Sound Deadening in a Passenger Van

[motovan_mn]

Hello everyone,

We have an E350 with stock wagon interior (carpeted floors, wall panels, ceiling, etc). From memory the interior is much quieter than the empty cargo E350 we owned many years ago, but it is still decently louder than a normal passenger car.

I think a reduction in road/wind/engine noise would significantly improve our quality of life on long drives, so I'd like to dive into a sound deadening (and maybe thermal insulation?) project, but I was hoping to hear from some folks who have installed sound deadening on their passenger vans. I imagine the stock interior trim bits make quite a bit of difference on their own, so I'm trying to figure out if the effort of removing all the trim and installing additional deadening would be worth it.

For what it's worth, I found this thread on the Ford Transit forum, and it seems the consensus is YES. This will be a project I tackle in the spring/summer once it warms up around here, if I do decide to pursue it.

[86Scotty]

I just drove a passenger van across the country a few weeks ago. It had 2 benches in it and I didn't notice much noise except from the right side of the windshield where I have an yet to be resolved wind noise issue. As soon as I got home I pulled the benches out and was blown away at how much louder it was in there just with the benches removed! It is possible to quieten them down significantly. I'm using rigid foam under plywood floor which I will add finish flooring to at a later date. I'm also stuffing all the lower walls with Rockwool inulation (cheaper than the high dollar wool that all the #vanlife folks will tell you you must buy), available at Home Depot. For walls, wheel wells, doghouse, inside doors etc. I'm using this stuff (linked below) and so far it is totally bad ass. I'll post a video soon of the difference in door/wall noise.

https://www.amazon.com/dp/B09LQQ4KSW...roduct_details

[motovan_mn]

Originally Posted by 86Scotty

I just drove a passenger van across the country a few weeks ago. It had 2 benches in it and I didn't notice much noise except from the right side of the windshield where I have an yet to be resolved wind noise issue. As soon as I got home I pulled the benches out and was blown away at how much louder it was in there just with the benches removed! It is possible to quieten them down significantly. I'm using rigid foam under plywood floor which I will add finish flooring to at a later date. I'm also stuffing all the lower walls with Rockwool inulation (cheaper than the high dollar wool that all the #vanlife folks will tell you you must buy, available at Home Depot. For walls, wheel wells, doghouse, inside doors etc. I'm using this stuff (linked below) and so far it is totally bad ass. I'll post a video soon of the difference in door/wall noise.

https://www.amazon.com/dp/B09LQQ4KSW...roduct_details

Thanks for the quick input! Guess I have my work cut out for me...

[E-350]

You can do a 15min quick test:
Remove the door trim on the rear or barn, stuff it with any denim/ towels/ …, screw it back on and smash the door ;-)
It’s an extreme difference filled vs unfilled.

I did it 1.5 years ago and used what everyone tells you not to use: recycled denim (hydrophobic…)
Mid of the pandemic a lot of people ordered cooled/ frozen food and the companies used “green” isolation. It was for free and they have been happy not to stuff their trash bins. And as I’m in California and we don’t go snow camping I figured I don’t have a condensation issue.

In addition I took off the door trim and replaced it by simple peg board with a cheap carpet on it. This way sound is bot reflected as much and dampens as well.

[motovan_mn]

Originally Posted by E-350

You can do a 15min quick test:
Remove the door trim on the rear or barn, stuff it with any denim/ towels/ …, screw it back on and smash the door ;-)
It’s an extreme difference filled vs unfilled.

I did it 1.5 years ago and used what everyone tells you not to use: recycled denim (hydrophobic…)
Mid of the pandemic a lot of people ordered cooled/ frozen food and the companies used “green” isolation. It was for free and they have been happy not to stuff their trash bins. And as I’m in California and we don’t go snow camping I figured I don’t have a condensation issue.

In addition I took off the door trim and replaced it by simple peg board with a cheap carpet on it. This way sound is bot reflected as much and dampens as well.

Interesting, thanks. I was initially thinking of the butyl adhesive stuff you can roll onto the sheet metal, but I guess I may as well consider something that will also provide thermal insulation and kill two birds with one stone. Or maybe take the belt and suspenders approach and do both!

[1der]

You are looking to address two conditions - sound and temperature.

Sound is addressed with mass and disconnection of surfaces along with baffling (vacuum would be great but hard to achieve in our rigs, lol!)

Temperature is addressed by trapping "still" air and disconnection of surfaces. Additionally, radiation needs to be addressed.

Other considerations as you start down this path-
1. Water absorption and retention from condensation (breathing, from cooking and heating inside if stand alone propane heaters are used) and the inevitable water spills and leaks, creating potential out of sight rusting
2. Dust collection from outside
3. Degradation of insulating materials used - eg. fiberglass materials disintegrating.
4. Dissimilar metal contact between aluminized faces and steel sheet metal
5. Compression of materials when installing and when installing panels and flooring over the sound and thermal insulating materials which then negates/diminishes their effectiveness.

Finding materials that can do both sound and thermal is a challenge. Thinsulate properly installed helps address both but is not usable on the floor, only walls a ceiling.. Thermozite is similar, usable on walls and ceiling but not on floor due to water retention.

After a number of insulating efforts this is my current best advice:

Floor: POR15 or other full floor coating and a few inches up the wall. Van Bed Rug (water proof, decoupling thermal and sound plus adds baffling for only 1/2" of thickness. Adhesive weighted sound deadening on the wheel wells, foot wells, below the front seats and up the fire wall. Keep your front area factory carpet but add Thermozite under the front seat area, in foot wells, and up the fire wall as it is easy to layer and can handle the compression. If your rear area carpet is to be retained, put that over the bed rug. It is heavy, rubber backed and adds far more mass than any adhesive deadening product on the flat floor will ever add. (no adhesive deadening on the floor) If going to plywood flooring - Baltic birch 1/2" to 3/4" depending on desired height and weight. There are pros and cons to what thickness to use. The plywood adds mass. DO NOT SCREW the plywood into the van floor!(think two cups and a tight string!) This creates sound and thermal transfer paths!! If fastening of the floor absolutely needed then use the factory seat attach holes with rubber washers on both sides to minimize metal to metal contact which is what transfers sound.

Doors - patches of sound deadening adhesive material on inside face of the outer body sheet metal, maybe some on the inner sheet metal, cavity fully but not tightly filled with thermal insulation - Thinsulate works well as it provides both sound and thermal insulation. A layer of Thermozite with the fuzzy part adhesive spray attached against inner face of the body sheet metal is a good layer. Thermozite also applied w the aluminum face towards the cabin on the inside facing sheet metal can handle the compression of the trim panels.

Walls - Similar to the doors but no need for sound deadening. Use aluminum tape to seal all seams.

Ceiling - sound deadening patches between the roof ribs. Thinsulate adhered with spray adhesive. If using the factory headliner, then this is about all you can do. If no factory headliner then you can add 3/8" to 1/2" wood battens to allow for a thicker ceiling insulation layer.

Windows - largest heat loss / gain surface in a van. Window coverings that have a reflective outer facing surface tightly fitting to the window, that have an air trapping layer (coroplast or Thinsulate), and a fabric covering facing the cabin work very well. Of course, they have to be able to stowed when not in use, so folding or roll up designs work well.

Added thermal protection when camping - The front seat foot areas are cold since the firewall goes all the way up to the windshield and it is super difficult to reach all the surfaces. We are playing with adding a thermal curtain to hang down below the dash valance panels when we are camping in cold weather. We are also playing with done designs similar to the snap-on wrap around windshield curtain SMB includes with their curtain package.

Lots of time, effort, and scratched arms to do this right. Budget will be around $1k for materials. But it makes a huge improvement both sound and thermal wise. Our 7.3 diesel van is very quiet and very comfortable inside.

If you have a question about materials - test them. Tap on a material to see if it transfers or deadens sound. Use a heat gun and an infrared thermo gun to see what the heat transfer properties are from one side of the material to the other. And remember "still trapped air" is pretty much the best thermal insulator!

Hope that helps!!

[Lilnuts2]

Ray, thanks for that great info. Not only what materials but why you would use them.

[REF]

I will add a clarification to Ray’s post above. Bedrug has a product called Vantred, this is the product you want, not Vanrug.
Vantred is the full TPO rubber product that has a polypropylene foam backing, it is completely waterproof and resistant to oil and chemical spills. Unlike their Vanrug product, which is a polypropylene carpet that does not have the same waterproof, chemical or oil spill properties.
I installed the Vantred in our rig, over POR15 and strips of sound deadening material (Dynamat or similar) in the valleys, with 1/2” birch ply laid over the top of the Vantred, finished with a wood plank look sheet vinyl glued on. Solid. The nice thing is the Vantred comes in both RB and EB sizes, and is precut to fit, you can use it as a template for the plywood floor pieces.
I am planning on doing the same thing for a project van in the works, in fact Ray recently used the Vantred I had purchased for myself in his van and I ordered another.

[86Scotty]

I am using this as well in my van in certain places (link below), around the windows between the factory plastic trim (I am using some of the factory trim, not all of it). I'll also be using it under the cab area carpet.
It's a lot like Thermozite that Ray referenced above. The price is right as well.

https://www.amazon.com/dp/B09V6WN96Z...roduct_details

[Darkstar]

I put a 1/8 inch thick layer of rolled cork down first, then i covered the entire floor from the front seats back to the back doors. I then covered that with Loncoin grey rolled flooring. That has helped a great deal in keeping the road noise to a minimum in the back.