As cozy and inviting as a successfully converted skoolie looks and feels, it's crazy to think about how they start, which is basically a long metal tube on wheels. And as any chaperone on a 5th grade field trip can tell you, there is absolutely nothing quiet about a school bus. Let’s talk about how you can identify where noise is coming from, and how to stop it.

Structural noise

Much of the noise in a skoolie comes from the structure itself. When driving along rough terrain or unkept highways at speed, the chassis and frame of a bus will rattle and shake. That coupled with the debris being kicked into and air circulating in the wheel wells, you’ve got a formula for a ruckus. The best way to reduce structural noise is to attack it at the source.

1. Wheel wells

Take a look at the wheel wells of a bus and it’s easy to see why they can create so much noise. The large wheels can kick up rocks and road debris into the wheel well which transmits sound throughout the inside. Nothing a couple layers of Spectrum sound deadener can’t fix. Brush or spray on Spectrum to fully cover the inside of the wheel well. You’ll want two to three 1mm layers to a total thickness of about 2 - 3 mm. Be sure to thoroughly clean the wheel wells and scrape away any rust with a wire brush before applying Spectrum. A liquid applied sound damping product is great for wheel wells because it is by far the easiest to install in tough to reach and tight spaces. Proper prep work is key to ensuring optimal wheel well sound deadening.

If you need to take the skoolie soundproofing a step further, you can apply Spectrum along the entirety of the undercarriage. This takes more Spectrum but will deaden the entire bottom of the vehicle, while also acting as a protective undercoating.

2. Chassis

Besides road debris, much of the noise you hear inside a bus is rattling from the metal panels that vibrate and shake as you drive along. To reduce this clanging, you can deaden the metal, which will reduce the vibrations - and you can’t have structural sound without vibrations. You could apply Spectrum again here, but we often find the Damplifier sound deadening mat is an easy-to-apply, lightweight material for these situations.

You don’t need to cover every inch of the interior with Damplifier .We typically recommend 60% coverage for any large, flat sheets of metal. You may want to do more coverage in certain areas like the front of the bus and the top of wheel wells.. Large, flat panels vibrate the most, so damping them will have a big impact and be the best bang for your buck.

Engine noise

Buses have large engines with a very high RPM to help them haul the weight of the bus and passengers inside. This powerful engine makes them very functional, but also very loud. As we’ve noted in other articles, the best way to combat airborne sound is by creating an auto sound barrier either close to the source of noise, or close to the listener. You can do both by adding soundproofing material both in the doghouse, as well as in the cabin near the driver.

Start by deadening the inside of the doghouse using Damplifier mats. You can also add Mega Block foam for even more sound deadening foam as well as insulation. We recommend our Hood Insulation Kit that contains all the materials you need for the engine compartment. Just these two easy steps will cut 3+ decibels of engine noise from the driver’s seat.

Another key spot is on the top of the engine compartment inside the bus and the cabin side firewall, where you can install Damplifier and Luxury Liner Pro. The Damplfier will deaden the metal to reduce vibrations from both the engine as well as the wind hitting the flat nose of the bus. Luxury Liner Pro is the second layer and acts as a noise barrier to block airborne noise from those same loud parts of the bus. Soundproofing a bus is in many ways like building a soundproof room - you need to seal the entire thing up (no leaks!) and increase density at all your weak points. You may not have been expecting luxury vehicle sound and heat protection in your skoolie, but with this combo you can get close!

Wind noise

We all remember which seats on the bus not to sit in during winter because the windows wouldn’t close. So it shouldn’t be a surprise that the window construction on buses is pretty poor. For any windows that you don’t need to open, seal them up with butyl tape. Not only will this help keep sound out, but it’ll also help with climate control.

Since buses were never intended to be occupied for long periods of time, let alone overnight, they aren’t inherently great at insulation. Luckily, once they’re stripped, because it’s mostly long smooth surfaces, it can be pretty easy to add your own materials. Properly insulating your skoolie will keep you cool in the summer and warm in the winter as you travel through different climates.

Effective insulation reduces heat transfer, to do this you should strive to cover as much of the inside as you can with a high R-value material and seal up any air gaps in the structure. Small air gaps throughout your skoolie can be the equivalent of leaving the door wide open. We recommend using a few materials in combination to effectively target different areas of your skoolie.

In the cockpit or driver’s area we recommend Mega Zorbe or Mega Zorbe Pro. These are hydrophobic melamine foam panels that are available in ½”, 1” or 2” thickness. They are very lightweight, Class A fire-rated, and repel water. Not only are they great for insulation, but also high performance sound absorption.

To add cost-effective insulation, try Heat Wave Pro. This is a lightweight and thin thermal, acoustic barrier made of recycled jute sandwiched between reinforced foil. So not only does it act as a heat shield, it works as a sound absorber as well. A lot of our customers use this material on the roof to reduce the radiant heat from the sun. A foil face works best with an air gap, and can add some pretty incredible insulation at a tiny thickness.

Finally, our go to insulation for any large builds is a great all-purpose material that will help with both insulation and sound absorption - the EcoVerb Roll Natural Fiber Liner. This material is a "go to" option for skoolie and van conversions, as well as being excellent for lining HVAC ducts (reduce air rush noise) or to reduce the noise level in large warehouses and other commercial spaces that need acoustic material. It’s an amazing sound absorber and insulator that is another cost-effective insulation option for your skoolie. It’s made from the same recycled cotton fibers as Heat Wave Pro, but it’s thicker and has no foil face. Just like the Heat Wave pro, it’s super light and very flexible for easy application. For more on insulation, check out our articles of van conversion insulation and van floor insulation

If you’re still reading all the way down here, you’re like us and think skoolies are pretty cool...y. Ok we’re sorry about that, we might be terrible at puns but we’re the best at soundproofing and insulation. The great thing about skoolies is that each one is unique and reflects its owner’s personality. Even though it’s a big project, part of the fun is that there’s no one-size-fits-all solution. That’s what we’re best at though – helping you figure out those hard questions. We might not be able to help you pick out the right paint swatches, but we can absolutely create a plan to make your skoolie quiet, comfortable, and ready for the road.

And we’re happy to throw our thoughts in there on the paint swatches too.