Upgrade Your Car Firewall Insulation with Sound Deadening and a Heat Shield
Author: Eric Dellolio
Last Updated: August 6, 2024
Read Time: 7 Minutes
Upgrade Your Car Firewall Insulation with Sound Deadening and a Heat Shield
Author:
Eric Dellolio
Last Updated:
August 6, 2024
Read Time:
7 Minutes
Author: Eric Dellolio
Updated: Aug. 6, 2024
Read Time: 7 Minutes
Table of Contents
- Popular Car Firewall Insulation Materials
- Get a Product Recommendation
- Why Install Car Firewall Insulation?
- Second Skin Case Study: Firewall Insulation Kit In Overland Camper
- How to Install Firewall Insulation and a Firewall Heat Shield
- Featured Product: Car Firewall Kit
- Get Help From a Second Skin Expert
Are you burning up from the engine heat in your cabin? Maybe your engine is just too loud! The automotive firewall is an important safety element in any vehicle that seems like an obvious place for factory insulation, but in most cases, all you get is a sheet of metal separating the engine compartment from the passenger compartment.
While most car enthusiasts focus on the floor and doors for sound deadening and heat insulation, the firewall is an all-too-often overlooked area where some extra effort can make a big difference in your noise and temperature control. We've got what you need!
Are you burning up from the engine heat in your cabin? Maybe your engine is just too loud! The automotive firewall is an important safety element in any vehicle that seems like an obvious place for factory insulation, but in most cases, all you get is a sheet of metal separating the engine compartment from the passenger compartment.
While most car enthusiasts focus on the floor and doors for sound deadening and heat insulation, the firewall is an all-too-often overlooked area where some extra effort can make a big difference in your noise and temperature control. We've got what you need!
NOT SURE WHAT PRODUCTS YOU NEED?
Take our quiz to find out exactly what product you need.
Why Install Car Firewall Insulation?
If you were to ride around with the windows up and your car stereo off, you’d likely hear some range of squeaks, knocks and rattles – and it’s safe to say that a fair amount of these are coming from the car engine and suspension. (And in hotrods or old classics, these noises can really be quite loud.) In the same way, you may notice your vehicle’s cabin feeling warmer than it should. Keeping your car cool on hot summer days can be a challenge.
What is a car firewall?
A car firewall is what separates the engine compartment from the cabin of the car, designed to keep engine heat out of the cabin, but it doesn't always do that well. Much like if your car is letting in cold or hot air through the roof, you add car roof thermal insulation to stop it from transferring through the roof, without an extra layer of material between you and the engine, there’s not much stopping that heat from making its way to the interior of the car.
Why does upgrading car firewall Insulation matter?
Adding an automotive heat shield and sound deadening material will bring a noticeable reduction in noise and heat. You'll have greater control over your cabin temperature for a more comfortable ride, and your stereo equipment will sound better when you remove the noise leaking in from the engine compartment.
Another key reason to add car firewall insulation is because excessive heat exposure can deteriorate wiring over time, especially if you have damaged (or entirely absent) OEM wiring insulation. Over time, the wires can stop working, short out, or even potentially start a fire in the worst-case scenario. (Yes, that was dramatic but it can happen. You can sit back down now.)
Best of all, firewall insulation and soundproofing materials are pretty inexpensive and simple to install. (The coverable area of an average firewall is small – only 10-15 square feet!) And we make it really easy, with industry-best options to accomplish your firewall insulation goals.
Second Skin Case Study: Firewall INsulation kit in Overland Camper
"I was very happy with the results of this installation. Before, the cab was loud and very warm. Excellent products and great support from Second Skin!"
- Richard M.
How to Install Firewall Insulation and a Firewall Heat Shield
The process is relatively simple: clean, measure, cut, apply. The first layer will be your sound deadening material (either Damplifier Pro™ or Spectrum™), followed by a heat shield (Mega Block™ or Thermal Block™). The goal is to cover as much of the firewall as possible with your heat shield so that you can redirect radiant heat away from the metal. Cut around screws and nails where you need to, keeping gaps to a minimum.
Steps to install firewall insulation and a firewall heat shield
The process is relatively simple: clean, measure, cut, apply.
Step One: Prepare the firewall
There are two ways to approach firewall treatments . . . well, three. You can treat the cabin-side firewall, the engine-side firewall, or both. Factors include space, comfortability, and means. If you're not sure what side you should treat, you can always give us a call at 1-800-679-8511, and we'll talk you through it.
Regardless of your choice, you'll need to have clear access to the firewall. On the cabin-side, remove any mats and carpeting in the way, and on the engine-side, you'll need to have visibility. Once you have access, clean the firewall. Whether you give it a good pressure-wash or scrub it with denatured alcohol, starting with a clean surface gives the products the best chance to fully adhere to the firewall.
Step two: measure the firewall
Measure how much square footage you're working with. If you're on the engine-side, you'll want to cover the whole thing. If you're on the cabin-side, it's worth noting that most people do not remove the dash. Take that into consideration when measuring.
Step three: apply firewall sound deadening
By adding a sound deadening layer, you're reducing heat transfer and quieting noise from entering your cabin. You have two options for sound deadening:
Option #1: Sound Deadening Mats
Our sound deadening mat, Damplifier Pro™ is our most popular product. These sound deadening mats have a base of dense elastomeric butyl rubber with a thick annealed foil constraint layer, able to conform to and form a strong bond with sheet metal and rated to 450°F – perfect for a firewall.
Installation is simple: just cut to size with a sharp razor blade, peel to reveal the built-in adhesive, and stick. 60% coverage will be plenty to deaden the metal, but we recommend 100% for a firewall to enhance thermal insulation.
Install Like a Pro
- Wear gloves when handling Damplifier Pro™.
- Always ensure 2” of clearance between the engine and any material you’re installing.
- Create a template using paper or cardboard to trace the parts of your firewall you want to cover.
- Punch holes where any screws or bolts will be.
- No air bubbles. Use a hand roller.
Option #2: Liquid Sound Deadener
Our Spectrum™ spray-on sound deadener has been a leading sound deadening solution for over a decade. This water-based, viscoelastic polymer is easy to apply, easy to clean up and engineered to perform. Essentially a sound deadening paint, it will adhere to most anything besides plastic and is perfect for those tough-to-reach parts of your vehicle (like the firewall!).
Particularly if you're thermal focused, you could apply Firewall™ Ceramic Thermal Insulation. This thermal coating is loaded with insulating glass beads to stop heat transfer through metal. It's an extremely good insulator in your engine compartment and works perfectly in tight spaces. It'll add a little deadening too, but this ceramic coating is designed to be lighter than a true deadener. As we call it Firewall... yeah, your vehicle's firewall is a good place to use it.
Install Like a Pro
- Apply Spectrum™ in layers to choose your own thickness (we recommend 3mm, in three 1mm layers).
- Cover every possible square inch of the firewall for best sound and thermal results!
Step Four: Install firewall heat shield or firewall insulation
CHOOSE YOUR TREATMENT!! Choosing a side can be a matter of ease of access or simply that there IS enough access. All materials need to have a 2" clearance from the heat source, and a lot of engine compartments just don't have enough room for it. If you're treating both sides, you'll just have to scroll . . . we're deeply sorry. Either way, we'll show you the best automotive heat insulation for the job!
Option #1: Installing a Firewall Heat Shield
Upgrade the heat shield with Mega Block™ for a superior heat barrier. Mega Block™ combines water resistant, lightweight and flexible melamine foam with a foil heat shield capable of reflecting 98% of radiant heat energy. By combining both, you get the best of both worlds with an excellent insulating layer under your aluminum reflective barrier for industry-best performance.
Thermal Block™ is our easy-to-use radiant heat barrier composed of highly reflective foil and organic fibers capable of withstanding up to 800°F and redirecting 98% of radiant heat.
We have a video of it in use on our gas tank heat shield page, showing use and ease of install.
Install Like a Pro
- If you installed Damplifier Pro™ you can use the same template or place it on your insulating material of choice, and trim that to match.
- Apply your pre-cut Mega Block™ or Thermal Block™ insulation material directly on top of the Damplifier Pro™ or Spectrum™ with the peel & stick backing.
- Face the highly reflective aluminum side toward the heat source.
- If you have a ragged edge, bind it with foil insulation tape or duct tape. We generally recommend using foil tape on all edges of your heat shield for high-heat applications.
- Always have 2" of clearance.
Option #2: Installing Cabin Side Firewall Insulation
Like we said, choosing the cabin-side approach is often because of the quality of access granted in engine compartments. A lot of engine compartments are too tight to get the material inside with enough clearance. That's why we highly recommend Luxury Liner Pro™ for cabin-side firewall insulation.
Luxury Liner Pro™ not only insulates with an R-value of 4.45, but it will also block engine noise like no other product! A noise barrier is the only way to block out that turbo or diesel noise.
Install Like a Pro
- Apply Luxury Liner Pro™ to the back of the Damplifier Pro™ with High Temp Spray Adhesive or Super Strong Double Sided Tape.
- 100% coverage is a must if you want to effectively block sound and thermally insulate your firewall. Get as far up the firewall as you can (most people do not remove the dash, though).
- Luxury Liner Pro™ is for the cabin side ONLY!
Firewall Insulation for Your Vehicle - Done Right
We're going to go out on a limb and guess that you have heat and sound coming from your engine into the cabin. Let's inch a little further out on that limb and say that you find that unwanted heat/sound somewhere between mildly annoying and downright irritating. Keep going? Alright, let's walk on out to the edge and say that you care about results.
Well... stop the train. We're at the right stop. The Second Skin Car Firewall Kit has all the materials and tools you need to make you as proud of your firewall as that parent who's kid just won the spelling bee.
- Damplifier Pro goes on first. It's heat rated to 450 F and will completely deaden your firewall to stop vibrational noise. It'll also stop some heat transfer.
- Mega Block is the second jab in your one-two punch. It's a 1000 F heat shield that reflects 98% of radiant heat and is backed by 1/2" of our high R-value hydrophobic melamine foam.
Make Sure to Celebrate a Job Well Done!
The beauty of firewall soundproofing and insulation? Aside from protecting your vehicle from excessive heat exposure, it’s a project that offers immediate gratification. Your car will be noticeably quieter, allowing you to actually take a phone call while you’re driving (or hear yourself think). And your cabin’s temperature will be much easier to control, keeping you warm in the winter (but not hot!) and cool in the summer. Nice work, friends. Enjoy the ride.