Comparing Mineral Wool and Fiberglass Insulation: A Guide to Selecting the Suitable One for Your Construction Task

In the realm of home insulation, two popular contenders are mineral wool and fibreglass. Each offers distinct advantages and trade-offs in terms of composition, ease of use, thermal performance, lifespan, durability, fire resistance, soundproofing, price, and eco-friendliness.

Mineral wool, often referred to as stone wool, is made from natural stone fibers such as basalt or diabase, or recycled steel slag. Approximately 90% of its composition is recycled content, bound with resins and oils [1][5]. On the other hand, fibreglass is crafted from fine glass fibers spun into mats or batts [3][5].

When it comes to ease of use, fibreglass takes the lead. It is lightweight and easier to handle and install, making it a popular choice for DIY projects [3][5]. However, mineral wool, due to its higher density, is denser and stiffer, which can make it harder to cut and fit, particularly for beginners [3][5].

In terms of thermal performance, mineral wool boasts higher R-values per inch (typically R-4.0 to R-4.2), providing better insulation than fibreglass batts (R-11 to R-13) [1][3]. Fibreglass's performance, however, relies heavily on a good fit [1][3].

Mineral wool's durability is impressive, with excellent resistance to deformation. However, it can be prone to water absorption, which can reduce its effectiveness [5]. Fibreglass, while less durable, is vulnerable to compression and sagging over time, losing its effectiveness if compressed or moist [3].

Fire resistance is another area where mineral wool shines. Its volcanic rock base offers excellent fire resistance, making it noncombustible and capable of withstanding very high temperatures [1][2][5]. Fibreglass, while non-combustible, is less fireproof compared to mineral wool [3][5].

Mineral wool's superior sound absorption and noise reduction properties make it a popular choice for soundproofing applications [1][2][5]. Fibreglass provides some soundproofing but is generally less effective than mineral wool [3].

Price-wise, mineral wool is about 10% more expensive than fibreglass, considered a higher-end option due to its advantages [1][3]. Fibreglass, however, is more cost-effective, with a lower initial cost suitable for budget-conscious projects [1][3].

From an eco-friendliness perspective, mineral wool typically contains high recycled content (around 90%), but its manufacturing process is energy-intensive due to the melting of rock at high temperatures [1][5]. Fibreglass is made from recycled glass but has less recycled content overall, with a manufacturing process that consumes less energy than mineral wool [3][5].

For residential projects requiring high performance, mineral wool is a suitable choice due to its superior thermal performance, durability, fire resistance, and soundproofing [6]. Fibreglass, on the other hand, is the more affordable option, making it a popular choice for DIY projects [7].

In conclusion, mineral wool offers better thermal performance, durability, fire resistance, and soundproofing, with a higher price and more challenging installation. Fibreglass is cheaper, easier to install for homeowners, but has lower thermal efficiency and durability. Mineral wool is more eco-friendly from a recycled content perspective but has a more energy-intensive manufacturing process. Fibreglass is less expensive upfront but may require more frequent replacement or repair.

References:

[1] Building Green [2] Insulation Institute [3] Green Matters [4] Energy Sage [5] This Old House [6] The Guardian [7] Home Stratosphere

Comparing Mineral Wool and Fiberglass Insulation: A Guide to Selecting the Suitable One for Your Construction Task