Steel Building Insulation: Best Practices & Materials

Are you considering a steel building? Do you want to make sure it stands the test of time and protects the health of those using it? Then, you should consider your options for steel building insulation.

Why Insulate Your Metal Building?

Steel, like all construction metals, is a great conductor of heat.

This means that a simple metal exterior will transfer a lot of heat when the weather is hot and let it all out when it turns cold. You also have the issue of condensation, which can lead to problems like rust and mold.

Getting steel building insulation solves all of these problems and provides some bonus benefits too. A more regular temperature inside your metal building makes it a more habitable space – important for offices or stores –plus it reduces your energy bills, and who doesn’t love saving a bit of money all year round?!

How Does Insulation Work for a Metal Building?

Insulation helps regulate heat transfer, so your carport or steel building is cooler in summer and warmer in winter.

It also prevents condensation and all the issues that come with it and helps reduce the amount of noise you can hear outside the building (great if you have a steel-built workshop or commercial garage).

When choosing the best insulation for your steel building, there are many types to consider. Costs vary, and so do the benefits.

Pay attention to R values as these tell you exactly how effective each insulation type is. A higher R-value means the material has a higher resistance to heat and better insulates your metal building.

What Materials Should You Use to Insulate Your Steel Building?

As we said, there are plenty of choices when it comes to steel building insulation materials. Here are the most popular ones:


Loose fibers or pellets are blown into wall cavities reaching and insulating every nook and cranny. There are different pellets available, but they all do a similarly great job of insulating your metal building.

A contractor best does this work as specialist equipment is needed, and as a result, this is one of the costlier insulation methods.

Spray Foam

Similar to loose-fill, spray foam is inserted into the wall cavity in liquid form but then quickly expands and hardens to create a very effective barrier against heat and air transfer.

It’s also more expensive than other insulation types because of the expertise needed to apply it properly. If your budget allows for it, though, you can’t go far wrong with spray foam.


Made of processed rock wool or fiberglass, batt insulation (sometimes called blanket) offers outstanding value for money.

If using this insulation for a steel building, you should look for batts with a radiant coating, which helps increase their thermal resistance (remember the R-value?) without impacting the price in a big way.

Rigid Board

Rigid boards are highly effective at reducing heat and noise transfer. They’re made of fiberglass, polystyrene, or polyurethane and easy to cut and fit most spaces.

You can install this yourself in an existing building if the cavity allows for it. If you’re planning to install once your metal building is complete, let your building contractor know so they can make allowances for it.


One of the most popular steel building insulation materials, fiberglass is cheap and effective but can attract bugs and absorb moisture.

Make sure your fiberglass insulation is certified for its effectiveness in metal buildings and comes with a vapor barrier to reduce moisture.

Insulating your steel building

Depending on your choice of insulation material, you may want to install it yourself. If so, choose a calm day to do the work, focus on one side at a time, and ensure that you pay close attention to seams and joints.

Want to learn more about steel buildings? Read about the advantages of using a metal building for your business or see how easy it is to build a protective metal workshop.

Call California All Steel today for more information and guidance on the best way to insulate a steel building.

Got questions?


Get in Touch for a Free Quote