Sound proofing and van insulation in a camper conversion

TLDR: Second skin butyl, luxury MLV, and aerofoam for sound proofing, followed by sheep’s wool, except for the flooring and doors which are Thinsulate and minicell for van insulation.

Sound proofing was something really important to me. I did a lot of research and found that total surface coverage didn’t necessarily provide a lot more benefit relative to the cost and weight – about 35-50% coverage will give great results.

What is sound proofing? Well, there’s a few types. First, there’s sound dampening. This is a heavy material that dampens the vibrations of the surface it’s attached to – thin rattling metal for example. Then, there’s actual sound proofing – a material that blocks sound from getting in or out. In other words, it reflects sound back to you and prevents sound from entering.

Having spent noisy nights at busy summer campgrounds, and sleeping near traffic and trains, sound proofing and van insulation was non-negotiable. I wanted to be able to run my blender without waking anyone at 5am. I wanted to have sex and listen to music and not have to worry about neighbors hearing. Getting a full night’s sleep was an absolute top priority, and I’m a very light sleeper.

Applying the sound deadening and proofing materials was a lot of work. Not hard – just time consuming. You’ll need a few tools to cut and score the butyl mats, plus a roller to make sure the contact is secure. The basic steps are to first apply the

How much of these supplies will depend on your van size. What I’ve listed above is for a high roof, 148″ extended Ford Transit. If your van is larger or smaller, adjust the sq footage you wish to cover appropriately.

Step 1: Clean and apply damplifier (butyl sheets)

Start by cleaning your metal with rubbing alcohol and let dry. Dust or oil will prevent the butyl from properly adhering.
The entire van does not need to be comprehensively covered. 30% – 60% will provide most of the benefits without adding a ton of extra weight or labor. Checkerboard placement of the butyl slices has the most ROI for partial coverage. The most important parts to cover are the wheel wells – I covered these almost completely – and the large thin metal areas such as the walls. The doors are a thicker metal and won’t vibrate as noisily, so if you are trying to save money and energy focus on the wheel wells and as much as you can afford to cover on the walls.
Using a box cutter with a fresh blade – I like to change blades every 5 or so cuts – cut pieces to cover the areas. Use a heavy metal roller to help completely flatten the butyl on the metal.

Step 2: Cut and tape luxury liner (sound blocking) atop butyl

Use the box cutter to cut pieces of the luxury liner to fit the butyl pieces you previously attached. Apply the heavy duty double sided tape in an “X” or multiple lines to get a secure attachment. I recommend pieces not larger than 1-2′ per side, as the weight may be a bit too much with the van vibrations. I tried to cover a whole rear “window” area and it was far too heavy for the tape.

Step 3: Ceiling

The roof I did a bit different from the rest – I started out with a layer of this ultra lightweight hydrophobic melamine foam from Second Skin. It was sooo easy to apply to the ceiling and offered immediate insulating and acoustic improvements. When I first got the van it was in the summer, and the simple addition of sound dampeners, proofing, and these panels on the roof made the van noticeably quiet and cooler in the middle of a warm southern california summer. It took less than 30 minutes to apply. While I’m not sure it provides much warmth in winter, I’m very happy with how much it cooled down the van on it’s own.

Step 4: Insulation

TLDR: Sheep’s wool in the walls + ceiling, Thinsulate in the floors and doors

And what about insulation? There’s a lot of controversy out there on which to choose. I loved the idea of sheep’s wool, but there are a few naysayers who say if it gets wet it will be awful. For this reason, I kept wool to the walls and ceiling, and not the floor. 1 plumbing leak or major spill, and one tiny uncaulked corner of the floor will have you crying. And we had one! I’m really glad that I didn’t user Havelock wool insulation for the floor, and I’m very glad I used it for the walls and ceiling.

As far as roof leaks go, make sure to seal any potential openings – such as ALL the factory entry points on the roof. Before you go camping with any chance of rain! So far, so good since I’ve done this. And early in the build we did have one – it was the tiniest, almost imperceptible crack, but it was enough for rain to get through. This was before we added the walls and van insulation, so we caught it early and I learned the lesson before it became a problem.

Other types of van insulation have harsh chemicals, like the pink synthetic stuff. I don’t want to go into great detail here, because lots of other have written about it ad nauseum. However, my second choice would have been Thinsulate – which is what is in the floor. I’m happy with it for flooring, but there’s a lot of space between the metal walls of the van and the siding, and I was skeptical about how much warmth it provides. Also, wool is known for it’s acoustics-improving properties, and is often used to improve the sound in rooms and buildings. So, given how important a quiet inside of the van was, it was a no brainer for us.

After I added the roof studs and attaching my 1/4″ cedar planks bit by bit – I began stuffing the Havelock wool insulation batts between the airspace of the planks and the studs. It was a perfect amount of space for 1 layer of batting.

Combining sound proofing and insulation in a van conversion will result in a quiet, cozy van that is warm in the winter and cool in the summer. So far we’ve tested ours into the 20s, and we do a lot of loud things in the van at 5am and not a peep can be heard outside.