When we started talking about climate change, the biggest concern was the planet getting warmer. While this is one side effect, there are other results that have taken many people by surprise, including the growing number of intense and deadly wildfires burning around the globe.
In regions like the Pacific Coast of the U.S., wildfires aren’t unheard of. But in regions like Greece and other parts of Europe that don’t normally experience wildfires, they can be devastating — both because of the fires themselves and because the countries don’t have the emergency services necessary to manage these blazes.
Fire-resistant buildings will become a necessary part of the rebuilding process, as these wildfires become more common every year. What goes into making a building fire-resistant? Can builders take any steps to reinforce existing structures to make them more fire-resistant?
Understanding How Fires Move
Before we can start creating fire-resistant buildings, we need to understand how fire moves, both indoors and out. Fire requires two things to spread: fuel and oxygen. If they have both available, they will spread exponentially.
In the case of a wildfire, the blaze will follow the food source and the wind can pick up embers and spread them beyond the edges of the fire. Indoors, the flames will follow things like wires and ventilation shafts. Anywhere that encourages airflow can encourage the spread of fire.
Fire Resistant vs. Fireproof
Ideally, homes and businesses in wildfire-prone areas would be fireproof. But what is the difference between that and fire-resistant materials?
In all technicality, the two terms can be used interchangeably, because when it comes down to it, there are no truly fireproof substances. At least none available commercially. Everything will burn if the temperature is high enough. The purpose of fireproof and fire-resistant materials is to prevent the fire from being able to spread long enough for homeowners or fire crews to stop the blaze.
Intumescent paint, for example, is capable of protecting steel for up to 120 minutes, but it needs to be installed during the construction period to ensure every surface is covered. This is just one example of fire-resistant construction. What other changes can you make to improve fire resistance?
Five Types of Construction
When talking about fire resistance, building construction can be broken down into one of five types depending on the materials they’re made of and how resistant those materials are:
● Type 5 buildings are wood-framed and can be incredibly combustible under certain circumstances.
● Type 4 buildings are typically older and use thick lumber or heavy timber for their structure.
● Type 3 buildings are ordinary, and you’ll usually find them with non-combustible walls but wood-framed roofs.
● Type 2 buildings are considered non-combustible, constructed with tilt slab and reinforced masonry walls.
● Type 1 buildings are primarily high rises, constructed with concrete and steel protected with things like that intumescent paint we mentioned earlier.
Most standard homes are Type 3, and those wood-framed roofs make them susceptible to wildfires.
Creating Sealed Building Envelopes
Building envelopes came about as a tool for improving energy efficiency and reducing heat leakage by creating a separation between the interior and exterior of the building. These can also be a valuable tool for preventing fire spread and making a building more fire-resistant. It’s also wise to include things like roofing assemblies that prevent fires, and vents designed to keep flames from following the movement of the air and traveling along with it.
These sealed envelopes help increase building fire resistance by limiting the paths the flames can follow. It won’t prevent fires, but it will make it easier to escape them and help limit the damage that can occur once they start.
Choosing the Right Materials
There are four primary properties that define fire-resistant materials:
1. They don’t disintegrate under extreme heat.
2. They don’t expand when exposed to extreme temperatures.
3. They don’t catch fire easily.
4. They don’t lose their strength when on fire.
The typical lumber that appears in most construction projects does not include any of these properties, so would not be considered fire-resistant. Adding a roof coating to asphalt shingles or metal roofing may help increase the fire resistance of a structure and may improve longevity, but it isn’t a perfect solution.
Things like stone, brick, and concrete, on the other hand, can be fire-resistant because they won’t fall apart in the event of a fire — at least, not immediately.
Fire-Resistant Building Techniques
Fierce and dangerous wildfires are a fact of life and, thanks to climate change, they will continue to get worse. All we can do, other than getting out of their way, is change the way we look at construction and take steps to make our structures a little more fire-resistant.
Evelyn Long is the editor-in-chief of Renovated, a real estate and construction resource for industry professionals.