Residential fires kill more than 2,500 people per year in the United States alone. And most fatal fires occur when people are asleep in their homes, as smoke can lull a person into a deep slumber.
Ever wonder how your walls would protect you? While no practical building material is truly fireproof, well-constructed houses and buildings can help prevent such tragedies by using materials that are relatively fire-resistant.
Consequently, it’s not a question of whether a fire can damage a structure, but a question of when. It simply takes longer for fire to affect fire-resistant materials. The key is to construct a building in which a fire would take effect slowly, allowing the occupants plenty of time to escape. This is also why materials themselves are rated in respect to how long it would take fire to affect its structural abilities. Even heavy timber can be considered fire-resistant. It’s combustible, however, while metals like aluminium or steel aren’t combustible — instead, they tend to buckle under intense heat.
We’ll explore some of the best building materials for preventing and impeding a raging fire.
Fire-resistant Glass for Windows
Windows, important for visibility and light, can nonetheless be a fire hazard. Even before a window is in direct contact with flames, the intense heat of a nearby fire can cause the glass to break. And a broken window allows flames to enter a building easily. In addition, the heat from a fire outside might be enough to simply ignite flammable items inside a home without direct contact.
To protect your house, consider installing fire-resistant windows. One example is dual-paned glass windows, which, in addition to providing energy efficiency, also double the time it would take for the fire to break the windows. The outer layer will break first before the inner layer. Tempered glass, which is heat-treated to make it about four times stronger than regular glass, is also effective.
Though they don’t provide visibility, glass blocks are extremely fire-resistant while still providing light. Perhaps the best is wired glass, which is tempered glass with metal wire reinforcement. Doors that require fire resistance but also visibility often incorporate wired glass windows.
It’s also wise to note the importance of window framing. Steel framing offers the best fire protection, followed by wood and aluminium. Vinyl is the least effective.
On the next page, find out which noncombustible material makes it harder for fire to spread.
Adding Fire Protection
Structurally sound building materials, like steel, that don’t have great fire-resistance ratings, can be protected from fire with flame retardant seals using foam, chemical or cementitious-based products.
Concrete, one of the most common building materials, is also an excellent fire-resistant material. It is non-combustible and has low thermal conductivity, meaning that it takes a long time for the fire to affect its structural, load-bearing ability, and it protects from the spread of fire. It’s actually significantly more fire-resistant than steel and often used to reinforce and protect steel from fire.
However, it’s important to note that not all concrete is created equal. It consists of cement and aggregate, and the particular kinds of aggregate materials used can vary, as well as the amount used. Aggregate can make up 60 to 80 per cent of the concrete’s volume. The exact fire-resistance properties change depending on the type and amount of aggregate used. Natural aggregates tend not to perform as well. Moisture in the aggregate can expand when heated, causing the concrete to sinter after long exposure.
Concrete is often listed as among the best fire-resistant roofing materials, too. And you shouldn’t overlook the roof as essential in fire protection, since it’s extremely vulnerable to sparks blown from wildland fire.
Stucco is a plaster that has been used for centuries for both artistic and structural purposes. Modern stucco is made of Portland cement, sand and lime, and it serves as an excellent and durable fire-resistant finish material for buildings. It can cover any structural material, such as brick or wood. It usually consists of two or three coats over the metal reinforcing mesh. A one-inch (2.54-centimetre) layer of stucco can easily lend a 1-hour fire rating to a wall [source: Nazarro].
Roof eaves (overhangs) are a fire hazard, but they can be protected with an encasement of fire-resistant material. Stucco is often recommended as one of the best materials for boxing in hazardous eaves.
Stop Fire and Stay Stylish
Because of the versatility in finishing techniques, stucco can come in various colors and textures. This means that it’s easily adaptable to various architectural styles, including Prairie School, Mediterranean, Tudor and Southwestern. This way, you don’t have to sacrifice beauty for practical fire-resistant protection.
Many structural materials will require underlying gypsum sheathing in order to achieve a good fire-resistant rating, and the gypsum board is the most commonly used fire-resistant interior finish. Gypsum board, also known as drywall, consists of a layer of gypsum sandwiched between two sheets of paper. Type X gypsum board is specially treated with additives to further improve its fire-resistive qualities.
The paper on the exterior of the type X gypsum board burns slowly and doesn’t contribute to fire spread. In addition, the gypsum board has a noncombustible core that contains chemically combined water (in calcium sulfate). When affected by fire, the first thing that happens is that this water comes out as steam. This effectively impedes the transfer of heat through the gypsum board. And even after the water is gone, the gypsum core continues to resist fire penetration for a time. Builders often use multiple layers of gypsum board to increase the fire-resistance rating.
If we learned anything from the popular children’s tale of the “Three Little Pigs,” it’s that you should make your house out of brick. This isn’t such bad advice. Brick is not only resistant to a big bad wolf’s huffing and puffing — it’s also resistant to fires. The brick is used for houses, but also for Driveway Block Paving.
As bricks are made in a fire kiln, they’re already highly resistant to fire. However, it’s true that individual bricks are much more fire-resistant than a brick wall. A brick wall is held together with mortar, which is less effective. Nevertheless, brick is commonly cited as among the best building materials for fire protection. Depending on the construction and thickness of the wall, a brick wall can achieve a 1-hour to 4-hour fire-resistance rating.
So, although some materials are more fire-resistant than others, several factors might influence a builder’s decision, including cost-effectiveness, ease of installation and climate.
Unfortunately, brick can be expensive and heavy compared to other building materials. It’s also not very effective at insulation, hence requiring supportive insulating materials to make a building energy-efficient.
How is concrete made?
Few professions are as unappreciated as that of the gangland concrete shoe cobbler. Maybe you’ve never had to send a rival mobster to the bottom of the East River and, therefore, can’t fully appreciate the craftsmanship. After all, it looks pretty simple in “Billy Bathgate.” However, if the movies teach us anything about the ins and outs of the criminal underworld, then fitting a doomed gangster with concrete shoes is obviously far from the simple undertaking. First, you have to make sure you have the right proportions in your concrete mixture and then you have to convince the intended victim to keep still for a few hours while it hardens around his or her feet. Even at gunpoint, that requires some serious conversational talent.
We’ve all seen concrete in action. Someone drives up in a truck, pours the gritty, wet concrete into the desired area and workers shape and smooth it into place. After it dries, you essentially have a custom-sized slab of rock — only without having to cut blocks of stone out of the Earth. The technique is nothing new. The ancient Egyptians used a lime and gypsum mixture very similar to modern concrete as early as 3000 B.C., and opus caementicium was used throughout the Roman Republic.
Making concrete essentially resembles the common children’s pastime of making mud pies in which mud is poured into a pan and allowed to dry into solid dirt. Of course, no one ever built a skyscraper out of mud bricks or sealed a mafia informer’s feet in a slab of Georgia red clay. What is it that makes concrete special, and how do we turn to sand and water into something as solid and immobile as a concrete dam?
In this article, we’ll take a look at the recipe for modern concrete and the steps that go into paving our world.