Rockwool/Roxul Safe’n’Sound vs. Fiberglass for Soundproofing Review

When it comes to soundproofing, acoustic insulation is very important. It is an integral component of walls, floors, and ceilings. Why? Because its job is to absorb sound waves or block them, essentially forming a sound barrier. 

This way, your house or any particular room in it, can be super quiet. However, you have to choose between Rockwool/Roxul Safe’n’Sound and Fiberglass. That’s not always an easy choice. Usually, it depends on many different factors, such as budget, desired density, and more. 

Today, we will explore both options in-depth so you can understand the similarities and differences. Once you have all the information, you can decide who wins the Rockwool vs. Fiberglass encounter in your book. 

Everything You Should Know About Rockwool/Roxul Safe’n’Sound for Soundproofing

What Is Rockwool/Roxul Safe’n’Sound Soundproofing?

Rockwool is made from rocks and it absorbs sound waves very well. It’s fire-resistant and it’s also known as Roxul because that’s the name of the manufacturer. 

Rockwool safe and sound is dense but porous and it absorbs vibrations. It also reduces the movement of cold or heat. It’s super durable, long-lasting, water-repellant, and resistant to mold buildup. If you want to learn more, click here.

Rockwool/Roxul Safe’n’Sound Acoustic Properties

When it comes to Roxul safe’n’sound, their products provide different acoustic properties. It depends on their density and thickness. Rockwool safe and sound have a density of 2.5 lb/ft³. 

It has a Sound Transmission Class of 45 on 16” for center wood studs; 52 with 24” for center steel studs; and 50 when it’s installed between floor joists. It also features a Noise Reduction Coefficient of 1.05 for 3-inch thickness, which is better for sound control. 

What Is Rockwool/Roxul Safe’n’Sound Made of?

Rockwool is made of mineral wool, which is what you get when you heat rocks to 3,000 °F. Under that kind of temperature, the rocks turn liquid. Then, air or steam is jetted into the liquidized rocks under high pressure and at high speed. This turns the liquid into fibers. After that, the fibers are compressed to make dense mats that are then cut into strips. Here’s a video if you want to see what the process looks like!

Uses For Rockwool/Roxul Safe’n’Sound 

Rockwool safe and sound can be used in walls, ceilings, floors, and attics. It can also be used in planes in vehicles because it reduces the movement of temperature and sound. 

Roxul Safe’n’Sound can also be sued in engine compartments, around pipes to reduce temperature loss, and in machinery rooms. It even has certain hydroponic applications. 

Is Rockwool/Roxul Safe’n’Sound Effective for Soundproofing?

Because it’s dense and porous, Rockwool is a great temperature and sound insulator. The thicker and denser the panels are, the more sound they will absorb, no matter the frequency. 

There are different densities available to address low, mid, and high frequencies. So, yes, it’s very effective for soundproofing. You just have to choose the right density for your needs. 

How Long Does Rockwool/Roxul Safe’n’Sound Last?

Rockwool safe and sound is incredibly long-lasting. It’s doesn’t absorb any moisture and it won’t shrink or become brittle. With a lifespan of 100 years, Roxul Safe’n’Sound will last as long as the building or home it’s in. 

Is Rockwool/Roxul Safe’n’Sound Safe?

Yes, Rockwool safe and sound is not dangerous. But, it can irritate the eyes and skin when you’re working with it. That’s why you should use eye protection, a dust mask, and gloves. Other than that, there aren’t risks associated with this material. 

Everything You Should Know About Fiberglass for Soundproofing

What Is Fiberglass?

Fiberglass is a kind of plastic, but it’s reinforced with glass fiber. It’s made of plastic wool and tiny glass shards are embedded in it. Usually, the plastic matrix is a thermoset polymer. Like vinyl ester, polyester resin, or epoxy. 

The fibers can be flattened into sheets, weaved into fabrics, or arranged in patterns. There are many different types of fiberglass, including 703 and 704. These are the most common when it comes to soundproofing and thermal insulation. If you want to learn more, click here

Fiberglass Acoustic Properties

The acoustic properties of fiberglass depend on its thermal characteristics, thickness, and presentation. Whether it’s batten, board, mat, or panels. On average, acoustic fiberglass features a density of 1.5 lb/ft³, 3 lb/ft³, or 6 lb/ft³. 

Its Noise Reduction Coefficient rates are between 0.65 at 1” thickness and 1.15 at 4” thickness. For better soundproofing results, it’s recommended to get a 6-inch thickness. 

What Is Fiberglass Made Of?

Similar to Rockwool, fiberglass is made of ordinary glass that’s exposed to extreme temperatures. Once the glass is liquidized, it’s compressed through tiny holes to make filaments. These filaments are super fine and can be long or short. They are packaged into several forms and are great for insulation. Here’s a video if you want to see what the process looks like!

Uses of Fiberglass

Fiberglass can be used to insulate homes, so it’s installed in walls, ceilings, and floors. It can control the movement of temperature and sound. It can also be used in cars and planes, pipes, and machinery. Fiberglass can even be used in space shuttle design!

Is Fiberglass Effective for Soundproofing?

Fiberglass is very effective at controlling both temperature and sound. The denser and thicker it is, the better it will be at soundproofing. As long as you choose the proper thickness for your soundproofing needs, you will be very happy with fiberglass insulation. 

How Long Does Fiberglass Last?

When fiberglass is installed inside walls, ceilings, or flows, it will last up to 80 years, maybe more. However, it will compress and slump over time, which is the main issue with battens and rolls of fiberglass. That can cause uninsulated pockets, so it’s something to keep in mind. 

Is Fiberglass Safe?

Just like Rockwool, fiberglass is not dangerous, but it can irritate the eyes, throat, nose, and skin. When handling it, you should wear protective gear, such as gloves, dust mask, eye protection, and keep your skin covered. 

It should be covered with an impermeable material while it’s unfinished to prevent particles from becoming airborne. These particles should not be inhaled by any means, so precaution is highly encouraged. 

Rockwool/Roxul Safe’n’Sound vs. Fiberglass: Which Is Best for Soundproofing?

Now that you understand both Rockwool and fiberglass a lot better, it’s time to decide which one you should choose. Rockwool vs. Fiberglass is not always an obvious choice. However, it helps when you pay attention to specific factors, such as: 

  • Size
  • Density
  • Noise reduction coefficient
  • Insulation
  • Heat resistance
  • Safety
  • Cost

Let’s discuss each of these factors separately and compare Roxul vs. Fiberglass in-depth. 

Rockwool vs. Fiberglass: Size

Rockwool common sizes are 16 inches by 48 inches and 24 inches and 48 inches. There are also larger sizes available. Roxul safe’n’sound boards can be up to 6 inches thick, while batts can be up to 7.5 inches thick. It all depends on the application. 

Fiberglass types 703 and 705 are the most common and they’re available in lengths of 24 to 121 inches, and widths of 45 to 49 inches. Usually, fiberglass 703 thickness ranges from ¾ to 4 inches, and ½ to 2 ½ inches for type 705.

Roxul vs. Fiberglass: Density

Density is a very important factor to consider depending on the application. Rockwool density is 2.4 lb/ft³ (38 kg/m³), while fiberglass type 703 has a 3.0 lb/ft³ (48 kg/m³) density, while type 705 has a 6.0 lb/ft³ (96 kg/m³) density. 

Rockwool vs. Fiberglass: Noise Reduction Coefficient

The NRC determines the average sound absorption of the material in question across different frequencies. When NCR is 0, it means the material can’t absorb mid frequencies. When NCR is 1, it means the acoustic surface area of the material is equivalent to its physical surface area. 

Rockwool safe and sound batt 3-inches thick has an NCR of 1.05 or 1.15 if the thickness is 6 inches. When it comes to fiberglass, insulation will depend on thickness and type of product. For example, 703 1-inch thick has an NCR of 0.70, while 4 inches provide an NCR of 1.15.

Roxul vs. Fiberglass: Insulation

R-value expresses insulation and it measures how a two-dimensional barrier can resist the flow of heat. The higher the R-value, the greater the insulation. Rockwool’s R-value is 3.0 to 3.3 per inch, while fiberglass’ R-value is 2.2 to 2.7 per inch. It will depend on the kind of product for each. 

Rockwool vs. Fiberglass: Heat Resistance

When it comes to heat resistance, Rockwool is a better choice. This material has a higher melting point, which is 1,800 °F or 1,000 °C. Plus, the material is non-combustible and it can contain a fire. Fiberglass types 703 and 705 have a melting point of 1,100 °F or 600 °C. 

Roxul vs. Fiberglass: Safety

Rockwool and fiberglass are both quite safe. The only major health risk is inhaling the fibers. Traditional Roxul safe’n’sound can be harsh to unhale, but HT Roxul safe’n’sound is one of the safest options. The fibers dissolve easily and are non-carcinogenic. 

Similarly, fiberglass is not dangerous and there’s no evidence of it being carcinogenic. It’s important to note that type 703’s fibers are more abrasive than those of HT Roxul safe’n’sound. So, it may cause a lot more irritation the more exposed you are to it. 

At the end of the day, it doesn’t matter what material you choose, you should never forget your protective gear. When you’re installing insulation, you must use dust masks, gloves, eye protection, and protective clothing. Make sure to have those things at hand.

Rockwool vs. Fiberglass: Cost

Last but not least, the cost is another important factor to consider. On average, Rockwool safe and sound costs $1.30 per square foot. However, the price may vary depending on density and thickness. The greater the thickness, the higher the price.

The cost of fiberglass will depend on the type of fiberglass you’re interested in. A type 703 board with FRK facing will cost around $85, with a total area of 48 square feet and 2-inch thickness. A type 705 board with the same specifications will cost around $125. 

Choosing Between Roxul and Fiberglass

Both Rockwool and Fiberglass are extremely effective at soundproofing. Roxul Safe’n’Sound is best used in panels and traps, while fiberglass will work best in ceiling and wall cavities. Rockwool safe and sound will also be best for damp locations because it won’t deteriorate like fiberglass. 

Rockwool and fiberglass can be easily cut, sized, and installed, but Rockwool is a lot more expensive. However, considering how much more durable and resistant it is, Rockwool will be worth the investment. Additionally, Rockwool offers noise reduction up to 10 decibels, while fiberglass ranges between 4 and 10 decibels.

Rockwool also has the upper hand when it comes to moisture resistance and it doesn’t attract mold like fiberglass. Both materials are similar in many ways, but Rockwool seems to be the best option overall. If you can afford it, that is! It costs twice as much as fiberglass. That’s why it’s not an easy decision at all. Rockwool is superior in longevity and acoustic performance, but the price won’t suit everyone. 

Final Words

When it comes to soundproofing, the option is always between Rockwool and fiberglass. Both materials are effective and they each offer a lot of benefits. However, they also have important drawbacks to consider. The biggest difference, by far, is cost. 

Rockwool seems to be the best of the two options, but if your budget doesn’t allow it, you’ll have to compromise. We recommend you use a combination of the two. For example, Rockwool should be used in damp areas, while fiberglass is best used in dry areas. 

Whatever you do, make sure you choose the right thickness for your needs. Do your research, speak with professionals, and don’t be afraid to ask questions. Also, look for cheaper prices! Though Rockwool is quite expensive, it can be found at lower prices if you take the time to look. That way, you can save a little and enjoy high-quality soundproofing. 

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