Smart Building Choice for Fire Endurance

Insulated Concrete Blocks – The Smart Building Choice

One of the most devastating forces of nature is fire, whether it’s a naturally occurring wildfire or otherwise. Fires can quickly destroy homes and businesses, sweeping through an area far more quickly than many realize. When it comes to construction of a new building it is important to consider fire resistance. With advances in technology there are more options than ever when it comes to materials but one in particular, insulated concrete block systems (Bautex Block), come out on top.

What is a Four Hour Fire Rating?
Before getting into why insulated concrete blocks are one of the smartest choices for new buildings it’s important to understand what fire ratings are as well as how they are determined.

As the name suggests, the Four Hour Fire rating is determined by the buildings abilities at resisting fire for up to four hours. There are different ratings but with insulated concrete block construction installed properly you can expect roughly 4 hours before the structure fails. These ratings were originally created back in 1905 and has since been updated to include how thickness of non-combustible materials can impact real fire rating.

Insulated concrete blocks typically pass a 4 hour test, both in terms of protecting the inside from fire as well as confining fire. Concrete is a favored material since it isn’t only strong and naturally non-combustible, but also because it won’t leach chemicals in the event of a fire. This can be a serious issue with other building material, even if they have an impressive resistance.

How is Fire Resistance Tested?
Materials being tested for fire resistance are done very much as you’d assume, which is exposing the material against real fire to determine how long it would remain structurally sound. Most fire ratings are done in hour increments, with 4 hours being excellent.

While testing against a fire is obvious, another part of the test not many realize is that the material is also exposed to a firehose stream to replicate real life events. The fire hose stream test only lasts a few moments but can greatly affect the building’s fire resistance. This is due to the sudden impact of a powerful stream of water and the difference in temperature between fire and cold water. Even if a material is doing well against the fire itself, it may crumble and fail when exposed to the hose.

Why are Insulated Concrete Blocks Ideal?
Concrete is one of strongest and least combustible building materials that can be used. When it comes to fire endurance there are two factors to consider – fire resistance of the material and integrity of the structure. Fire resistance is the ability to endure a fire or protect the inside of the building from a fire. It can also be applied to the building’s ability to contain a fire that starts inside. Buildings constructed with exterior concrete walls excel in both resisting and containing fire.

As for structural integrity concrete once again outperforms many other materials. Integrity of the structure is based on the overall stability and ability to remain erect in the event of a fire. Even if the fire isn’t within the building, the extreme heat can cause stress to the building and damage that result in collapse. Concrete does a good job of remaining erect in the event of the fire, which makes is safer for firefighters to work around and for those trapped inside to more safely escape.

Cast-in-place, reinforced concrete offers the most fire resistance but insulated concrete blocks come in at a close second. This more modern take on concrete is more versatile, more economical, and allows for a more energy-efficient building – all without sacrificing fire resistance.

The fire resistance of insulated concrete blocks does vary from manufacturer to manufacturer as it largely comes down to not the concrete, but the core or filler material used. There are various factors that can affect fire rating, including:

  • Thickness of the concrete block
  • Core filler material
  • Any aggregate blends
  • Exterior and/or interior wall finishings used

Smart BuildingInsulated concrete blocks with thicker concrete walls, low-combustion filler materials, and a wall finish or cladding that is also designed to resist fire is the best route to go.

One common issue with some insulated concrete blocks is that many manufacturers choose a foam filler. Foam provides excellent insulation but the choice of foam can seriously impact the fire-fighting ability of the wall as foam can be highly combustible. To get a higher fire rating insulated concrete block wall system companies, like Bautex, have switch to EPS or expanded polystyrene. This foam is offers lightweight, closed-cell insulation with enough rigidness to help with stability without significantly affecting fire resistance.

Insulated concrete block construction is one of the best choices to go with when considering the fire endurance of a building. Not only is this style of wall easier and faster to put up, but it also offer more benefits than regular reinforced concrete walls. These amazing insulation not only helps keep fires at bay for longer, but also allows for more energy efficiency within the building on a daily basis.

For more about Bautex, see Build Your Home with Insulating Concrete Forms.

Author: Paul Brown
Paul received his Bachelor of Arts from the Plan II Honors Program at The University of Texas at Austin and his MBA from The Fuqua School of Business at Duke University, and received his LEED Green Associate credentials from the US Green Building Council. He now leads the team at Bautex Systems overseeing operations and strategic growth.