What Are the Different Classes of Fires?

From buckling your seatbelt to making sure the chicken you’re grilling is fully cooked, we all take little steps to stay safer and better protected every day. And part of safeguarding our own wellness is extending safe practices to our surroundings – and in the case of your fireplace, protecting your home from an out-of-control fire is crucial.

Different kinds of fires demand different approaches for safer and more effective management. At The Chimney Guys, we understand that a fully-orbed approach requires attentiveness to general fire safety concerns – and reaches to specialized areas like chimney maintenance.

It’s our goal to use the knowledge we have of our broad range of fireplace services to help ensure your home remains safer from all potential fire hazards – including the sometimes-overlooked realm of chimney fires.

What Are the Classifications of Fires?

Not all fires act the same, so effectively fighting them requires some know-how about the different types of fires that can occur. Fires can be broadly grouped into five different types based on what combustibles are fueling the fire:

1. Class A: Solids. 
2. Class B: Gas or liquids.
3. Class C: Electrical Fires.
4. Class D: Metals.
5. Class K: Cooking grease or oils.

Class A fires are often called “ordinary” – though that doesn’t mean they aren’t hazardous – because the combustibles that fuel them can be found in many places. Wood, textiles, some plastics, paper, and other ordinary solids can accidentally ignite a fire that may rapidly spread. Water can cool these fires, smothering can deprive them of the oxygen they need to spread, or an extinguisher designed for class A fires can work to halt combustion.

For class B fires, an extinguisher will be designed to smother the flames or remove oxygen using foam, carbon dioxide, or dry chemical agents. Caution should always be used when handling flammable liquids and gases like gasoline, paint, butane, propane, and kerosene to prevent fires.

Class C fires must be suppressed using non-conductive materials to avoid the risk of electrocution. Using water to fight a fire involving live electrical equipment (such as appliances or wiring) is dangerous. Instead, dry chemical extinguishers are an appropriate choice.

Homeowners are less likely to encounter Class D fires, but they do need special attention as they can be tricky to extinguish. Metallic fires include materials like potassium, magnesium, and aluminum – and water can worsen the situation. Instead, dry powder agents can quell the flames instead of provoking a violent reaction.

Class K fires are linked to food preparation and can spread quickly. Water will exacerbate the problem rather than help it, but using a fire blanket (if the fire is small) or a wet agent fire extinguisher can be effective. These extinguishers will cool the fire and form a barrier to keep the fire from re-igniting.

Being prepared for any type of fire requires that you take stock of the hazards present in your environment and plan for the right response. For example, you’d want to keep an ABC extinguisher near your fireplace, but a Class K extinguisher would be the right choice for the kitchen.

What About Chimney Fires? What Class Are They In?

The five classes cover most scenarios, but there’s a type of fire that might not jump right to most homeowners’ minds: chimney fires. 

Chimney fires are as serious a threat as any other type of fire, yet they often fly under the radar. Although chimneys are designed to expel the hazardous byproducts of fire, it doesn’t necessarily mean they’re immune to the risks of them.

They particularly become at risk when creosote, a tarry product of incomplete combustion, is allowed to accumulate in the chimney flue over time – or when debris is able to enter the flue and either a) become a fire hazard or b) exacerbate fire risk by impairing good ventilation. When creosote ignites, it can lead to a chimney fire that could range from a smoldering fire to a full-blown, raging blaze.

Because chimney fires often involve creosote or other solid combustibles, they’d most often be classified as Class A fires.

How Often Do Chimney Fires Occur?

Chimney fires are more common than most people realize, numbering well into the thousands each year – although they can be hard to quantify, since it’s possible to suffer a chimney fire without even knowing it.

Some chimney fires spread to surrounding areas of the home, but others remain confined to the chimney before burning themselves out.

You may hear a chimney fire, notice the flames or excessive smoke pouring from the chimney, or smell the acrid scent of burning creosote during a chimney fire. If you do, reach out to the appropriate authorities right away.

But even a chimney fire that you don’t know occurred can cause significant damage to the structure of your chimney, so it’s important to have your chimney inspected regularly to identify and address deterioration or damage that may be present…before it worsens and compromises the integrity of your fireplace system or home, in general.

Prevention Is Key: Book Maintenance With Us

At The Chimney Guys, we want you to enjoy your home to the full. Part of that means securing the peace of mind that comes from knowing your system is running at its best and steps have been taken to minimize fire risk. Here are some steps you can take to better protect your home.

• Regular inspections and sweeping. Schedule annual chimney inspections with a professional you can trust – like us. Our certified technicians can identify structural damage, check for creosote accumulation, and assess overall chimney health. Coupled with routine professional sweeping, we’ll help you avoid conditions that could lead to a chimney fire.
• Burn only dry, well seasoned firewood, which will burn hot and clean – and thus reduce creosote build up.
• If yours is damaged or missing, have a chimney cap installed to keep moisture and debris, like leaves and nests, out of your chimney flue.
• Be mindful of ventilation. You need adequate airflow for your fireplace to operate optimally.
• Be fire-safe. Be sure all members of the family know the rules for safe handling of fire at age-appropriate levels, and that smoke and carbon monoxide detectors are in place and functional.

Get Started – Call Today

With some knowledge and simple preventative steps, your home can stay cozy, warm, and protected against uncontained fire. Call us today for more help and guidance in keeping your fireplace and chimney in great, tip-top shape!