Rigid Foam Insulation under Metal Roof: Which Is the Best Roof Insulation?

Many homeowners are exploring various insulation methods, including installing rigid foam insulation under metal roofs for enhanced performance. Foam board insulation is one of the top choices, recognized for its effective insulation properties and overall efficiency.

You probably think that the rigid form will make it difficult to install, but unless you do it yourself, you leave it to the pro to do the arrangement. Combining a sturdy metal roof and the right insulation can affect your house.

This approach not only enhances the aesthetic appeal of your home but also optimizes energy usage and management. Understanding the different types of insulation, such as spray foam and fiberglass insulation, can help you make a more informed decision.

Metal Roof and Proper Insulation

So, what’s the deal with a metal roof and proper insulation? You see, the popularity of metal roofs has increased lately. The metal roof is beautiful, and it has its aesthetic appeal. It’s also durable, so it can last longer than other roofing types, such as asphalt shingles.

Read also: Applying Burnished Slate Metal Roof

rigid foam insulation under metal roof

Combining it with insulation will boost energy efficiency, affecting your monthly bills and comfort.

Most roofing structures need to be insulated, regardless of the type or material. With insulation, you can improve energy conservation and reduce noise pollution. Want to make your house cozy, quiet, and warm? Then insulate your roof.  

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Can You Put Insulation under a Metal Roof?

Definitely yes. Even with the existing roof, you can install the insulation properly. This is one of the reasons why you need to hire a professional service. Roofing is a complex matter that needs professional care.

Not everyone can do it. And it’s certainly not the type of DIY project that you can do on your own. Want to get the best result? Hire a professional and certified expert to get the work done.

What Is the Best Insulation to Use Under Metal Roof?

You can use rigid foam insulation under a metal roof, but other options are available.

  • Fiberglass Batts

The material is similar to the one used in glassware. This type of insulation is cheap and easy. It’s the cheapest option for roof insulation. The material is also versatile and flexible. Feel free to cut it the way you want it to. Not only can you place it under the roof panels, but you can install it on the existing surface of the roof.

However, one downside is that some materials, like fiberglass insulation, are not entirely safe without proper handling due to microscopic glass fibers that irritate eyes, lungs, and skin. Hiring professionals with the necessary protective gear and expertise is advisable to safely install these materials.

The price depends on the R-value. If it has an R-value of 11, the cost may range from $0.12 to around $0.16 a square foot. If it has 38 R-value, it may range between $0.55 and $0.60 a square foot.

  • Rigid Board

This type is handy for thermal resistance, especially for walls, roofs, and foundations. This insulation is available in panels or sheets of various sizes. The panel or sheet is made from polyurethane or polystyrene.

This one can provide maximum thermal resistance when it’s installed properly. It means that you should seal the joints and fit the sheets tightly together. It’s also handy in reducing air leakage.

The only downside is that it must be installed properly. Otherwise, it can be easily damaged by the UV rays. If you don’t fit the sheets tightly, it still results in air filtration or leakage. In terms of price, the price may range from $3.95 to around $7.20. it depends on the quality.

  • Spray Foam

This insulation type must be mixed with water, and it needs a special machine for the application. It’s likable because it is one of the most effective choices for the metal roof, and it’s also easy to work with – for those who are experienced with this method.

With it, you don’t have to re-proof to install the insulation. It’s also the best option for areas with odd or awkward shapes. It’s also effective enough to prevent insect or rodent infestation and condensation buildup.

The only downside is the application. As mentioned before, this can only be done by a professional, considering the tools and equipment. This insulation costs between $1 and $1.50 a board foot for the closed-cell spray foam. If you go with the open cell spray foam, it’s from $0.44 to $0.65 a board foot.

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It’s up to you to choose which insulation for your metal roof. If you are adamant about the rigid foam insulation under a metal roof, that’s fine, but you should know that you have different options.

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RoofLast is an experienced author and roofing expert. With years of practical experience in the field authored several informative articles on various aspects of roofing, including installation, maintenance, and repair