Selecting the Best Insulation for Steel Frame Walls

Steel framed buildings are strong, stable and able to carry enormous loads. They also have very special needs when it comes to insulation. The wrong insulation can mean not only higher energy costs for the building, but also the potential for mold and moisture problems later on.

Using the right insulation, however, can help create the ideal tight building envelope you’re trying to achieve, while still letting the building breathe.

How Insulation Works in Steel Frame Buildings



Steel may be a strong, durable framing material, but it’s also a thermal conductor. When not properly insulated, steel allows heat - and associated energy - to travel through the frame. This makes steel buildings particularly susceptible to high energy costs, as well as cold spots and difficulty maintaining temperatures.

With more building owners demanding energy efficiency in their designs, the builder becomes the one who needs to address the issue. 

Insulating the frame—and particularly over the frame as well as between the joints—stops thermal transfer. This makes the building more comfortable and energy efficient for the occupants.

Why the Wrong Insulation Can Hurt

Achieving a tight building envelope has been the goal for builders for years. But creating a tight envelope in the wrong way can lead to more problems.

When a building is sealed too tightly, temperature differences between the interior and exterior can become too extreme. This leads to moisture build-up and, eventually, mold. A good way to prevent this issue is to use polythene sheeting on the interior.

Too many builders also find that they are faced with the decision of creating a tight envelope and then either dealing with water vapor or allowing thermal bridging to occur. However, if the right insulation is used, it can help with both issues.

So, while it’s important to insulate and create a tight envelope for clients, it’s also important to use the right insulation. Insulation that can breathe and allow for moisture management leads to better results on the project.

Kooltherm K12

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When framing a steel building, make sure to use an insulating framing board that is designed just for this purpose, like Kingspan’s Kooltherm K12. It was designed to be used between studs or as an insulating sheathing, helping to create a tight building envelope without moisture problems.

What It Is

Kooltherm K12 is a fiber-free, rigid framing board with composite foil facings on both sides. It has a thermoset phenolic insulation core that, combined with the low emissivity facings, is made specifically for use with steel frame construction.

It’s easy to handle and install and is designed to eliminate issues that are inherent with steel buildings.


While general insulation of steel buildings can help solve some issues, a product like Kooltherm K12 is needed to get the best performance possible. This framing board can be used not only between the studs but also as a continuous wall sheathing, which prevents thermal transfer through the steel.

It’s unaffected by air infiltration and is resistant to water vapor, so there won’t be problems with condensation over time. The R-value at 2-inches thick is R-16, which gives buildings superior insulation right at the area it needs it most, helping to keep the client’s operating costs low.

In addition to offering superior insulation for steel buildings, Kooltherm K12 is also Class 0 fire rated and has negligible smoke obscuration. Use it on new builds or on restoration projects to provide steel buildings with the performance, comfort and energy efficiency necessary in today’s building culture.

Get the Best Insulation for Steel Frame Buildings

Steel frame buildings offer strength and longevity that timber buildings can’t compare with. They also have special requirements to ensure that the steel doesn’t become a thermal bridge.

While most insulation does help prevent this issue, it’s the right insulation that prevents not only thermal bridging but also condensation, air filtration and fire safety.

Make sure that you choose the right insulation for your steel frame buildings, and use Kooltherm K12 each time to address any possible issues.

Kingspan Insulation North America

Head Office & Sales Office – North America

Kingspan Insulation LLC

2100 Riveredge Parkway, Suite 175

Atlanta, Georgia



Call: +1(800) 241 4402