What Type Of Insulation Is Best For Soundproofing In 2021

You all know that insulation is one of the properties of some of the specific materials that prevent the movement of energy, whether it is electrical energy, heat energy, or sound energy. It all depends upon which type of insulation materials you are using.

There are some insulations that have the capabilities to prevent the movement at least of two energies like heat energy and sound energy. Spray foam, Rockwool, Cellulose, Fiberglass Vs Denim insulation are one of them.

Yes, you are right the above insulations are used for heat as well as sound insulation. You will get the twin benefits by using these insulations. You can save your power consumption as well as enjoy soundproofing also.

What Is Soundproofing

Soundproofing means reducing the intensity of sound or blocking the sound. Actually, there are so many ways to reduce the intensity of sound such as by increasing the distance between the source and the receiver, using noise barriers, or creating the cavity in between them.

Basically, soundproofing is based on 5 principles and they are as follows. Also, it is very important for us to know these principles so that we can know which material has what function as well as where this material is going to be used.

Principles Of Soundproofing

Soundproofing is based on the 5 basic principles, if you follow these principles for your soundproofing project then definitely you will get a better result.

1. Mass

Thicker, denser, and heavier objects are able to block sound effectively. Mass-loaded vinyl and soundproof drywall is the best example of it.

When you add these types of stuff to your wall, ceiling, and floor then you are adding extra mass which helps you to reduce noise.

2. Distance

You can reduce the intensity of sound also by increasing the distance between the source and the receiver. But you can’t change the distance of source and receiver everywhere, that’s why apply it wherever possible.

3. Damping

You can reduce the intensity of sound by stopping the vibrations and you all know that the sound is produced by vibrations.

Dampening is to dampen the vibrations and if you dampen the vibrations then indirectly you reduce the intensity of sound and you can achieve it very easily with the help of damping elements.

4. Decoupling

Decoupling is the process of creating a cavity or dead air zone between two walls so that when the sound waves enter into this zone, it becomes inactive.

This dead air zone is created with the help of decoupling elements like resilient channel, Hat channel, or Reducto clip.

5. Absorption

As the name indicates its function, here the intensity of sound is reduced by absorbing the sound waves. This principle is mostly used there, where good sound quality is required.

Acoustic panels and acoustic foam panels are good examples of it. You can easily install foam panels without damaging walls but the proper placement of the acoustic foam panel is very important for better soundproofing.

Here you came to know the principles of soundproofing as well as you also got a little bit of information about materials. Now you have to plan the strategy according to the principles so that you could use almost all the soundproofing principles in your project.

Each principle has its own merits, so if you add all these principles to your soundproofing project then you will see good results.

[Read]: Best underlayment for laminate flooring to reduce noise

Now let’s see what type of insulation is best for soundproofing,

What Type Of Insulation Is Best For Soundproofing

The best type of insulation for soundproofing is blown-in cellulose insulation, fiberglass insulation, Rockwool insulation, and denim insulation. All these materials have excellent noise-reducing properties so they insulate sound well.

At the bottom, we have made a comparison table for these 4 insulating materials so that you come to know which one is better, and you could choose a good insulating product for your soundproofing project.

As you know that the soundproofing is a combination of the five principles that’s why all the insulating materials used in them come under soundproofing. Here we will discuss all these best insulation materials which are used for soundproofing.

Generally, Soundproof Insulations are classified as below,

  • Spray foam Insulation
  • Rockwool Insulation
  • Blown-In Cellulose Insulation
  • Fiberglass Insulation
  • Acoustic Foam Insulation
  • Denim Insulation
  • Foam Board Insulation

Now let’s see each insulation in detail so that you could be clear what type of insulation is best for soundproofing.

1. Spray Foam Insulation

Spray foam insulation is an expanding foam that can be sprayed onto the metal walls, walls cavities, stud cavities, joist cavities, and hollow doors, etc.

This spray foam insulation is mostly used for thermal insulation. It is a very effective product in stopping the movement of heat and cold energy. Generally, spray foam insulations are of two types: open cell and closed cell spray foam insulation.

Open-cell spray foam insulation:

Open-cell spray foam is made of polyurethane. It expands around 150 times its original volume and when it goes hard its weight becomes 1/2 lb/ft3 which is very less as compared to closed cell spray foam.

Its open-cell structure does not block the heat or cold energy effectively as compared to closed cell spray foam that’s why its R-value is 3.6/inch which is very less as compared to closed cell spray foam.

While open-cell foam is better than closed-cell foam, when it comes to soundproofing, but it is not a very effective option as compared to other soundproofing insulations. It is able to reduce only 2 to 4 dB noise level because it has less mass to absorb sound waves.

Pros:

  • It expands around 150 times its original volume
  • Reduce noise effectively than closed cell spray foam, but it is not a very effective option as compared to other soundproofing insulations.

Cons:

  • It reduces noise but it is not a very effective option as compared to other soundproofing insulations.
  • Less R-value (3.6/inch)
  • Less thermal insulation as compared to closed cell spray foam
  • Light in weight (1/2 lb/ft3)
  • It is hazardous so always check its MSDS before using it.
  • Need professional to install it.

Closed-cell spray foam insulation:

Closed-cell spray foam is made of polyethylene. It expands around 30 to 50 times its original volume and when it goes hard its weight becomes 2 lb/ft3 which is very heavy as compared to open-cell spray foam.

what type of insulation is best for soundproofing

Its closed-cell structure blocks the heat or cold energy effectively as compared to the open-cell spray foam therefore this product is considered an effective product for thermal insulation. Its R-value is 6/inch which is greater as compared to open-cell spray foam.

Due to its closed-cell structure, it is more rigid than open-cell foam that’s why they are not effectively reduced the transmission of noise.

Pros:

  • It expands around 30 to 50 times its original volume
  • Heavy in weight (2 lb/ft3)
  • High R-value (6/inch)
  • Good thermal insulation

Cons:

  • Negligible noise reduction
  • It is hazardous so always check its MSDS before using it.
  • Need professional to install it.

2. Rockwool Insulation

Rockwool and fiberglass insulation both are mineral wool insulation but they both are made from different minerals. Rockwool insulation is made from rock and stone and fiberglass insulation is made from glass.

What Type Of Insulation Is Best For Soundproofing In 2021

Each of its fibers forms a honeycomb-like structure in itself and resists the air passing through them and these things make it a good sound insulator as well as a good heat insulator also.

The 2″ Rockwool Acoustic Mineral Wool Insulation 80-8lb has an overall NRC rating is 0.9, which indicates that it is a good sound absorber.

Its density is 8 lb/ft3 which is very good and indicates that this product is denser and heavier, and you all know that a heavier, denser, and thicker product effectively blocks the sound.

Its natural stone & recycled material makes Rockwool insulation excellent fire-resistant. It resists temperature up to 2000 degrees Fahrenheit. It has greater dimensional stability and lower thermal drift, also it is naturally hydrophobic.

It also resists the growth of mold, mildew, rot, and bacterial growth and makes your home safer. Rockwool insulation is generally available in Comfort Batt, Comfort Board, & Safe ‘n’ Sound.

Comfort Batt:

Actually, comfort batt is a semi-rigid Rockwool thermal batt insulation, which delivers excellent R-value that’s why it is used inside homes on walls connected to the exterior.

What Type Of Insulation Is Best For Soundproofing In 2021

It is non-combustible, fire-resistant, and a good sound absorber. Comfort batt is mainly used for twin applications like thermal as well as sound insulation. This stuff has less density (2 lbs/ft3) as compared to Safe n Sound and Comfort Board. (Data Sheet)

Pros:

  • Non-combustible
  • Excellent R-value
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Fire resistant
  • Good sound-absorbing properties
  • Water & Moisture resistance
  • Mold & Mildew resistant
  • Lightweight and easy to install
  • Not produce toxic smoke or promote flames

Cons:

  • Less dense as compared to Safe n Sound and comfort board
  • It is only used inside homes on walls connected to the exterior
  • Itchy
  • PPE required

Comfort Board:

Comfort board is an exterior non-structural rigid mineral wool thermal insulation sheathing that provides the insulation around the building. It is non-combustible, vapor permeable, fire-resistant, water repellent, and an excellent sound absorber.

What Type Of Insulation Is Best For Soundproofing In 2021

Comfort boards are available in different thicknesses with different densities. Its most popular and trending brand in soundproofing is comfort board 80. It is mainly used for twin applications like thermal as well as sound insulation.

The overall NRC rating of 3inch comfort board is 0.9 and its density is 8 lbs/ft3 which is very good, and also it is a good sound absorber. (Data Sheet)

Pros:

  • Non-combustible
  • Good R-value
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Fire resistant
  • Good sound absorbent (NRC rating 0.9)
  • High denser
  • Water & Moisture resistance
  • Mold & Mildew resistant
  • Easy to install
  • Not produce toxic smoke or promote flames

Cons:

  • It is used for exterior non-structural insulation sheathing purposes only.
  • Slightly heavy in weight
  • Itchy
  • PPE required

Safe ‘n’ Sound:

Safe n sound is a stone wool batt insulation that is specifically designed for internal wall partitions, floors, and ceilings. (Brochure)

What Type Of Insulation Is Best For Soundproofing In 2021

It has excellent sound-dampening properties. 3″ Safe n Sound overall NRC rating is 1.05 which is very excellent. Safe ‘n’ Sound is not designed for thermal insulation.

It is a non-combustible, fire-resistant, and excellent sound absorber. They are available only in 3″ & 6″ thicknesses with a density of 2.4 lbs/ft3. (Data Sheet)

Pros:

  • Non-combustible
  • Fire resistant
  • Excellent sound absorbent
  • Overall NRC rating 1.05
  • Water & Moisture resistance
  • Mold & Mildew resistant
  • Lightweight and easy to install
  • Withstanding temperatures up to 2150 degrees Fahrenheit (1177 degrees C)
  • Not produce toxic smoke or promote flames

Cons:

  • It is used for exterior non-structural insulation sheathing purposes only.
  • Not for thermal insulation
  • Here you will get to see only one benefit and that is an excellent noise reduction
  • Itchy
  • PPE required

3. Denim Insulation

Denim insulation is the most popular recycled insulation product which is made up of cotton recycled insulation products. It is fire retardant as well as mold & mildew repellent. (Data Sheet)

What Type Of Insulation Is Best For Soundproofing In 2021

It is available in batts and loose-fill. It is used in walls, ceilings, floors, crawl spaces as well as it is also used to make acoustic panels, thermal packaging, HVAC duct liners, and spa insulation.

This denim insulation also works on the same principle as other fiber insulation. This material itself doesn’t provide much thermal resistance but it traps the air in between their pockets of fibers very effectively that’s why its NRC rating is also very good.

Denim has a good NRC rating which is 1.15 as well as its STC rating is also good which is 45.  Denim cotton insulation doesn’t cause any itching or irritation even if you install it without gloves, safety goggles, or a dust mask. But I wouldn’t recommend it because it is a little bit dusty so always work with safety.

The R-value of this product is also very good which is 3.5/inch but their 1.5-inch thick denim insulation batt actually measured 1 inch hence it has a lower R-value than it claims.

Pros:

  • Fire Retardant
  • Mold & Mildew Repellent
  • Twin benefits: Thermal insulation as well as Better noise reduction
  • Available in batts & loose fill
  • Good R-value 3.5/inch
  • Denser (3lbs/ft3)
  • Friction fit
  • No Itchy
  • It can easily wrap around pipes, wires, and outlets in stud bays
  • It doesn’t contain any VOC (Volatile Organic Compound)
  • Excellent acoustical properties (NRC 1.15)
  • Good STC rating (STC 45)

Cons:

  • The R-value of this product is also very good which is 3.5/inch but their 1.5-inch thick denim insulation batt actually measured 1 inch hence it has a lower R-value than it claims.
  • Difficult to fluff up
  • It never regains its shape
  • It is a little bit dusty
  • Difficult to cut with a knife but scissors work
  • Not Water repellent
  • It is costly (1.24/sqft)

4. Blown-In Cellulose Insulation

Cellulose insulation is made up of discarded recycled paper and cardboard boxes, treated with boric acid or ammonium sulfate to prevent mold and mildew.

What Type Of Insulation Is Best For Soundproofing In 2021

This cellulose insulation also works on the same principle as other fiber insulation. This material itself also doesn’t provide much thermal resistance but it traps the air in between their pockets of fibers very effectively that’s why its NRC rating is also very good.

Cellulose batt insulation is installed in the same way as denim but installing blown-In is completely different. It can be installed in two ways with dry or damp fiber.

Dry fiber is most commonly used for retrofits in open attics but it can also be used in enclosed walls and cathedral framing cavities.

It is fed into a hopper which breaks down the clumps of cellulose and blows it through a two to three-inch diameter flexible hose.

Damp cellulose on the other hand is used for open wall cavities in new construction. The fiber is mixed with water and then spray it into the wall stud cavity. The water dampens the surface of the wall stud cavity and creates a sticky contact bond so that cellulose fiber stick well.

The wall cavities are overfilled and then scraped flat just like spray foam insulation.

Windows, doors, and electrical boxes must be protected with plastic sheathing and tape prior to installation.

You must not use too much water as well as do not close up the wall before cellulose dries out because it can lead to mold, mildew, and rot.

Cellulose is hygroscopic means that it attracts and holds water causing the chemical used in cellulose to make it potentially corrosive in a wet environment. Also, it is very dusty so always work with safety.

The water repellency of this material is a little disappointing but it is an excellent fire retardant. It has better acoustical properties whose NRC rating is 1 and STC rating is 44.

Also, it resists heat well which we can find out by its R-value and its R-value is 3.5/inch which is good. So by using this insulation you can enjoy twin benefits like sound as well as thermal insulation.

Pros:

  • Fire Retardant
  • Twin benefits: Thermal insulation as well as Better noise reduction
  • Available in batts & loose fill
  • Good R-value 3.5/inch
  • Denser (3lbs/ft3)
  • No Itchy
  • It doesn’t contain any VOC (Volatile Organic Compound)
  • Excellent acoustical properties (NRC 1)
  • Good STC rating (STC 44)
  • Not produce toxic smoke or promote flames

Cons:

  • Dusty
  • Not Water repellent
  • It is costly (1.2/sqft)
  • PPE required
  • Corrosive in a wet environment
  • A blowing machine is required

5. Fiberglass Insulation

Fiberglass insulation is also a mineral wool insulation as Rockwool but it is made of glass.

What Type Of Insulation Is Best For Soundproofing In 2021

The working principle of fiberglass insulation is the same as Rockwool insulation. Each fiber of this fiberglass insulation makes a honeycomb-like structure in itself and resists the air passing through them and this thing makes it a good sound insulator as well as a good heat insulator also.

The R-value of Fiberglass insulation ranges between 2.5 to 3.7/inch which is lesser than the R-value of Rockwool insulations.

If you compare it’s one of the batts of R-30 to Rockwool R-30 then found that it is lighter and less dense as compared to Rockwool insulation. Also, its NRC rating ranges between 0.5 to 1.

Some of the product of fiberglass insulation is fluffy, they couldn’t maintain their shape in walls and attics so we don’t get the results as per their mentioned R-value.

Fiberglass insulation isn’t waterproof it can absorb water and moisture become compacted and lose all insulating properties. Also, it is not fire-resistant. It is a little bit difficult to install due to its fluffiness so it needs to be secured with staples.

Here we are giving a brief description of the most popular and trending product of fiberglass insulation so that it is easy for you to choose a good product. (Brochure)

Unfaced Insulation:

From the name you get to know that there is no paper or foil covering over this insulation. This insulation is mainly used for improving the R rating by adding R values but it should be installed just behind the faced insulation.

What Type Of Insulation Is Best For Soundproofing In 2021

This insulation is suitable for interior partitions of walls. It is not vapor retarder or water-resistant that’s why avoid using this insulation over wetted areas like bathrooms.

This insulation also helps to improve sound transmission class. It is light in weight. The density of this insulation is very less as compared to denim, cellulose, and Rockwool insulation.

Pros:

  • Non-combustible
  • Inexpensive
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Fire-resistant and does not catch fire easily
  • Withstanding temperatures up to 1000 degrees Fahrenheit (540 degrees C)
  • Good sound-absorbing properties
  • Mold & Mildew resistant
  • Light in weight

Cons:

  • It is not a vapor retarder or water-resistant
  • Less dense
  • It doesn’t maintain its shape
  • Produce toxic smoke
  • Itchy
  • PPE required

Faced Insulation:

From the name you get to know that there is a paper or foil covering over this insulation. This craft paper covering helps to protect your insulation from vapor and also you can secure its flanges on the stud with the staple.

What Type Of Insulation Is Best For Soundproofing In 2021

This insulation is mainly used as the first layer in new construction. It is easy to install as compared to unfaced fiberglass insulation.

Always remember that at the time of installation its paper side should always facing outward and do not use this insulation over the more wetted areas like bathrooms if you want to use this insulation in more wetted areas then always use plastic sheathing as a vapor barrier.

Pros:

  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Vapor retarder but do not use in more wetted areas
  • Good sound-absorbing properties
  • Mold & Mildew resistant
  • Light in weight

Cons:

  • Less dense
  • A little bit expensive as compared to unfaced fiberglass insulation
  • Its craft paper catches fire easily
  • Do not use in more wetted areas
  • It doesn’t maintain its shape
  • Produce toxic smoke
  • Itchy
  • PPE required

Atticat Blown-In Insulation:

Blown-In insulation is also called loose-fill insulation. It is mainly used in attics and irregularly shaped areas. But you can also be used it in finished areas and around obstructions.

What Type Of Insulation Is Best For Soundproofing In 2021

It is fed into a hopper which breaks down the clumps of fiberglass and blows it through a two to three-inch diameter flexible hose to the required place.

Pros:

  • Non-combustible
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Fire-resistant and does not catch fire easily
  • Withstanding temperatures up to 1000 degrees Fahrenheit (540 degrees C)
  • Good sound-absorbing properties
  • Mold & Mildew resistant
  • Light in weight

Cons:

  • It is not a vapor retarder or water-resistant
  • Less dense
  • A little bit expensive than unfaced fiberglass insulation
  • Produce toxic smoke
  • Itchy
  • PPE required

Fiberglass 703:

Fiberglass 703 is a semi-rigid board that is mainly used for equipment, vessels, and air conditioning ductwork. This product has a good R-value which is 8.7 and that’s why this product is mainly used for heat insulation. (Data Sheet)

What Type Of Insulation Is Best For Soundproofing In 2021

It has also good sound-absorbing properties along with a heat barrier. These unfaced boards are normally finished with reinforced insulation cement or weatherproof mastic.

Pros:

  • Non-combustible
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Fire-resistant and does not catch fire easily
  • Better thermal resistance
  • Good sound-absorbing properties
  • Mold & Mildew resistant
  • Light in weight

Cons:

  • It is not a vapor retarder or water-resistant
  • Less dense
  • A little bit expensive than unfaced fiberglass insulation
  • Produce toxic smoke
  • Itchy
  • PPE required

6. Acoustic Foam Insulation

Acoustic foam is also a good, cheap, and affordable option for soundproofing. The acoustic foam absorbs the sound and converted it into a small amount of heat.

What Type Of Insulation Is Best For Soundproofing In 2021

Acoustic foam is mainly used to improve the sound quality in recording studios, home theatres, cinema halls, auditoriums, etc.

Acoustic foam reduces echo and reverberation by reducing the reflection of sound and if the reflection of sound is reduced then the amplification of sound is reduced as a result of which you get to see a significant reduction in sound.

Basically, there are two types of foam: Open cell foam and Close cell foam

Open-cell foam insulation:

Open-cell spray foam is made of polyurethane. Its open-cell structure does not block the heat or cold energy effectively as compared to closed cell spray foam that’s why its R-value is very less as compared to closed cell spray foam.

What Type Of Insulation Is Best For Soundproofing In 2021

While open-cell foam is better than closed-cell foam, when it comes to soundproofing, but it is not a very effective option as compared to other soundproofing insulations.

Pros:

  • It doesn’t contain any VOC (Volatile Organic Compound)
  • Twin benefits: Thermal insulation as well as Good noise reduction
  • Good for soundproofing
  • It makes sound quality better
  • Light in weight
  • It is a fire retardant
  • Reduce noise effectively than closed-cell foam, but it is not a very effective option as compared to other soundproofing insulations.
  • Installation is very easy

Cons:

  • Less R-value than closed-cell foam
  • Less thermal insulation as compared to the closed-cell foam
  • Less dense between 0.4 and 1.2 lbs/ft3

Closed-cell foam insulation:

Closed-cell foam is made of polyethylene. Its closed-cell structure blocks the heat or cold energy effectively as compared to the open-cell spray foam therefore this product is considered an effective product for thermal insulation.

What Type Of Insulation Is Best For Soundproofing In 2021

Its R-value is greater as compared to open-cell spray foam. Due to its closed-cell structure, it is more rigid than open-cell foam that’s why they are not effectively reduced the transmission of noise.

Pros:

  • Twin benefits: Thermal insulation as well as Sound insulation also
  • High R-value
  • Good thermal insulation
  • Moisture resistance
  • Fire retardant
  • High dense
  • Suitable for interior and exterior environment

Cons:

  • Negligible noise reduction
  • Heavy in weight

7. Foam Board Insulation

These three foam boards EPS, XPS, & Polyiso are very similar forms of board insulation used in home and building construction industries.

Actually, foam boards are made of two materials which are as follows,

  • Polystyrene
  • Polyisocyanurate

Now let’s see each in brief,

Polystyrene:

Polystyrene comes in two forms Extruded and Expanded forms. The Extruded form is also called XPS (Extruded Polystyrene) and the Expanded form is called EPS (Expanded Polystyrene).

a. Expanded Polystyrene Foam Board (EPS)

Actually, the liquid polystyrene is dropped in water to form droplets or beads.

The EPS beads are contained in a mold and then heat or steam is applied to it which causes the small beads to expand and then they mold into that mold shape.

What Type Of Insulation Is Best For Soundproofing In 2021

While each individual bead is a closed cell but there is significant open space between the beads. These EPS beads are molded into large sheets or blocks and cut by hot wire machines into thinner sheets or any special shapes or forms.

EPS is made of 98% air and just 2% plastic. It can be easily dissolved in acetone and it barely leaves any residue. This high percentage of trapped air makes it an excellent insulator.

It can be used on roofs, in walls, in floors, in insulated concrete forms or ICF blocks, in structurally insulated panels or sips, and in an exterior insulated finish system or EFIS.

And outside the construction industry, it is used in packaging peanuts, cushioning for fragile items, and disposable food containers.

The expanded polystyrene is basically an open cell structure, that’s why it absorbs the sound easily and helps to reduce the transmission of sound but it is not an effective solution as compared to the other soundproofing stuff.

And also due to its open cell structure, it doesn’t block the heat effectively and that’s why it has less R-value than the R-value of XPS and Polyiso.

Pros:

  • Inexpensive than XPS & Polyiso, it’s 4′ x 8′ x 1″ thick sheet costs $16.25
  • This 1″ sheet has an R-value of about 3.18 to 4.6
  • Thermal drift refers to the loss of R-value over time because the air trapped inside the insulation dissipates. The big advantage of EPS is that it has no thermal drift or loss of R-value over time.
  • Good for sound insulation than XPS and Polyiso
  • No Off-gassing
  • No CFCs or even HCFCs (hydrochlorofluorocarbons)
  • The greenest choice among all the three insulations types
  • Mold & Mildew resistant
  • 100% Recyclable

Cons:

  • Less R-value than XPS and Polyiso
  • The insulation panels are coated in a bromine fire retardant called HBCD (hexabromocyclododecane) which is dangerous to health.
  • EPS also attract termites and ants
  • Less dense than other soundproofing stuff
  • Not good for thermal insulation
  • Water can penetrate in the EPS because the space between the beads
  • It is also flammable
  • It doesn’t breakdown in sunlight and it is not biodegradable
  • It is a major contributor to trash pollution across the world

b. Extruded Polystyrene Foam Board (XPS)

Many people think that EPS is styrofoam but it is not, actually XPS is styrofoam. XPS is also made up of the same material as EPS. Just like EPS, XPS is also made of 98% air and just 2% plastic.

What Type Of Insulation Is Best For Soundproofing In 2021

There are three colors available in XPS each color helps to identify the manufacturing company like Blue XPS is made by Dow Chemical, Green XPS is made by Kingspan, and Pink XPS is made by Ownes Corning and they all are the same.

The extruded polystyrene is basically a closed-cell structure, that’s why it is a good option for thermal insulation, and also it has a good R-value. Due to its closed-cell structure, it is not as effective for sound insulation as EPS is.

Pros:

  • Inexpensive than Polyiso, its 4′ x 8′ x 1″ thick sheet costs $19.98
  • R-value is 5/inch of thickness
  • Good thermal insulation
  • More moisture and mildew resistant
  • Good in wetted environments
  • The compressive strength of XPS is greater than EPS
  • No thermal drift or loss of R-value over time
  • 100% recyclable
  • Very versatile
  • Can be used below grade, below the slab, and even on basement walls

Cons:

  • It uses HFCs or hydrofluorocarbons as a blowing agent to expand the polystyrene and HFCs has a global warming potential 1300 times higher than carbon dioxide
  • The XPS insulation panels are coated in a bromine fire retardant called HBCD (hexabromocyclododecane) as like EPS which is dangerous to health.
  • XPS also attract termites and ants even though it is not an organic material
  • It is also flammable
  • Less dense than other soundproofing stuff
  • Negligible noise reduction
  • It doesn’t breakdown in sunlight and it is not biodegradable

Polyisocyanurate:

Polyisocyanurate/Polyiso is made by combining 3 main components, MDI or methylene diphenyl diisocyanate, polyol, and a blowing agent.

This foam has to be sprayed against a substrate to form a rigid panel, so all ISO panels are faced with either foil or paper.

The foil-faced panels are considered impermeable because they create an exterior barrier for vapor. They should never be used with an internal vapor barrier. If you do so then the vapors are trapped between these two barriers which can cause mold and mildew.

The Polyiso (ISO) is basically a closed-cell structure foam, that’s why it is a good option for thermal insulation, and also it has a good R-value. Due to its closed-cell structure, it is not as effective for sound insulation as EPS is.

Pros:

  • It has the highest R-value as compared to EPS and XPS, which is 6 to 6.5 per inch of thickness.
  • Polyiso is also stable over a large temperature range -100 degrees Fahrenheit to 250 degrees Fahrenheit.
  • Good thermal insulation
  • It can be used on roof systems with hot asphalt.
  • Polyiso is used on 70% of commercial roof construction
  • Polyiso also has a very low water absorption and low vapor transmission
  • It’s not affected by oil-based waterproofing compounds, insecticides, or fertilizers when it is properly protected.
  • The Polyiso industry uses pentane (C5H12) as a blowing agent which has zero global warming potential and zeroes ozone depletion potential.

Cons:

  • More expensive than EPS & XPS, its 4′ x 8′ x 1″ thick sheet costs $21.52
  • Polyiso uses halogen fire retardant TCPP which is dangerous to health
  • It doesn’t work very well in temperatures below 50 degrees Fahrenheit because the trapped gasses start to condense and they no longer act as an insulator.
  • It is the least eco-friendly option among the three.
  • Less dense than other soundproofing stuff
  • Negligible noise reduction
  • Worst thermal drift

Comparison Between The Best Top 4 Soundproofing Insulations

Here we are presenting the comparison between the best top 4 soundproofing insulation so that you could select good soundproofing insulation easily for your soundproofing project.

Denim

Cellulose

Fiberglass

Rockwool

NRC Rating

1.15

1

0.9

1.05

STC Rating

45

44

39

50

R-value/inch

3.5

3.5

2.5

3

Cost/sqft in $

1.24

1.1

0.6

1

Density lbs/ft3

3

3

1.5

2.4

From the above table, you come to know that fiberglass insulation is the cheapest among all the mentioned soundproofing stuff. Then we did the sound test and found that cellulose is a better product to reduce noise among all four products.

After all sound insulation is our first priority so you can go with cellulose insulation but remember it all depends on conditions so check your conditions and take decisions according to that.

If your conditions are not suitable for cellulose insulation then you can go with fiberglass or Rockwool insulation also.

Generally, we do not recommend Denim insulation because it is expensive, dusty, and hard to cut. But despite being expensive, we do not get the expected results. Hope you will be understanding my point.

What Factors Should We Consider Before Buying Soundproof Insulation

Some important factors we should know before buying soundproof insulation so that we could select the best soundproofing product for our soundproofing project.

We have given some factors that you should consider before buying soundproofing insulation,

✔ NRC Rating

Nrc rating indicates that how much sound an acoustic product can absorb. Nrc rating stands in between 0 to 1. The larger number indicates more sound absorption.

If the NRC rating of any acoustic product is 0.8 then it implies that 80% sound is absorbed by that product and the remaining 20% sound is reflected.

✔ STC Rating

STC is a sound transmission class which indicates that how much sound is blocked by any acoustic product. Actually, the STC rating stands between 0 to 100. The larger number indicates more sound reduction.

✔ IIC Rating

IIC rating is the measure of structure-borne noise, for example, footsteps. IIC rating indicates that how much impact noise or structure-borne noise is reduced by the acoustic product.

The IIC rating also stands between 0 to 100. The larger number indicates more sound reduction.

✔ R-value

R-value stands for thermal insulation which indicates the resistance of heat. It means a higher R-value less will be the flow of the heat.

✔ Interior/Exterior Use

Some of the soundproofing insulation is used for internal walls only so always be aware and check before buying whether it is for internal or exterior or for both purposes.

✔ Fire Retardant

Always choose the fire retardant product for your as well as your home safety point of view. Fire retardant products always resist fire up to a certain degree of Fahrenheit, it all depends upon the product which you select.

✔ Thicker, Denser, & Heavier

Thicker, denser and heavier product is always better for soundproofing insulation so always choose thicker, denser, and heavier product for better soundproofing result.

✔ Water Repellant

Check the product whether it is water repellant or not. If the product is water repellant, it means it resists the water and also protects from mold and mildew.

✔ Price

The budget is the main concern if your budget is tight then also do not go with cheap product otherwise you will come in trouble so always go with at least the good product so that you can get good results and you never feel regret.

Hope this article “What type of insulation is best for soundproofing” will help you in the right direction

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