The Five Different Types of Fireproof Insulation Materials

Unless you want to add an extra zero or two onto your utility bills, insulating your home is a must. By sealing the areas where air escapes in crawl spaces, basements, and attics, insulation can reduce heat transfer and drastically slash the amount you spend on heating and cooling your home. And when we say drastic, we mean it – according to Energy Star, most homeowners can save an average of 15% on heating and cooling costs (or an average of 11% on total energy costs) simply by using appropriate insulation.

Yet despite the obvious benefits, very few people are working it to their advantage. Only 10% of single-family homes in the US have sufficient insulation, meaning most of us are paying far more for our utilities than we really need to. If you’ve decided to make 2021 the year you finally cut those energy bills and bring your drafty home under control, then firstly, congratulations on a wise choice. Secondly, there are a few things you need to know about the various options available before going any further.

Regardless of where you buy your insulation from, who you choose to install it, and which brand you pick, make sure it’s fireproof. While the primary purpose of insulation is to provide a carrier against heat transfer, choosing a fireproof option safeguards your home against catastrophe. As well as helping slow the progression of large fires, it can stop minor fires caused by electrical circuits in their tracks. Fireproof insulation materials come in five primary varieties: fiberglass, mineral wool, foam, reflective insulation, and fibrous mats. Here’s what you need to know about each of the five most common varieties.

Table of Contents show

1. Fibrous Mats

As 5starinsulation.com notes, fibrous mats are one of the most common types of insulation used in the home. They consist of a number of different types of materials that are collectively referred to as asbestos. We all know the name asbestos, and most of us would think it’s the last thing you should willingly introduce into your home.

However, despite the associated health risks, the fact remains that there are very few alternatives to it. Replacements such as low-melting-temperature polymers and aluminum oxides are available, but they lack the efficacy and affordability of asbestos. As such, it remains a common material that’s used in a huge range of applications, from clutches and roof tiles to household insulation. Risks aside, asbestos is an incredibly strong, durable material that offers both heat and chemical resistance.

As it doesn’t conduct electricity, it can help reduce the risk of electrical circuits sparking a fire. While most insulation is rated ‘fireproof’, it’s worth noting that in general terms, this simply means it resists fire. Exposed to very high temperatures, most forms of insulation are combustible. In this regard, asbestos stands up well to scrutiny. Although it’s not entirely fireproof, asbestos insulation can handle temperatures in excess of 3,000 degrees, making it one of the most effective forms of protection available.

2. Fiberglass

Fiberglass (or glass wool, as it’s sometimes referred to) is now the most common form of insulation used in both private and commercial buildings. It’s made by weaving very fine strands of glass into a material before applying specially designed resins as a bonding agent. When used as an insulating material, it’s either blown into the required area or packed into slabs or rolls for easy installation. In addition to being moisture resistant, fiberglass is also non-combustible, with R-values ranging from R-2.9 to R-3.8 per inch.

Thanks to its affordability, wide availability, and efficacy, fiberglass makes an excellent option for insulation. It does, however, come with a flipside. Due to the way in which it’s made, extreme care needs to be taken during handling. If handled roughly and without the proper safety equipment being worn, tiny slivers of the material may break away, causing damage to the eyes, skin, and even lungs if inhaled. Like other insulation material, fiberglass isn’t entirely fireproof, but it can routinely withstand temperatures of up to 1,220 degrees.

3. Mineral Wool

As thermaxxjackets.com notes, mineral wool actually refers to several different types of insulation. Sometimes, it’s used to refer to glass wool. Other times, it refers to rock wool, which is a form of insulation made from basalt. In most instances, however, it refers to slag wool. This is particularly the case in the US, where slag wool is one of the most common and popular forms of insulation. Mineral wool has an R-value ranging from R-2.8 to R-3.5, making it an effective form of insulation. Although it’s unable to withstand the same high heat as certain other options, it’s not combustible. It’s generally used in combination with other forms of insulation to improves its fire resistance properties.

4. Reflective Insulation

Designed, as its name suggests, to reflect heat, reflective insulation is a popular and effective form of insulation. It’s made by bonding reflective material (usually aluminum, but other materials are sometimes used) with plastic film, cardboard or kraft paper. It’s typically used between floor studs, roof rafters, and wall joists in roof insulation, but may also be used as a surfacing agent on insulation boards to improve performance and heat transfer. It’s usually used in combination with other forms of insulation material rather than alone, with its overall effectiveness relying on variables such as weather condition and placement.

5. Foam

As Hunker explains, cellulose is made from recycled newspaper. Newspaper may not sound like the best fireproof material in the world, but thanks to the addition of chemical flame retardants, cellulose offers flame-resistance up to 300 degrees F. It’s not, however, entirely fireproof – once temperatures exceed 300 degrees F, the fire-resistant chemicals may ignite, thus costing the insulation its fire-retardant properties. Foam cellulose offers greater resistance to heat, but may still combust at very high temperatures.

As certain forms of cellulose foam insulation have been known to produce toxic gasses linked to migraines, eye irritation, respiratory problems, and even liver and reproductive damage (polyisocyanurate and polyurethane foam being two of the worst offenders), rigid foam insulation that utilizes expanded polystyrene is typically preferred. The options here are numerous, with two of the most popular choices being Icynene, which is an open-cell foam that combines carbon dioxide and water, and Air Krete, a non-toxic solution made by extracting magnesium oxide from seawater.