Rockwool Insulation For Soundproofing – All The Facts!

Insulation options come in all shapes and sizes, but Rockwool insulation is often near the top of every “best of” list out there. Customers love what it brings to the table, and how there is virtually no maintenance required after the fact.

What is Rockwool Insulation? This is a stone wool batt insulation that also serves as a sound barrier so people can have a very closed off and quiet building. Whether it is used for exterior walls, basement, crawlspaces, or even professional recording rooms, it makes a lot of sense for people who want premium quality.

Is it the best option out there for insulation in the eyes of soundproofing? Most people believe so, but it is important to analyze all the factors that make it such a worthwhile investment.

This is a complete breakdown of Rockwool insulation, providing information that might help people make that final decision.

What is Rockwool Insulation

Rockwool Insulation

The simplest way to describe Rockwool insulation is that it is a comfortbatt made up of stone wool. It not only helps with weather and fire protection, but it helps with sound absorption as well.

This is perfect for those who are dealing with any type of sound issues inside or outside of a home. Even if it is just one specific area, it can work.

Its main competitor, fiberglass insulation, does not quite live up to the same standards. While fiberglass is cheaper, Rockwool is more durable, absorbs sound much better, helps control temperature, and so much more.

Why Invest in Rockwool Insulation

Insulation is not the most expensive thing when it comes to construction, but it plays a vital role in making sure that the inside is of high quality.

Whether it is an office building, a home, or anything in between, not having to deal with sounds coming from outside is certainly beneficial. Even the thickest walls need insulation, which is why Rockwool insulation is so highly regarded.

Thermal Insulation

The first thing most people think of when purchasing any new insulation is to help with temperature control. Indoor temperatures need to be at a comfortable level regardless of what is going on outdoors.

Sometimes it is pretty easy, but wasting a lot of energy on heating up or cooling down a building can add up if there is leakage.

There are many different thickness options, but Rockwool definitely lives up to expectations for all the different uses. Finding the right fit is important to make energy bills go down to a decent level.

It is a battle that a lot of people are forced to deal with for one reason or another, but there is no real reason to spent a lot of money on electric bills if insulation can help a lot.

Heat Resistant

One of the most insane things that can happen to any building is a fire. In some cases, insulation actually contributes to the fire, instead of helping limit it as much as possible. (source)

Rockwool’s stone wool fibers are a bit different. Many are surprised to see that it can hold up against very strong fires to help slow the spread as much as possible. It just does not melt, no matter how hot a fire gets.

Sound Absorption

This is the number one reason why people initially start looking at Rockwool. It has gained a reputation of being the best for acoustics, and having that option certainly helps people who need things to be a little quieter. (source)

Some people will look into Rockwool because they feel like they need something to help block out noisy road sounds or other disturbances around the neighborhood.

In other scenarios, using this insulation for a particular room used for recording makes a lot of sense. Finally, a home entertainment room might need a little more quietness, not to mention a way to limit sound from spreading to other parts.


What is the big deal if insulation is breathable? By having breathability, moisture can find it very hard to have any impact whatsoever.

Keeping the inside of a building very dry and free of mold helps out a lot, which is why people who live in damp areas are so quick to invest.

Moisture is something that might not do that much damage initially, but it can really start to add up if a person leaves it unattended.

This is why so many people are willing to invest in something that helps with overall dampness, fixing the issue before it even becomes one.

Common Rockwool Questions

Rockwool Mineral Wool FAQ

Not convinced that Rockwool is the way to go? There are a lot of people who have questions before investing. It is important to know more about this insulation so that everything goes as smoothly as possible.

The last thing people want to do is spend a lot of money by using this premium insulation option, only to not necessarily need it everywhere. When it is essential, it is worth spending that extra bit of money on something that will provide great value.

How Does Rockwool Compare Directly to Fiberglass?

Insulation comes in two pretty distinct options, as fiberglass and mineral wool, such as Rockwool , definitely have advantages and disadvantages. Fiberglass is the established option so many people have relied on over the years, but some people are just not satisfied with what it brings to the table.

It is important to point out that fiberglass will still always have a place in the market because it is extremely affordable, very easy to install, comes in many different sizes, and insulates very well.

The difference is, mineral wool insulation does a lot of the same things, only better. Whether it is R-value, sustainability, sound deadening properties, water resistance, fire resistance, and more, it just seems like an option that is worth the extra investment.

Houses do tend to use a combination of both installations, and they are certainly nothing wrong with that. The more economical fiberglass insulation can go in the more common areas, with mineral wool used to sparingly when extra sound control is needed. If it was a little more affordable, people would use mineral wool just about anywhere, but that is just not the case at this point.

What Soundproofing Material Combine Well with Rockwool Insulation?

Since this insulation takes care of the cavity behind the wall, there are still plenty of opportunities for people to use soundproofing material on the outer side. For example, putting up panels can help quite a bit, and it is a pretty cheap way to help with the entire process as well.

Other setups work as well, but most people want to take care of the major sounds initially. Only those who are looking to turn a room into a more professional type of studio will need to invest in a different soundproofing option heavily.

Difference in Cost Between Rockwool and Fiberglass Insulation?

On average, Rockwool tends to cost about 1.5 times the amount of fiberglass insulation. That might not seem like that much money when only looking at a few areas, but it starts to add up pretty significantly once an entire building is considered.

The money should not be too big of an issue, simply because the insulation will last a long time. However, as stated before, it might not make that much sense for some people to invest in high-quality insulation for some of the lower impacted areas.

What is the Life Expectancy of Rockwool?

If installed correctly, Rockwool has a lifetime guarantee. People should be pleased about this, since it can do its job and not really need any maintenance whatsoever.

There are some panels that end up getting compromised for one reason or another during installation, but this is usually not going to happen with just about any setup out there.

How Does Roxul Insulation Relate to Rockwool?

For people who live in North America, they might be familiar with Roxul insulation. This is actually another name for what Rockwool offers as a company. Rockwool is the main company, while Roxul is another name that sticks around for marketing purposes. In reality, the name Roxul has been replaced with Rockwool. 

The lack of differences is good for people who are looking to shop just about anywhere. Both companies have a very trusted name in the industry, and they are now coming up with creative new options all the time.

Where to Buy Rockwool Insulation?

Now that this type of insulation is as popular as ever before, there are more and more locations that carry it. Go to a local store that focuses on construction and home improvement, and the insulation options will be there. Many of them will cover different sizes as well so people can get exactly what they need.

Shipping is also readily available, and no one should completely overlook this option if they do not live particularly close to a store that has a sufficient amount of options.

You can easily find this type of insulation on Amazon and you can also order it directly from Home Depot.

Is it Always Necessary to Fill an Air Cavity?

Filling Air Cavity With Rockwool

There are plenty of buildings that have empty air cavities, but it does not make a lot of sense from a few angles. For starters, it is not going to provide any type of assistance in the long run.

Sure, some sound will die within that air cavity there in the first place, but it is nothing like what insulation can provide.

Another reason why filling the air cavity with something is better than nothing is that it can help act as another barrier before something more important is damaged. Whether it is fire, water, pests, or anything else, it is just one more way to keep everything out.

It also takes away the hollow feeling that a lot of walls have, which can be frustrating from a soundproofing perspective. No one wants to be in an echo chamber, and they do not want to tap against the wall and feel like it is very cheaply made. By installing insulation, it feels like a complete wall that can really provide some value.

Will there ever be a time where fiberglass insulation is gone completely?

The popularity of Rockwool is very apparent, but it is not quite ready to take over just yet. The biggest obstacle is finding ways to lower the cost so that more and more people can experience this unique type of insulation.

There are always going to be people who want to keep fiberglass as the cheap, dependable option that has worked for decades. Maybe Rockwool will one day take over, but it is not happening just yet.

What is the R-rating for Rockwool?

An R-rating is used to give people an accurate representation of what a material can do to resist thermal transfer. Fiberglass has always had a reasonably good R-value of around 2.5 per inch. However, Rockwall can reach about 3.2 per inch, which shows a pretty significant jump.

The US Department of Energy does point out that the rating can vary a bit depending on installation process, thickness, and other factors. On average, there will be a pretty significant difference between Rockwool and fiberglass, which is one reason why people are so quick to jump to this better option.

Is there a blowing wool option for Rockwool?

There is no blowing wool insulation currently made by Rockwool. They only manufacture back, board, and type forms for people to use. This is a minor inconvenience for some people, but worth noting if blowing wool is what is being looked for.

Why Choose Rockwool Insulation

This is a soundproofing website, so any insulation is going to be viewed from that perspective. With that being said, even if this insulation only had adequate soundproofing qualities, it would still be the best of the best.

It has found ways to improve on what makes fiberglass insulation so popular, and prices continue to drop to make it more affordable for everyone.

Anyone looking to take their sound inside a building to the next level should consider this a no brainer option. For areas that are very prone to being loud in general, make sure that as many walls as possible are covered with this insulation.

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