigned to retardants that have a flame spread rating of between 0 and 25. Any material with this rating typically has a lower flame spread and a better performance rating than Class B or Class C material.  

Materials with a Class A fire rating provide the greatest fire resistance. They are also effective against fires caused by ordinary combustibles like wood, cloth, paper, trash, and some plastics. 

Fire-Resistance Rating 

The fire-resistance rating is the length of time a specific material or element can withstand a particular fire test. It is usually determined by measuring the ability of a fire protection material or assembly to hold out against a normal fire.  

Sometimes, the fire rating is measured using set criteria that determine a material’s ability to perform a given structural function when exposed to fire. Other methods or procedures for determining fire-resistance include: 

  • Designs of elements that have fire-resistance ratings 
  • Design documentation from approved sources 
  • Comparison of the fire resistance of a building element and its design  

What Do Local Building Codes Say? 

The Virginia Residential Code (2015) requires homeowners to adhere to the same levels of safety regardless of materials. Buildings have to be designed to meet rigorous performance standards and incorporate both passive and active fire safety features. 

The Virginia Construction Code prohibits the use of combustible materials in concealed areas of a building except for Class A interior finish materials under section 803. Homeowners can install combustible piping with partitions. However, they must do so according to the provisions of the building code and the International Plumbing Code. Anyone who wishes to use combustible insulation or pipe covering or tubing in hidden areas has to comply with section 720.7 of the code. 

Construction Materials 

When you build your home or repair it, you should use ignition-resistant building techniques and Class A rated materials, which are non-combustible. Let’s look at the best materials for different parts of the home. 

Roof Coverings 

Various roof coverings have different fire ratings, with Class A providing the best fire resistance. Fiberglass shingles, concrete, asphalt, and clay tiles are perfect examples of Class A roof coverings. Some roofing materials have a “by-assembly Class A fire rating”. That’s another way to say builders can insert materials like aluminum, rubber products, and fire-resistant wood shake products between the roof sheathing and the covering to attain the rating.  

Wall Construction 

Whenever you’re erecting interior walls or partitioning non-symmetrical buildings, you should keep fire resistance in mind. Ensure that the builders create fire-resistant and smoke-tight walls with protected openings.  

Such walls will restrict the spread of a fire. Typical walls extend from the foundation to the roof and are structurally stable under fire conditions. When a structure collapses, it falls on either side without the wall collapsing. 

Below-the-Grade Areas 

Insulation requirements for the basement are the same as that of the crawl space. Their walls typically require three inches of continuous R-15 insulation on the interior or exterior walls. You can also use R-19 and R-13 cavity insulation (fiberglass) to cover the interior walls.  

Insulation has to start at the top of the wall and extend 24 inches beyond the finished grade level. A vapor retarder is recommended for an unvented crawl space. For the basement ceiling, use insulation that’s at least seven inches thick.   

Protecting Your Home 

Section 901.2 of the Virginia Building Codes, which cover Fire Protection Systems, requires homeowners to install, repair, and maintain their systems in accordance with the local code and the International Fire Code. Homeowners can also install any fire protection systems that are not required by the code, partially or completely. 

Insulation is an important aspect of heat retention and fire protection. Materials like vapor retarders, membranes, and single or multilayer foil insulation can also help you comply with local codes. 

While many homeowners use active fire suppression systems such as fire extinguishers and sprinklers, it’s passive fire protection that controls fires at the starting point. Fire-resistant walls, floor, and open space are all useful in containing fires and slowing down their spread. 

If you’d like to insulate low-lying areas like the crawl space or basement, talk to the experts at JES Foundation Repair. We’ll offer you a free estimate and recommendations after performing a thorough inspection of your home. We use ExTremeBloc™, which is durable insulation with a Class A fire rating.