When building a house or commercial building, it is always best to soundproof the structure. One of the most popular soundproofing methods is using mineral wool, better known as rock wool insulation. It is a thermal insulator and a sound absorber made primarily from recycled material.
Mineral wool is good for soundproofing. This insulation is an excellent way of blocking unwanted noise because it has a fiber matrix that absorbs sound waves. In fact, mineral wool batts are denser than other insulation materials, making them superior in soundproofing.
This article focuses on the use of mineral wool as a soundproofing material, how it compares to more common materials and whether it’s worth it. Read on to learn everything you need to know about mineral wool.
Also read: Glasswool vs. Rockwool for Soundproofing & Acoustics
What Is Mineral Wool?
Mineral wool is a versatile type of insulation with a wide variety of applications. The insulation material is quite similar to fiberglass, but it is made from natural materials instead of glass. It is often referred to as rock wool.
There are 2 basic types of mineral wool insulation categorized by the materials they’re made from.
Slag Mineral Wool
Slag mineral wool is made from spinning slag, a waste product in the steel manufacturing industry. Some manufacturers also make it from a combination of slag, natural rock, and even glass. Typically, this insulation material contains up to 75% recycled material.
Rock Mineral Wool
This type of mineral wool is made from natural stone fibers like molten ballast or diabase. It is often sourced from volcanic rock and melted at temperatures above 3,000°F (1648.89°C). The molten rock is then spun into wool-like material and bound by oils and resins.
Both types of mineral wool are sold as loose-fill and in batts. You can use them in all home insulation applications, including ceilings, roofs, and floors.
Is Mineral Wool Good for SoundProofing?
Mineral wool is an excellent soundproofing material. Its high density and mineral composition make it not only good for thermal insulation but also for acoustic performance. The material also has an open fiber matrix that absorbs sound waves.
You can install mineral wool where you would typically install fiberglass and help with soundproofing. It is an excellent option for multifamily residences or families that live near train tracks or other noisy areas.
Uses of Mineral Wool
Mineral wool has many uses and can be used as insulation as well as soundproofing. Below are some examples of how mineral wool is used.
1. Thermal Insulation
Mineral wool has a wide range of uses in construction. Its main application in this industry is thermal insulation. Though the individual fibers are good conductors of heat, pressing them into rolls or sheets increases their ability to partition air. This turns them into excellent insulators.
As a result, mineral wool is often used in walls, ceilings, and floors during home construction to protect the rooms from the harsh temperature outside.
The second application of mineral wool is soundproofing. Like in heat insulation, pressing the fibers into rolls or sheets enables them to partition air. This also deters any sound from passing through, making mineral wool good soundproofing material.
3. Fire Proofing
As we’ve seen, mineral wool has incredible thermal insulation properties. In fact, tests show that mineral wool can withstand temperatures upwards of 1800 degrees Fahrenheit. It does not produce smoke or toxic gasses when exposed to high temperatures.
Although it is not immune to the effects of a severe fire, it’s still commonly used in buildings where passive fire protection is necessary.
Is Mineral Wool Durable?
Mineral wool is a very durable material. Its R-value (insulation value) remains unchanged for a long time. On the other hand, other standard insulation materials like fiberglass will decrease their insulation value over time.
This is primarily because of the constituent materials of mineral wool, including steel slag and rock. These materials are known to be naturally resistant to corrosion and degradation.
Mineral wool’s durability is also not limited to maintaining its thermal insulation properties. It also remains water-resistant, fire-resistant, mold-resistant, and mildew resistant for a long time.
The water resistance properties are especially important because, without them, mineral wool would absorb moisture from the humid air. This would eventually break the material down.
Is Mineral Wool Better Than Other Insulation Materials?
Mineral wool is better than most other insulation materials in the market. In fact, it is better at thermal insulation, soundproofing, and fireproofing than the most common insulation solutions. It is also more resilient and will retain its insulation value for a long time.
Unfortunately, while it’s popular in Canada and Europe, mineral wool is still not as common as other insulation materials in the United States.
Rockwool vs Fiberglass
Fiberglass is one of the most common insulation materials in the United States. Since it is a more established material, most people have relied on it in the past. However, people are learning about mineral wool and making the switch.
Of course, fiberglass will always have a place in the market because it is cheap, easy to install, and comes in various sizes. It also does a great job insulating, which is its primary purpose.
The only difference with mineral wool is that it does everything fiberglass can do, only better. With better acoustic properties, R-value maintenance, water resistance, and overall durability, it seems worth the extra investment.
Houses sometimes use a combination of both materials, with the cheaper fiberglass going in common areas, while mineral wool is used sparingly in areas that need stricter thermal control.
Disadvantages of Using Mineral Wool Insulation
While mineral wool is a well-rounded insulation solution, it does have its weak points. These include:
- Lower heat storage: The material has a lower heat storage capacity than natural insulation materials like wood wool, sheep’s wool, and cellulose flakes. This means that the room will heat up faster in summer because the material cannot hold the heat long enough.
- Irritation: Mineral wool can cause skin irritation in case of contact. It can also trigger allergies on inhalation. As a result, it is advised that you wear a mask and gloves when you work with it.
These are fairly small issues that most people would be able to look past, especially when they consider that the alternatives are not any better.
Mineral wool is an excellent soundproofing material. Its high density and material composition make it good for acoustic performance. In addition, it has an open fiber matrix that helps it absorb sound waves.
Compared to fiberglass, mineral wool is superior in thermal insulation, noise reduction, fire resistance, and R-value maintenance. The only disadvantage is that mineral wool is a bit more expensive.
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- ENERGY.GOV: Insulation materials
- Rockwool: Fire safety
- Energy Education: R-value
- Attainable Home: What is the R-Value of Rockwool Insulation? (With Chart)
- Quora: Is mineral wool good for soundproofing?
- Sound Service: soundproofing: Acoustic Mineral Wool (AMW) for Cavities
- Eurima: Mineral wool insulation
- Rise: What is Mineral Wool Insulation?
- Bob Villa: 7 Things to Know About Rockwool Insulation Before Installing It in Your Home
- Greenage: 10 Reasons to Use Rockwool Insulation in Your Home
- Family handyman: Why Choose Mineral Wool Insulation?
- Insulation-info.co.uk: Mineral wool: properties, advantages & price
- Home tips: Rock-Wool Insulation: What It Is and Where to Use It
- Retro foam of Michigan: What is Mineral Wool Insulation? What it’s Made of and How it Works
- The Soundproofing Store UK: What is the best soundproof acoustic insulation?