Vibration Dampening in Your Campervan

Preventing Nuisance Noise from Vibrating Panels for a Quieter Ride

There are two main reasons why noise can be a problem in a campervan:

1. The campervan itself, when in motion, can be a source of unwanted noise
2. Unwanted noise can travel through the campervan van structure whilst in motion OR stationary

This article discusses how the campervan itself, when in motion, can be the source of unwanted noise.

For the second aspect “Preventing noise from entering your van whilst in motion OR whilst stationary”, rather than sound deadening, this involves sound proofing. We discuss sound proofing your van in another article.

In most cases self-built camper vans start life as a standard panel van. Built for simply hauling
goods from one place to another. They do this job impeccably well in their cavernous haulage
compartments, with goods strapped in ensuring they reach their destination in good order.

Little consideration however is made for a comfy ride and so unlike the passenger compartment of a car, there are little to no sound deadening features added, they are simply not needed in this application and so between the goods and the outside world there is no more than a 0.9 mm sheet of metal, yikes!

It is this very sheet of metal that can be the source of unwanted noise. You see, when you are
driving along, the deviations in the road surface are transferred to your campervan via the tyres
causing it to vibrate.

These vibrations cause the air molecules around the van to crash into one another creating a
pressure wave that travels to your ear, your ear then interprets the pressure wave as sound
depending on the frequency of the material vibrating.

In our case it is a thin sheet of metal. Thin metal vibrates at a high frequency resulting in the
tinny sound that we all know and recognise when travelling for example in a budget car where
the manufacturer has scrimped on the sound deadening features.

We've all heard someone make a comment like - “Mike’s new car sounds tinny and feels so
cheap! :-(”.

In comparison, you won’t hear that coming from the passenger of a Rolls Royce. As expected, this manufacturer has the sound deadening thing covered. Passengers instead will be
contemplating the seemingly impossible silence!

It probably won’t surprise you that van manufacturers pay minimal attention to panel dampening
in the load area – they don't need to – so why would they eat into their profits?

That's why it is up to you to reduce excessive vibration of the panels, afterall you are changing
the use of the van from a carrier of goods with no feelings to a carrier of human beings that
require a comfortable environment to travel in.

Luckily for us van converters, the structure of the van – there to add strength – already helps in panel vibration control. You can see the structure of your van inside the load area. You'll notice
on the sides there's a framework running both vertically and horizontally.

This framework is usually bonded to the exterior panels (or skin) using a multipurpose construction adhesive such as Sikaflex EBT. This provides a strong bond as well as a permanent elasticity which inhibits the panel's vibration somewhat.

Our first recommendation is to check the condition of the structure-to-panel bonds on your van, if they have degraded in any way or they have in fact been omitted by the manufacturer then you can apply the adhesive yourself. You’ll need a caulking gun.

Once it has had time to cure you’ll notice a difference for sure.

TIP: It's best doing this job in warmer conditions, the EBT is much more pliable and easier to work with. If you are in a cold climate, try warming the EBT and panel with a hair dryer.

Unfortunately the structure-to-panel bonding alone is not enough to dampen the panels of your
van satisfactorily, some further intervention is required. You'll notice if you’ve ever travelled in the back of a brand new empty van, you still have that annoying tinny sound despite the framework bonding being in place.

The best way to combat the vibrations properly is to add mass to the panels to help prevent
them from vibrating in the first place. We do this by sticking dampening materials to the inside of each panel, the material is made of dense butyl compound and has a self adhesive backing for easy application.

The idea is to help stop the noise being generated at source. You’ll find a detailed step-by-step guide to adding vibration dampening material later in this article.

A word of warning, some people are tempted to cover every square centimetre of their van
interior with this stuff – whilst the manufacturers would love you to use as much as possible, it’s
just not necessary – this approach is not only very expensive, it adds a huge amount of
unnecessary weight, making your campervan slower, reducing fuel economy and adding to wear and tear on consumables such as brakes and shock absorbers.

Not all panels are equal

Not all panels need to be treated! You're just looking for the problem panels, those that resonate
the most, do the knocking test to find the worst offenders.

You’ll notice some large panels such as the roof of a van have lines pressed into the metal so
that it is no longer flat. This is called ribbing. The panels are ribbed in this way to add strength,
they also give the panel rigidity, almost eliminating the panel vibration we are trying hard to
combat. In our opinion no further sound deadening treatment is required for ribbed panels.

Step-by-step guide to applying sound deadening, vibration dampening material to your campervan

What you’ll need:

• Vibration dampening material
• Roller
• Utility Knife
• Cutting Board
• Gloves
• Sikaflex EBT
• Caulking Gun

Here’s how to do it:

1. Carry out a knock test to determine the panels you will be dampening.

   You don’t need to worry about ribbed panels, the ribs dampen these panels enough and no further treatment is required. Here is an example of a ribbed roof of a van.

2. Roll your vibration dampening material out flat.

3. Mark along the longest edges intervals of 20cm, using a permanent marker

4. Run a straight metal edge between the marks on either edge and cut using a utility knife, take care!

5. You will now have a number of strips, cut each of these strips in half so you are left with manageable portions ready for application

6. Remove the self adhesive backing from a portion

7. Apply to the centre of the panel you are dampening

8. Apply firm pressure using a roller to evenly bond the material to the panel

9. Repeat steps 6 to 9 for each panel you are dampening. JOB DONE!

Being van converters ourselves, you can rest assured we have personally tried and tested all the products we recommend. The products that make it to our ‘What you’ll need’ lists are the best of the many different brands we have painstakingly tried.