Denim Insulation Vs. Mineral Wool (Rockwool) – Which To Choose?

Insulation regulates home temperatures; it keeps our houses protected during the winter and the blistering heat of summer. Most importantly, it helps avoid excess moisture and maintains the home's structure. The insulation material matters to work effectively. So if you're stuck between choosing Denim insulation or Rockwool, don't worry because we did all the research for you!

Mineral Wool or Rockwool is one of the best choices when it comes to picking the kind of material for insulation. Rockwool fibers have molten rocks and mineral oils components that make insulation breathable, water-resistant, and unsusceptible to noise. 

It's natural to be concerned and picky in terms of choosing the right material for your insulation. After all, this factor influences how good the insulation is going to turn out. You can read further to know about Rockwool material.

A denim insulation and mineral wool comparison, Denim Insulation Vs. Mineral Wool (Rockwool) - Which To Choose?

Factors Determining Why Rockwool Is The Best Choice

Rockwool is recognized in almost all parts of the globe, utilized in residential and building projects. It's one of customers and professionals' top choices when choosing the right material for home insulations.

Mineral wool

Here is a list of factors that make Rockwool everyone's choice:


Rockwool is made of molten rock, basalt, anorthosite, cemented briquettes, mineral oil, and recycled steel slag heated all together and turned into fibers. These fibers balance the Rockwool fibers and make them absorbent to moisture and water.

The material is geothermal with high thermal efficiency. Your house may not need any additional heating and cooling because of the strong thermal resistance the wool is capable of. What's more, this lowers your energy bills.

The basalt and steel slag present in the material provides durability and versatility when it comes to insulation. These compounds make the material sponge less dust to make you itch.

The U.S. Department of Energy states that Rockwool has a higher R-value than fiber and denim insulation ranging from 3.0-3.3 per inch.

There is 75% of industrial waste is found in Rockwool insulation. It's hydrophobic. So, in case it danks and dries conversely, it has the capability to still maintain its R-value.

Click here to see this Roxul Rockwool insulation on Amazon.


Rockwool's innovative materials reduce noise. It blocks sound waves and dull vibrations that can disturb your home's calmness. This advantage goes well with homes located near bustling roads and crowded neighborhoods to minimize external noise barriers.

Along with that, since the material is made out of rock, it's non-combustible and guarantees extra safety to houses and buildings in case fire events take place.

It also consists of compression-resistant materials, so it's best to use for roofing boards and bonded panels specifically for renovation projects in your home.

House thermal insulation with mineral wool

Rockwool has breathable materials that enhance the air quality of your home by providing thermal comfort. Additionally, this feature prevents bacteria from developing inside your house. At the same time, this terminates pests infestations.

It is also safe for the environment since it cuts down non-renewable energy sources such as carbon footprint, electricity, and gas that will likely cause air pollution.

All things considered, Rockwool has components that are fit to be resilient. It can last for a long period of time. You won't have to sweat too much in dealing with its repairs and maintenance, either.

Easy Installation

On top of all the sustainable and natural materials present in Rockwool, it's proven to contribute a lot of good things to both the home and the environment. Not to mention, it's so easy to install you can do this all by yourself!

This YouTube video from Home Repair Tutor can show you how simply it's simply.

Does Rockwool Need An Air Gap?

As mentioned above, Rockwool insulation is breathable, so it does need to require any air gap but there can be cases where it's necessary to have one, specifically when putting insulations in dormer roof.

It's recommended that insulating dormer roofs require 320-355 mm of insulation within the rafters. That said, Rockwool should be built up in 150 mm and 100 mm layers to achieve the required thickness. So when it's possible and where it's applicable, an air gap can be established.

Back view of two unrecognizable worker man in overalls working with rockwool insulation material

What Are The Drawbacks Of Rockwool Insulation?

It's always right to check and balance the material before purchasing since there could be possible reasons that could be of disadvantage to you.

Here, we listed a few of the drawbacks that you need to look at when getting a Rockwool insulation:

  • Upon installation, it's mandatory to wear protective gear such as goggles, an N95 face mask, and sleeves as a safety measure from tiny silvers of the material that may enter your skin pores, eyes, and lungs.
  • Rockwool has high pH levels and nutrient solutions and is inclined to pH shifts. It's best to observe the pH levels in your body because they may be affected in some ways.
  • Rockwool is not biodegradable so when you throw it away, it does not decompose.
  • Rockwool has a restricted root environment and a low buffering capacity for nutrients. However, this doesn't weaken its water retention capacity.

Some of the disadvantages can risk your health, especially if you're not careful. It's best to have a keen eye on the preparations before doing any home insulation.

On the other hand, some factors can be adjusted with thorough understanding. At the end of it all, it's up to your considerations on whether or not Rockwool insulation best suits your liking.

Roll of mineral wool lying on the wooden floor

What Are The Pros And Cons Of Denim Insulation?

If you're considering Denim insulation as another option, we also offer you answers about this type of material.

Denim insulation literally comes from the fabric itself.  It means home insulation with the material that contains recycled denim jeans. It's fit to insulate walls, attics, and crawl spaces.

It has an average R-value of 3.5 per inch and is known as an alternative to fiberglass.

Recycled blue jean denim insulation

Before choosing Denim insulation, you can go over this list of pros and cons. This can provide you some considerations to think about!


  • Since it contains recyclable denim jeans material, it can still be recycled again and used for insulation despite the fact that you previously used it.
  • Denim insulation is eco-friendly and guarantees 100% recycled materials in it.
  • Unlike Rockwool materials, it doesn't release tiny silvers and fiber that can irritate.
  • It's manageable and easy to handle, and you don't have to gear up too much when installing it.


  • Denim insulation is expensive and can cause around $1.12 per square foot.
  • It's hard to cut because of the components of dense mats.
  • Denim insulation can be inflexible, tight, and fuzzy, making it difficult for you to stretch it in cases where there's an empty spot. But there are Denim insulation products available in rolls, so that could be a solution to this flaw.
  • The material is difficult to find! Home centers may require you to order in large quantities or special orders. Buying it online goes the same, with the risk of damages that can possibly occur in the shipping process.


Rockwool insulation is, at its core, universal in application. It's beneficial for the home, the environment, and your energy consumption costs. Finally, yet importantly, the last call is up to you. Let your choice be one thing that serves your interest the most.

You might also want to visit the following articles on our page for related topics:

How Long Does Mineral Wool Insulation Last?

Can Mineral Wool Insulation Be Left Exposed?

Does Mineral Wool Insulation Need A Vapor Barrier?

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