The Complete Guide to Automotive Insulation

The Ultimate Car Insulation Guide

What you need to know before starting a car soundproofing project or installing auto insulation material

Car Insulation: Let's Start at the Beginning

All cars need insulation. All cars have insulation, although the amount and quality depends on the vehicle’s make and model. If you’ve found your way to this guide, we’d be willing to bet that your car has a problem. Maybe you have too much noise in the cabin, which could mean unwanted road noise or an audio system that’s not delivering the type of sound you paid for. Maybe you have too much heat, because that sports car just isn't as fun to drive when it's cooking your feet. Whether you’re dealing with noise or heat, we have the insulation options to help you put those problems in the rear view mirror (sorry, bad pun), and get back to enjoying your ride.

If you’re like us, when you do a thing you want it done right. But how do you decide if a thing is even worth doing in the first place? It's hard to rationalize paying for something you don’t understand. Because we spend so much time in our vehicles, soundproofing a car is one of those things that can pay big dividends to your quality of life. Ironically though, it's also the kind of thing that when done right you won't see it or hear it. It's like the time you finally decided to splurge on a bed because you spend 1/3 of your life in it. You didn't even know what you were missing until you upgraded.

Like with many things in life, automotive sound insulation is one area in which it pays to be strategic and work smarter, not harder. There is no cure-all to create the vehicle of your dreams, and you should be wary of anyone trying to sell you one (it’s more likely a cure-none). If you approach car insulation the right way, it’s a three step process to turn any vehicle into a luxury car. The more you know, the more cost-effective you can be and the better results you’ll get when soundproofing your car.

Understanding the Noise in Your Car

Cure-alls treat every type of noise the same, but in reality, there are two types of noise you’ll experience in a car:

Structural Noise: created by your vehicles moving parts (vibrations, rattles, etc)

Structural Noise: created by your vehicles moving parts (vibrations, rattles, etc)

Airborne Noise: sound waves that penetrate your car's cabin from the outside air

Airborne Noise: sound waves that penetrate your car's cabin from the outside air

Once we uncover the source of your noise problem, we can determine the best method for stopping it. There are three noise-cancelling methods, each with its role to play:

Sound Deadening: reduces noise by stopping vibrations and rattles (structural noise)

Sound Deadening: reduces noise by stopping vibrations and rattles (structural noise)

Sound Blocking: prevents noise from entering your car (best for airborne noise)

Sound Blocking: prevents noise from entering your car (best for airborne noise)

Sound Absorbing: stops the noises already inside the car cabin from bouncing around the interior

Sound Absorbing: stops the noises already inside the car cabin from bouncing around the interior

Depending on your vehicle and your goals, you may just need a little help in one of these areas or you may be thinking about a full-on interior rebuild. Wherever you find yourself on that continuum, we have the tools and the know-how to help you achieve your car soundproofing goals!

The Best Car Sound Deadening Materials

If you’re restoring a classic car, fixing up an old work truck, or driving a vehicle that naturally creates a lot of sound, you need to deaden that metal. Over 20 years of testing, we’ve found the best materials for automotive sound deadening to be:

  • Butyl rubber: an odorless, synthetic rubber which we enhance with increased elastomeric properties. Butyl rubber is tough; it’s what holds the air in your tires.
  • Viscoelastic acrylic polymer: Liquid material highly effective in reducing vibrations. Viscoelastic materials are such an effective shock absorber that at one point, one was wrapped around the Liberty Bell to protect it from further cracking.

Second Skin has proprietary formulas for both our sound deadening mat and liquid deadener products, and is the only American made manufacturer currently offering high quality options for both types of deadening.

Damplifier Pro Deadening Mats

Second Skin's signature 2mm thick constraint layer damper (CLD). High-temperature butyl rubber adhesive mats engineered for performance

Great for:

Best-in-Class Sound Deadening

No Asphalt or Cheap Fillers

450℉ Heat Rating


Damplifier Deadening Mats

Second Skin's lightweight CLD mats. Made of the same high-quality materials as Damplifier Pro

Great for:

Lightweight Sound Deadening

Half the Weight per Square Foot

450℉ Heat Rating

  • Comparison Chart
  • Install Locations
Damplifier Pro Damplifier

Total Thickness

2mm (80mil)

1mm (40mil)

Foil Constraint Layer

black, annealed foil

black, annealed foil

Weight per Square Foot

0.70 lbs

0.35 lbs

Sheet Size

12" x 20"

12" x 24"

Cheap fillers?

Never!

Never!

Awesome?

Yes!

Yes!

Damplifier Pro and Damplifier are designed to do the same job, but Damplifier Pro has twice the butyl rubber. The primary differences are:

  1. Performance: Damplifier Pro deadens metal 30-50% better, depending on the application.
  2. Weight: Damplifier weighs about half as much per square foot.

Automotive

  • Doors (outer and inner door skins)
  • Floor
  • Firewall on cabin or engine side
  • Trunk floor, walls, and lid
  • Roof
  • Hood (entire lid)

Residential/Commercial

  • Generator boxes
  • Screen doors
  • Dishwasher enclosures
  • Sink tubs
  • HVAC ducts
  • Warehouse and hospital carts
  • Comparison Chart
  • Install Locations
Damplifier Pro Damplifier

Total Thickness

2mm (80mil)

1mm (40mil)

Foil Constraint Layer

black, annealed foil

black, annealed foil

Weight per Sq Ft

0.70 lbs

0.35 lbs

Sheet Size

12" x 20"

12" x 24"

Cheap fillers?

Never!

Never!

Awesome?

Yes!

Yes!

Damplifier Pro and Damplifier are designed to do the same job, but Damplifier Pro has twice the butyl rubber. The primary differences are:

  1. Performance: Damplifier Pro deadens metal 30-50% better, depending on the application.
  2. Weight: Damplifier weighs about half as much per square foot.

Automotive

  • Doors (outer and inner door skins)
  • Floor
  • Firewall on cabin or engine side
  • Trunk floor, walls, and lid
  • Roof
  • Hood (entire lid)

Residential/Commercial

  • Generator boxes
  • Screen doors
  • Dishwasher enclosures
  • Sink tubs
  • HVAC ducts
  • Warehouse and hospital carts

Spectrum Liquid Deadening Spray

Second Skin's high heat, water based viscoelastic deadener goes on easy and can be applied thicker to increase dampening

Great for:

Liquid Sound Deadener

Adheres to Most Surfaces

400℉ Heat Rating

  • Comparison Chart
  • Install Locations
Spectrum Liquid Spectrum Sludge

Total Thickness

2-5mm (1mm per layer)

2-5mm (1mm per layer)

Square Feet / Gallon

20 Sq Ft at 2mm thick

20 Sq Ft at 2mm thick

Weight / Gallon (dry)

7 to 9 lbs

7 to 9 lbs

Color

Blue (wet), Black (dry)

Blue (wet), Black (dry)

Consistency

Chocolate syrup

Peanut butter

Application Method

Brush, roller, spray gun

Brush, trowel, gloved hand

Activator Required

No

Yes

Spectrum can be ordered with an optional activator. Stirring in the activating liquid will change its consistency while maintaining its excellent viscoelastic properties.

Automotive

  • Doors (outer and inner door skins)
  • Floor
  • Firewall on cabin or engine side
  • Trunk floor, walls, and lid
  • Roof
  • Hood (entire lid)
  • Undercarriage
  • Wheel wells
  • Comparison Chart
  • Install Locations
Spectrum Liquid Spectrum Sludge

Total Thickness

2-5mm (1mm per layer)

2-5mm (1mm per layer)

Square Feet / Gallon

20 Sq Ft at 2mm thick

20 Sq Ft at 2mm thick

Weight / Gallon (dry)

7 to 9 lbs

7 to 9 lbs

Color

Blue (wet), Black (dry)

Blue (wet), Black (dry)

Consistency

Chocolate syrup

Peanut butter

Application Method

Brush, roller, spray gun

Brush, trowel, gloved hand

Activator Required

No

Yes

Spectrum can be ordered with an optional activator. Stirring in the activating liquid will change its consistency while maintaining its excellent viscoelastic properties.

Automotive

  • Doors (outer and inner door skins)
  • Floor
  • Firewall on cabin or engine side
  • Trunk floor, walls, and lid
  • Roof
  • Hood (entire lid)
  • Undercarriage
  • Wheel wells

Sound Deadening Wrap Up

Not sure which deadening option is best for you? We get it, which is why we wrote a whole article comparing sound deadening spray vs mat vibration dampers. Feel free to take a detour.

The Best Sound Blocking Materials for your Car

If you feel like your car makes an incredible amount of road or tire noise, you’re likely in need of a noise barrier to keep those roaring noises outside of your vehicle. We use sound blocking materials to create a barrier layer that acts as a wall between you and the noise, effectively turning your car into a soundproof booth. To get the best results, you need to first apply a sound deadening product to reduce the amount of noise your car is creating, and then add the sound blocking layer to create a barrier to stop the noise coming up through the floor and the bottom of the doors.

The best material for automotive sound blocking is mass-loaded vinyl, or MLV. Any good sound blocker needs to be dense, limp, and flexible enough to contour to the curves of your car - allowing you to create as close to an unbroken barrier layer as possible. We have two high quality, American-made options for mass loaded vinyl.

Luxury Liner Pro - MLV + Closed Cell Foam

Second Skin's best noise blocker. By fusing the MLV to a decoupling layer of closed cell foam, Luxury Liner Pro saves you time on the install and has our best STC rating

Great for:

MLV Sound Barrier

Dense and Flexible

Bonded Decoupling Layer


Luxury Liner Mass Loaded Vinyl

Second Skin's premium mass loaded vinyl for when a decoupling layer isn't needed or you want to customize your own noise barrier

Great for:

MLV Sound Barrier

Dense and Flexible

Residential Use

  • Comparison Chart
  • Install Locations
Luxury Liner Pro Luxury Liner

Total Thickness

3/8" thick

1/8" thick

Composition

MLV + Foam

MLV Only

Size / Sheet

24" x 54"

24" x 54" or a Full Roll

Weight per Sq Ft

1.25 lbs

1 lb

Color

Black

Black

STC Rating

28

26

Road Noise

Dominated!

Destroyed!

Automotive

  • Doors (between door skin and panel)
  • Floor
  • Firewall on cabin side
  • Trunk floor, walls, and over the wheel wells

Residential (Luxury Liner only)

  • Walls
  • Floors
  • Ceilings
  • Recording studios
  • Music rooms
  • Home theaters

Luxury Liner Pro is two materials bonded together, whereas Luxury Liner is just MLV.

The Best Sound Absorbing Materials for Your Car

The final touch to eliminate unwanted noise in your car is installing sound insulation foam or jute. With the right products installed, echoes and irritating noise interference will be a thing of the past. One of the advantages of sound absorbers is that they’re so versatile — the best also act as reliable decouplers and heat insulators.

Second Skin only uses the finest foams and jutes in our sound absorbing automotive insulation products.

  • Melamine foam - Used globally in pipe insulation and auditorium soundproofing. The hydrophobic melamine foam (HMF) is particularly useful in cars, as it is waterproof and has a high resistance to heat. HMF is generally accepted as the highest quality solution for sound absorption in vehicles.
  • Jute - Jute is a natural fiber often spun into thick layers of matting used for sound absorption. High-quality jute sound absorbing materials are plush and great natural insulators.
  • Closed-cell foam - Unlike open cell foam, closed cell foam is impermeable and doesn’t transfer air or water, making it an excellent insulator. Closed cell foam is most effective when used as a decoupler between hard surfaces like rattling plastic panels.

Mega Zorbe Hydrophobic Melamine Foam

Second Skin's best sound absorber and thermal insulator. Mega Zorbe melamine foam has undergone a patented hydrophobic treatment to make it safe for use in vehicles.

Great for:

Foam Sound Absorber

Peel & Stick Option

Aerospace Grade


Heat Wave Pro - Jute + Reflective Foil

Second Skin's all-around utility player will add improve any vehicle. Heat Wave Pro is lightweight, a good sound absorber, an excellent insulator, and includes a reflective radiant barrier.

Great for:

Jute Sound Absorber

Recycled, Treated Denim

97% Reflectivity

  • Comparison Chart
  • Install Locations
Mega Zorbe Heat Wave Pro

Total Thickness

1/2" thick

3/8" thick

Composition

Open Cell, Melamine Foam

Jute + Foil Barrier

Size / Sheet

24" x 48"

4ft x 6ft

Weight per Square Foot

It's basically air!

0.19 lbs

Max Temperature

350℉

250℉

Fire Rating

Class A

Class A

R-Value

2.08

1.47

Special Superpower

Hydrophobic

97% Reflective Foil Barrier

Mega Zorbe

  • Doors (outer door skins)
  • Roof above the headliner
  • Trunk lid
  • Premium option for a sprinter van, camper van, or RV

Heat Wave Pro

  • Floor
  • Firewall on cabin side
  • Trunk floor, walls, and lid
  • Roof above the headliner
  • Hood (entire lid)
  • Economical option for a sprinter van, camper van, or RV
  • Comparison Chart
  • Install Locations
Mega Zorbe Heat Wave Pro

Total Thickness

1/2" thick

3/8" thick

Composition

Open Cell, Melamine Foam

Jute + Foil Barrier

Size / Sheet

24" x 48"

4ft x 6ft

Weight per Square Foot

It's basically air!

0.19 lbs

Max Temperature

350℉

250℉

Fire Rating

Class A

Class A

R-Value

2.08

1.47

Special Superpower

Hydrophobic

97% Reflective Foil Barrier

Mega Zorbe

  • Doors (outer door skins)
  • Roof above the headliner
  • Trunk lid
  • Premium option for a sprinter van, camper van, or RV

Heat Wave Pro

  • Floor
  • Firewall on cabin side
  • Trunk floor, walls, and lid
  • Roof above the headliner
  • Hood (entire lid)
  • Economical option for a sprinter van, camper van, or RV

Let's Stop Here and Talk about Decoupling

Decoupling is one of the secrets of automotive insulation gurus. All a decoupler does is separate two materials from each other so that they transfer less energy. Less energy passing through means less vibrations, less rattles, and less noise.

Any hard surfaces in your vehicle can be decoupled. The most common areas we see a decoupler used is behind noisy plastic panels. Squeeze your decoupling layer into the gap to act as a shock absorber and prevent the panels from rattling.

The added benefit of using a decoupler is you're also adding additional car insulation at the same time. Heat Wave Pro is an excellent decoupler and insulator. We also offer a line of decoupling closed cell foams that are very durable and will further insulate your vehicle. We call them OverKill.

OverKill Pro Closed Cell Foam

Second Skin's thickest closed cell foam decoupler and insulator. OverKIll Pro is flexible, durable, waterproof, and perfect for rattling panels or noise distortion inside door panels

Great for:

Decoupling Sound Absorber

Durable Insulation


OverKill Closed Cell Foam

Second Skin's thinner closed cell foam is thin enough to fit into the tightest cavities of your vehicle. OverKill decoupling car insulation is ideal for door panels and other tight plastic paneling

Great for:

Decoupling Sound Absorber

Durable Insulation

Waterproof

  • Comparison Chart
  • Install Locations
OverKill Pro OverKill

Total Thickness

3/8" thick

1/8" thick

Composition

Closed Cell Foam

Closed Cell Foam

Size / Sheet

24" x 54"

24" x 54"

Weight per Square Foot

0.38 lbs

0.125 lbs

Heat Resistance

165℉

165℉

Water Resistance

High

High

Automotive

  • Decouple any plastic paneling
  • Doors (inner and outer door skins)
  • Floor, firewall, and trunk (underneath MLV)
  • Roof (above the headliner)

OverKill Pro is 3x as thick as the standard OverKill

The Best Heat Insulation Materials for Your Car

Every car needs heat insulation. Depending on the goals of your automotive insulation project, there are two materials to consider: insulators and radiant barriers. Effectively utilizing these heat barriers will solve two problems at once.

  1. Controlling the climate inside your vehicle
  2. Managing heat-related issues under the hood

Our automotive thermal insulation uses several different types of materials.

  • Highly-reflective aluminum foil — we use reinforced aluminum foil to reflect radiant heat and protect the layer of insulation within.
  • Melamine foam — its natural resistance to heat makes it the perfect material to increase insulation in your vehicle
  • Thermal acoustic jute — We pair this treated, heat resistant insulator with a durable foil to both insulate and reflect radiant heat.

Sound absorption and heat insulation go hand-in-hand. Although not all materials and products do both, Mega Zorbe and Heat Wave Pro are excellent at both sound and heat insulation. That's why they are our most popular car insulation solutions.

We also offer two different options for radiant barriers, depending on your vehicle's needs.

Mega Block Foam + Foil Reflector

Second Skin's highest quality radiant heat barrier. Mega Block's combination of hydrophobic melamine foam and aluminum-foil faced composite is perfect for any hood or firewall project

Great for:

Radiant Barrier

Face Foil to Heat Source

1000℉ Heat Rating


Thermal Block Radiant Heat Reflector

Second Skin's highly reflective foil radiant barrier combines with organic fibers to redirect heat and keep your car cabin cool

Great for:

Radiant Barrier

Face Foil to Heat Source

800℉ Heat Rating

  • Comparison Chart
  • Install Locations
Mega Block Thermal Block

Total Thickness

1/2" thick

1/4" thick

Size / Sheet

24" x 48"

24" x 36"

Weight / Square Foot

0.22 lbs

0.175 lbs

Max Temperature

1000℉

800℉

Radiant Heat Reflectivity

98%

98%

Automotive

  • Firewall (engine side)
  • Hood (entire lid)
  • Back seat wall, if engine in the rear

Apply anywhere there is a heat source, facing the heat.

Ready to Get Started?

Once you’re able to determine what kind of noise you’re experiencing in your car and which noise-cancellation method you need to use to eliminate it, all that’s left is to find a great product and get started. Second Skin has you covered with every product you need to complete your automotive insulation project. Check out our online inventory and make it happen today!

Dive Deeper into Car Soundproofing Strategies