Car Roof Insulation

Upgrade Your Car Roof Heat Insulation

How To Install Trunk Sound Deadening

Think about the last time you drove around during a torrential downpour. How loud was it in your vehicle? And where was the majority of the noise coming from? Odds are, it was the roof. The noise varies a fair amount between vehicles, but the roof can be a very resonant panel – and it doesn’t help matters that it’s the sheet metal closest to your head. Read on to learn about roof insulation options that can cut down on the noise – and keep the interior temperature just the way you like it.

Driving is as much an experience as it is a necessity. You should enjoy how your ride feels, how it looks, and even how it sounds. That last piece can be a challenge, because cars come with a fair share of noise, from structural hums, rattles and squeaks to airborne sounds like wind, road noise and horn honking.

Fortunately there are some great products to improve your driving experience (and they don’t involve earplugs). They’re called vibration dampers and a question we hear all the time is, do you go with the mats or with a sound deadening spray?

Car Roof Insulation 101

Mega Zorbe used as car roof insulatio

A Second Skin customer's sprinter van roof lined with Mega Zorbe, our best automotive insulator.

The Headliner

The term headliner refers to the layers covering the ceiling of your vehicle’s interior. A knit fabric layer covers a foam-like layer of polyurethane that adheres to the fiberglass roof. This entire unit is the headliner, and it keeps the temperature comfortable inside the car while also providing a degree of sound deadening. However, outside of luxury vehicles, this standard layer of polyurethane in most cars is usually minimal, leaving significant room for improvement.

Benefits to Upgrading Roof Insulation

Upgrading your roof insulation will create a noticeably quieter drive, particularly where wind noise, rain and other weather-related noise is concerned. You may also notice improved performance of your audio system, with added insulation virtually eliminating exterior sounds and improving the clarity of the music. Some customers even find themselves turning the volume down since airborne noise is less of an an issue! Climate benefits are big as well, with many noticing improved air conditioning, as additional headliner insulation prevents cool air from escaping the vehicle.  

Second Skin's Car Roof and Headliner Insulation

For car roof soundproofing and car roof thermal insulation, it’s key to start with the right materials. The most effective sound deadeners are made with a base of some sort of rubber – Second Skin uses butyl rubber paired with an aluminum constraint layer for mats and a water-based viscoelastic polymer for liquids and sprays. (Never asphalt!) For heat insulation, you want a material with a high R-value, which is the material’s capacity to resist heat flow. At Second Skin, we like to use lightweight, high R-value materials that are thin enough to fit behind your car’s upholstery and panels.

Car Roof Soundproofing Materials

If sound deadening is your whole agenda, go with Damplifier Pro™ mats or Spectrum™ spray-on sound deadener. Both are applied directly to metal and act as a shock absorber to resist the energy of the vibrations, thus “deadening” a lot of the noise. Damplifier Pro™ Sound Deadening Mats are 2mm of American-made butyl rubber and a thick, annealed foil. Spectrum™ is a water-based, viscoelastic polymer that’s easy to apply, easy to clean and engineered to perform.


Cut Damplifier Pro™ with a sharp razor blade to get clean, precise lines. For Heat Wave Pro™, use serrated scissors (a razor blade will pull on the denim fibers).

Car Roof Thermal Insulation Materials

To greatly increase the amount of insulation above the headliner, consider Heat Wave Pro™ or Mega Zorbe™. Heat Wave Pro™ is an excellent thermal insulator made of recycled jute, while Mega Zorbe™, our hydrophobic melamine foam, is an industry-leading combination of thermal and sound insulation. This aerospace approved foam is ideal when you have a bit of space to work with between your car roof and the headliner. You don’t want to squish Mega Zorbe™ due to the open-cell structure. If you’re limited to less than half an inch, we recommend sticking with the Heat Wave Pro™.

How to Install Your Car Roof Sound Deadening and Insulation

Step 1: Remove The Headliner

The first step in removing the headliner is to remove all attachments, like grab handles, seatbelt heads and brake light covers. Next you’ll remove the trim pad panels that run along the sides of the headliner. This will release the headliner from the roof of your car, at which point you can simply pull it out.


Take notes and/or photos of your car’s headliner as you remove it. The reference will help you reinstall the headliner correctly when you're done putting in your new insulation.

Step 2: Install Car Roof Sound Deadening

We recommend 100% sound deadening material coverage of your car roof for optimal results. While you only need to cover 60% to properly deaden the roof, that extra 40% of coverage is going to give you much needed thermal insulation for when it's really hot or cold.

Your sound-deadening product (Damplifier Pro™ or Spectrum™) should be applied first as your vibration reduction layer. Damplifier Pro™ comes in sheets that you can cut to size with a sharp utility knife for easy application. Installation is fairly simple – just cut to size, peel to reveal the built-in adhesive, and stick. Most people get a wooden hand roller to roll the sound deadening mat onto the metal sheet and ensure a firm bond.

To apply Spectrum™ spray-on sound deadener, we recommend using a spray gun to get an even coat across the board, although some folks prefer to simply paint it on with a brush. Spectrum should be applied in 1mm layers to ensure proper adhesion. For most situations, we recommend to do 2mm total, but some customers choose to continue layering Spectrum on to continue increasing their results. We don't recommend doing more than 5mm.

INSTALLATION TIP: Your average car roof is 20-25 sqft. But like Mom always said… Measure twice, cut once! Thanks Mom.

Step 3: Add Thermal Insulation As Your Next Layer

The thermal insulation product (Heat Wave Pro™ or Mega Zorbe™) will go on next as the heat barrier layer. Make sure to fully attach the barrier layer with spray adhesive or double-sided tape. Don’t skimp! Cover all areas of the roof, as this application will fight gravity, heat and movement on a daily basis. Tape the seams and edges to protect them from daily wear and tear.

If you decide to use Mega Zorbe™, make sure you have at least a half-inch of clearance, as it’s an open-cell foam and needs to be fluffed out in order to be effective. After the vibration and heat barrier layers have been applied, you may reapply the factory foam material IF you have extra clearance. With insulation, more is almost always better.


Don't throw out the factory car insulation (unless it's gross or completely worn out)! Save it in case you still have room above the headliner when you complete your install. Extra layers will increase the total r-value and further reduce heat transfer!

Second Skin Makes Awesome Car Roof Kits

If you’re looking for the quickest and easiest way to get maximum results, consider a Second Skin Audio Car Roof Kit. It's easy to toggle between the various options discussed in this article, and each kit combines exactly what you need to get the job done (with a 10% discount included!). Aside from the soundproofing and thermal insulation materials, each kit also includes any needed adhesives and tools to make the job easier.

Go with the Standard Roof Kit for a combo of Damplifier Pro™and Heat Wave Pro™, or upgrade to the Premium Roof Kit for Damplifier Pro™and Mega Zorbe™.

Think About Putting a Better Roof Over Your Head

The bottom line is that it’s no good for road noise to take away from the expensive sound system you installed, or for rattling or whistling sounds to keep you from taking a conference call on speakerphone. The same goes for your car’s climate: it needs to keep you warm in the winter and cool on those stifling summer days. The right insulating products will help you find that sweet spot – it’s just a matter of choosing which ones to use. If you have questions or want to discuss your options, reach out to us any time – we’re here to help.

For a fully quiet ride, incorporate soundproofing and thermal insulation on your vehicle's floor, door panels, trunk, and hood as well. We literally wrote the book on it.