Which Type of Insulation Is Best For Metal Buildings?

Many people opt for metal buildings due to their durability, versatility, and ease of construction. The problem with this type of building is that their energy efficiency and internal climate control rely heavily on proper insulation. When choosing the best insulation for your metal building, there are several factors to be considered, such as climate, budget, moisture control and adequate installation method. In this post, we will discuss different insulation options to help you choose the best materials, products and application method.

Rigid Foam Board Insulation

Rigid foam board is a solid choice for metal buildings, with high R-values and relatively thin layers as main characteristics. It is a perfect choice for areas with limited space, like the walls or roofs of smaller metal buildings. Foam boards are usually made from polystyrene (EPS or XPS) or polyurethane, both of which resist moisture and provide good thermal resistance. The main advantages of this material are moisture resistance and easy installation.

Also, it works very well with other insulation types. Disadvantages of rigid foam boards are higher upfront cost and lower flexibility - they are pretty hard to fit around irregular shapes. Our advice is to use them for buildings with extreme weather conditions because they provide both insulation and a moisture barrier.

Reflective Foil Insulation

Reflective or radiant barrier insulation works differently than traditional materials like fiberglass or foam. This type of insulation reflects radiant heat away from the building instead of absorbing it, making it ideal for hot climates where keeping the interior cool is a priority. If installed properly, they reflect up to 97% of radiant heat. The general advice is to place these barriers under the roof or walls. They are lightweight and easy to install, and you can combine them with other insulation material, if necessary.

Keep in mind that reflective foil insulation is not effective in cold climates and it does not add much R-value itself. It should be your first choice if you live in hot, sunny regions where heat reflection is more important than thermal resistance.

Loose-Fill Insulation

Loose-fill insulation is a great option for insulating hard-to-reach areas such as ceilings and irregularly shaped spaces. Loose-fill insulation is made from small particles of fiber, foam or other materials and the interesting part is that it can be blown into wall cavities or attics. Other materials that can be used for loose-filing are cellulose, fiberglass or mineral wool.

The great advantage of loose-fill insulation is that it provides good soundproofing and can be easily added to existing insulation layers. Use it for retrofit projects where there are gaps or cavities to fill, but don’t do it yourself - it requires specialized equipment for installation. Do the inspection of it regularly, because it can settle over time, which leads to reducing its effectiveness.

Mineral Wool Insulation

Mineral wool (or rock wool) is another option for insulating metal buildings, especially when fire resistance is a priority. It is made from molten rock or industrial waste that’s spun into fibers. You should choose this insulating material if safety is a top concern - it is denser and more fire-resistant than fiberglass or foam. Alos, it provides good soundproofing and it is resistant to moisture and mold.

It is recommended for warehouses or storage facilities with flammable materials.Don’t be surprised with its price - it is more expensive than fiberglass or loose-fill, and it is heavier and more challenging to install.

Cotton or Denim Insulation

For environmentally conscious builders, cotton insulation, also known as denim insulation, is a sustainable and eco-friendly option. This type of insulation provides similar thermal and soundproofing qualities to fiberglass, plus it is non-toxic and made from recycled cotton or denim scraps. The drawbacks of this material are higher cost and moisture absorption, which can lead to mold growth.

Factors to Consider When Choosing Insulation for Metal Buildings

Now, when you know the characteristics of different insulation materials, it is time to make the final decision. Which material will suit your needs depends on several factors. Each building has its own unique requirements depending on its use, location, and structure. In hot climates, materials that reflect heat may be the best, while in cold climates heat loss can be prevented with spray foam or fiberglass.

Metal buildings are prone to condensation, so choose closed-cell spray foam, rigid foam or reflective foil insulation for the superior moisture resistance. In areas with high humidity, avoid insulation types that absorb water, like fiberglass or cotton, unless paired with a moisture barrier like Prodex.

If your budget plays a crucial role, choose more affordable options such as fiberglass and loose-fill. Also, reflective insulation and foam boards may provide good value in the long run. For DIY projects, fiberglass and reflective foil are the easiest to install. Spray foam and loose-fill typically require professional installation, increasing the cost.

Combining Insulation Types for Optimal Results

Often, the best insulation strategy for a metal building involves combining two or more types of insulation to address different needs. Our recommendation is to combine reflective foil with rigid foam boards for reducing radiant heat while providing a higher R-value. On the other hand, you can use spray foam on the roof and loose-fill in walls if you want both energy efficiency and moisture control. Get informed about all insulating materials, products and installation techniques before making the final decision. If you are confused and do not know what will work best for you, ask professionals for help.