A picture of a thermometer showing almost 100 degrees Fahrenheit, With an image of grass and sun, indicating very hot Florida weather.

Installing the right type of attic insulation is crucial, especially for homeowners living in hot and humid climates like Florida. If you’re a Florida resident, then you’re probably aware of the role proper attic insulation plays in keeping your house warm during winter and cool during summer.

So what are some of the best types of attic insulation for the Sunshine State? 

If you’re living in Florida and are unsure about which type of insulation to install in your attic, this article will take a deeper look at the common types of attic insulation in the state and discuss their main features, pros, and cons.

So, read on to learn more!

What Is the Best Type of Attic Insulation for Florida?

The best type of attic insulation for the hot, humid Florida climate is spray foam. Closed-cell spray foam has an impressive R-value in the range of six to seven per inch. Other adequate attic insulation types for Florida include blown-in fiberglass, blown-in cellulose, and fiberglass batt.

Best Type of Attic Insulation for Hot, Humid Climates

Most of Florida’s climate is subtropical, featuring brief, mild winters. Southern Florida boasts a tropical climate with average winter temperatures reaching 68 degrees Fahrenheit (20 degrees Celsius). 

Spring and summer in the Sunshine State are marked by hot, humid weather. In addition, Florida experiences hurricane activity in summer and early Autumn. Despite being nicknamed “The Sunshine State,” Florida is one of the wettest states in the country. 

Due to Florida’s hot, humid, and moist environment, the best attic insulation should be durable and ideally, completely seal the attic to keep out hot air. Some attic insulation also improves roof strength, adding extra protection during hurricane season. Finally, the best insulation for Florida’s climate should not absorb moisture.

Types of Attic Insulation for Florida

There are many types of attic insulation suitable for Florida weather. In this section, we’ll go over four different kinds, including spray foam, blown-in fiberglass, blown-in cellulose, and fiberglass batt.

Spray Foam Insulation

Spray foam is well-known for its exemplary performance when it comes to attic insulation. When properly installed by certified experts, spray foam insulation fills all the spaces in your attic, making it an effective air barrier. 

A picture of an open attic ceiling with spray foam sprayed to the underside, showing energy efficiency and a tight air seal.
The underside of an attic is sprayed with spray foam insulation. You can see how good it is at getting into all the tight spaces and expanding for a really good air seal.

Closed-Cell Spray Foam Insulation

This type of spray foam is characterized by closed, high-density cells that help seal the attic completely, allowing the system to act as a vapor and air barrier. In order to work, the cells are filled with gas that allows them to expand fully, thereby creating a full seal. 

Closed-cell spray foam insulation comes with several benefits, one of them being a high R-value rating of around R6-R7 per inch. Its R-value is higher than open-cell spray foam and other insulating materials, making the closed-cell spray foam one of the most reliable insulators in the market. 

The closed-cell spray foam is completely moisture impermeable, meaning it won’t absorb any moisture. While this is a huge advantage, it also means you’ll need to be on the lookout for potential leaks and roof damages as the material will conceal leaks. 

You can also count on closed-cell spray foam to improve the strength of your roof once it completely cures as it becomes dense, making it ideal for harsh weather conditions and storms.

Perhaps the greatest disadvantage of closed-cell spray foam is its high cost. This type of insulation is costlier than most other types of insulations. Installers also need to be very careful when spraying over wires and pipes as closed-cell spray foam hardens after curing, making it hard to retrieve covered items. 

Open-Cell Spray Foam 

Although not as dense as its closed counterpart, open-cell insulation still does a great job as an attic insulator. 

The cells are filled with air, allowing them to expand to a sponge-like system that seals air and acts as a sound barrier.  

While open-cell spray foam has significantly lower R-value than closed-cell spray foam, you can still count on it to regulate your home’s internal temperature. Open-cell spray foam is a lot more affordable than closed-cell foam, making it a popular option among homeowners.

Note: open-cell spray foam will allow moisture to pass, meaning a leakage in your roof will likely pass through the foam. 

Blown-In Fiberglass Insulation 

Blown-in fiberglass is a type of loose-fill insulation that’s efficient when used to insulate attics in hot and humid climates like Florida. The insulation boasts a fairly commendable R-value of R-2.5 per inch and is relatively cheap compared to spray foam insulation. 

With blown-in fiberglass, you can expect to fill tight voids around pipes, wiring, or areas with irregular framing, making it an ideal solution for those extra hot Florida summer afternoons. 

Blown-in fiberglass might sound different from batts, but the two methods use the same material, meaning the only difference lies in the installation method. Generally, however, a blown-in fiberglass installation is more thorough and effective compared to batt installation. 

A picture of a man in an attic spraying in chunks of cellulose blown-in insulation for energy efficiency.
Blown in fiberglass or cellulose covers the entire attic floor like a thick blanket, creating the insulating layer and protecting your conditioned interior space from the hot attic. In Florida, attic temperatures can get as high as 150-180 degrees Fahrenheit, which means your HVAC system has to fight very hard to keep your home cool.

Blown-In Cellulose

Unlike fiberglass made from tiny recycled pieces of glass, sand, and other materials, blown-in cellulose is made from fine pieces of shredded newspaper. The ground-up newspapers are treated with boric acid for fire resistance and insect control. 

Although blown-in cellulose isn’t as effective as spray foam insulation, it’s still a lot better than batts. Another advantage of blown-in cellulose is installing it as a DIY project after buying it in bags. Most local stores will allow you to rent or even use an insulation blower free of charge.

Be warned, though, that the chemical treatment in most blown-in cellulose insulation isn’t sufficient enough to prevent rodent and pest activity. 

Cellulose is good at absorbing and retaining moisture, meaning it can lead to mildew, mold, and even potential rotting. As a result, vapor barriers must be applied over the installation to help in the fight against moisture and rot. 

Fiberglass Batts 

Fiberglass batts are arguably the cheapest and least effective insulation compared to other methods. Unsurprisingly, they’re also among the most commonly used in homes, mostly due to their affordability. 

Despite not being 100% impervious to water, fiberglass batts are fairly good at resisting moisture, meaning you won’t be fully exposed to the risk of mold and mildew. 

Another advantage of dealing with fiberglass batts is their ease of installation. You don’t have to be experienced in insulating attics or walls to set up your batch of fiberglass batts. These batts are easy to unfurl and carry, allowing you to cover an extensive amount of space with relative ease. 

A picture of pink fiberglass batts/sheets installed between studs in an open wall vertically.
We’ve all seen this stuff before – the giant pink rolls of fiberglass batts that install between the studs when the walls are open.

Best Overall Attic Insulation for Florida

The best overall attic insulation for Florida is hands down spray foam insulation. With spray foam insulation, you get the ultimate insulation that’ll help regulate internal temperatures inside your home. 

Spray foam works by creating a thermal envelope, ensuring your house retains heat during winter and cools effectively during the summer. You’ll also appreciate that spray foam, more specifically closed-cell foam, helps keep moisture, mildew, and mold out of your attic. But you’ll need to be more careful with open-cell as it absorbs water. 

And while some people will swear by closed-cell spray foam, you can still settle for open-cell spray foam and get desired results. Open-cell foam is a lot cheaper than closed-cell foam, which makes it suitable for residential properties. 

When dealing with spray foam insulation, it’s highly advisable to outsource to experienced professionals who know the ins and outs of attic insulation. The installation process is fairly long and messy, but the cost will be worth the while once you start enjoying benefits like reduced energy costs and increased comfort. 

Blow-in fiberglass is also an effective way to cover the tight spaces in your attic, allowing for improved insulation. This method is a lot cheaper than spray foam insulation and works well if you’re looking to insulate on a budget.

You can also opt for fiberglass batts if you’re operating on a budget and want to install on your own. Be warned, though, that you won’t get as good performance with fiberglass batts as you would with either blown-in or spray foam insulation. 

Wrapping Up

Although the best type of attic insulation largely depends on personal preferences and budget, one can’t rule out the effectiveness of spray foam insulation, especially in a hot and humid state like Florida.

And while spray foam is undoubtedly the top insulation product, its high cost makes it less desirable for homeowners looking to insulate their attics on a budget. 

Cheaper alternatives include blown-in fiberglass and blown-in cellulose insulation, which, although not as effective as spray foam insulation, can still get the job done. 



  1. Thank you for the valuable information shared here. I am curious, could i please reference some of this to the new employees we are taking on this month? thanks again.

  2. Thanks for this valuable information. I’ve always told my partner Brett we need to keep investing more into spray foam insulation i think he finally agreed lol. Its a lot more efficient to use too.

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