DIY Insulation - What's the standard these days?

[birdman86]

With the new van I'm trying to figure out what to do for insulation, and there's tons of different setups over the years, and a whole lot of warnings about moisture. What's are people using these days? My most likely max temperature range would be -25C to +35C, or say -15 to 90F. It's an '03 van with super low KM's so the last thing I want is a setup that will promote rust - therefore the moisture situation is my biggest concern.

Right now I'm planning on (starting at the van wall and working in). This will all end right behind the cab, so that up front is basically untouched other than dynamat:

1) Dynamat on the bare steel for sound dampening only (already have this, so might as well use it)
2) Fill the ribs with that expanding foam in a can
3) Cover every square inch of the cargo area with Reflectix and foil tape, goal being to form a vapor barrier between the living area and steel body.
4 - Walls) Some kind of fill insulation (this is where I get stuck). From what I understand, I need something that will not absorb moisture, will not emit gasses, will not settle, will offer some sound absorption qualities, will not irritate, and yet will be warm enough to hold the heat in on those -25C nights at the ski hill. Quite the wish list...
4 - Roof & Floor) Rigid insulation, like Durafoam
5) No vapor barrier as the reflectix on the other side of the insulation should be good enough
6) Any wiring/etc would be at this layer
7 - Roof and Walls) Paneling of some sort, I'm thinking wrapped in that speaker box carpet stuff
7 - Floor) Maybe a thing layer of rubber (gym mat or something) to smooth everything out, and plywood on top of that, followed by flooring of choice (laminate or something)

Questions
- I'm considering replacing the reflectix with foil sided duct wrap as I hear reflectix needs an air gap while the duct wrap has bubbles that act as that. Is there any benefit that I'd be sacrificing for this? The plan is to have whatever I use right up against the wall as I'm not sure how to put a reliable gap in otherwise.
- Would #2 be a bad idea? Are there drainage holes in the ribs to worry about, or are they useful for running wires and stuff? Is there any reason to not fill them with something like Great Stuff Big Gap Filler?
- Would #3 be a sufficient vapor barrier to protect against rusting the van out? Should I leave a gap at the bottom so moisture doesn't pool anywhere?
- What product should I use for #4? One website had a pretty solid argument for foil backed jute, but I can't find that online anywhere (lowes.ca, homedepot.ca, etc). Would the foil backing be unneccessary given the reflectix layer? Homedepot.ca only seems to have Rock wool or pink fiberglass, both of which I've read you don't want to use.
- #4 again - Is 3M Thinsulate a top choice? I don't know where I'd find it locally, but I'm willing to pay a small premium for peace of mind and warmth.
- As long as the fill insulation doesn't absorb moisture, I'll be fine with no vapor barrier on the inside correct?
- Is there anything I should be aware of for flooring? Do I want to leave a gap around the perimeter for drainage? Should the wall panels and insulation sit on top of the floor, or should the floor end just inside of the wall setup?

Any tips much appreciated...!

 

[Treenail]

Birdman,

I'm grateful that you posted these questions. They have been kicking around my head too.

My approach is based on two different perspectives. First, a camper van with a metal shell that doesn't breath. Second, many weeks of winter camping where moisture management is the key to comfort.

Insulation slows heat loss and sets up layers where the water vapor will condense turning into water. Gotta vent that...open pit zips...take off a hat...for clothing...easy....for a van...not!

If the warm air is allowed to escape from your warm van the moisture will condense...leading to rust on the van and damp clothes...you know all about that since you're skiing.

Look into a Fantastic Fan or some other forced air vent.

When it comes time to camperize my '05 Safari AWD window van I'm looking hard at 3M Thinsulate...after all, I am from MN! And Thinsulate is in a lot of my winter gear.

I'll lay down some sort of closed cell foam/rubber matt under plywood for the floor. Painted on both sides. Wall insulation will meet the flooring and be sealed to make a vapor barrier inside.

Now...what do others say?

Tom

 

[boardrider247]

Your vapor barrier should be on the "wet" side of your insulation
From my perspective your order should go like this from van to interior
Sound deadener-insulation-vapor barrier-finish
This keeps your insulation dry rather then allowing it to absorb moisture before the moisture gets to your barrier

And Tom is correct you need a way to exhaust moisture
We run our fantastic fan while sleeping all winter. Crack the front windows and pull air to the back of the van and out.
Good sleeping bags are key:elkgrin:

 

[Racerman27410]

I am mid process on my insulation right now so i will share my plan.

First time i actually slept in the van it was pouring rain for 4 days.... WOW was that loud! Had to use ear plugs to get any sleep at all.

With that experience i knew noise reduction was as necessary as a thermal barrier.

First i used strips of Butyl tape to dampen the areas that were single walled metal

My base layer right next to the walls (attached via 3m contact adhesive) was this closed cell foam from Harbor freight,

http://www.harborfreight.com/4-piece-anti-fatigue-foam-mat-set-94635.html

Did wonders for knocking down the noise and immediately noticed a difference in interior temps. This material is 1/2 inch thick closed cell foam, will not absorb water, and with it tight against the metal there should not be an issue with condensation. There is a smell when you first unpack the squares but it fades quickly.

my next layer will be reflectix pulled tight to provide airspace between it and the closed cell foam (reflectix gets its best R value with the air space)

I will then use this white plastic paneling for my finish surfaces

http://www.homedepot.com/p/1-16-in-x-4-ft-x-8-ft-Plastic-Panel-63003/202090190

I really dont think you can find much out there that has the R value and waterproof qualities of closed cell foam.....I may even put another layer on the roof in between the support ribs before stretching out the reflectix.

 

[birdman86]

Your vapor barrier should be on the "wet" side of your insulation
From my perspective your order should go like this from van to interior
Sound deadener-insulation-vapor barrier-finish
This keeps your insulation dry rather then allowing it to absorb moisture before the moisture gets to your barrier

And Tom is correct you need a way to exhaust moisture
We run our fantastic fan while sleeping all winter. Crack the front windows and pull air to the back of the van and out.
Good sleeping bags are key:elkgrin:

Nice thanks, a roof vent is definitely on the list, and I'm thinking about some of those marine deck plate things in the floor to provide the 2nd vent (no more open windows).

One more question has come up regarding thermal bridging though. I need to run a few channels into the van (solar power cables, previously mentioned deck plates, maybe a CB antenna cable). To minimize thermal bridging, is the general solution to just say screw it and try to do it clean, using some kind of plastic to isolate contact with the van body? I.e. maybe run a small PVC channel for the cables, and seal it with silicon? That shouldn't introduce any bridging issues....right?

 

[Racerman27410]

You can get these glands to fit whatever size cables you need to penetrate the roof..... they even make them so you can run multiple cables through them as i did for my solar panels.

https://www.amazon.com/White-Plasti...TF8&qid=1465786632&sr=8-1&keywords=wire+gland

 

[familyvan]

Be cautious with the expanding foam in the ribs as there has been a few cases where it dents the outside of the van

 

[birdman86]

The more I read the more I think I'll skip the spray foam and just run my full insulation spread over all of the ribs, maybe stuff some pink insulation where I can. Not convinced that the ribs would make a big enough difference to be worth it, especially if I do a good job with everything else.

Current train of thought is:

1 - Van wall
2 - Dynamat
3 - Spacer strips (VHB taped between wall and reflectix. Wood, closed cell foam, more reflectix, not sure it matters too much what they're made of)
4 - Reflectix
5 - Roxul rock wool or pink fiberglass - whatever home depot sells, but roxul claims water resistance so leaning to that one
6 - Foil duct insulation and foil tape (final layer, vapor barrier)
wiring would be run here
7 - Wall panels/flooring/roof panels
8 - Carpet lining (hull liner, speaker box stuff, whatever)

In place of #5 would be rigid insulation for the roof, with (space permitting) duct insulation over that to continue the vapor barrier. Do people worry about vapor barriers up into the cab, or is just cut everything off roughly at that curtain line (keeping in mind I'll have a fan and/or some passive vents anytime I'm hanging out inside)?

And for flooring I'm thinking some heavy 3/4" rubber or closed cell foam flooring that's easy to clean and remove, painted plywood under that which I can mount some tie-downs to, and a Dynamat/Reflectix/Rigid/Foil duct insulation combo under that then.

This would leave nothing screwed to the van body itself, so I'd have to use some pretty solid double sided tape or spray adhesive, and the floor would be at least partially floating. This should work in theory....I think......

One option that might be the cadillac (?) would be replacing #5-6 with thinsulate, and another layer of reflectix for vapor barrier to make up for the foil part of the duct wrapping. Is thinsulate as good as pink fiberglass?

Side question, has anyone used cork underlay for their flooring? That with some laminate on top might be a bit nicer than the rubber/foam flooring I'm currently considering.

 

[_hein_]

We recommend 3M Thinsulate(TM) acoustic/thermal insulation engineered for vehicles. We stock SM600L and SM400L which are the thickest grades. Thinsulate(TM) can be used with or without an interior 'moisture barrier'. We recommend a moisture barrier if the van will be used for extended cold weather camping. Placing or bonding Thinsulate(TM) against large unsupported body panels does a great job reducing resonance, structure born noise and vibration. Thinsulate is a very safe and easy to DIY install product. PM me for a sample. We recently insulated a Ford Transit.

 

[dlh62c]

Answers to your questions will be found over on the Sprinter Forum.

A good Sprinter Conversion Resource book.

 

[boardrider247]

Do people worry about vapor barriers up into the cab, or is just cut everything off roughly at that curtain line (keeping in mind I'll have a fan and/or some passive vents anytime I'm hanging out inside)?

I didnt worry about reinsulating the cab area, however that would be the best scenario to remove the entire interior and continue your insulation system throughout.
You will need to decide if the juice is worth the squeeze on that one

And for flooring I'm thinking some heavy 3/4" rubber or closed cell foam flooring that's easy to clean and remove, painted plywood under that which I can mount some tie-downs to, and a Dynamat/Reflectix/Rigid/Foil duct insulation combo under that then.
Reflectix would be rather pointless on the floor. I would use a heavy duty vapor barrier designed for wood floors

One option that might be the cadillac (?) would be replacing #5-6 with thinsulate, and another layer of reflectix for vapor barrier to make up for the foil part of the duct wrapping. Is thinsulate as good as pink fiberglass?
Thinsulate would be the best option and I would choose it over fiberglass (cost aside) again you will need to decide how far and how much you want to spend on this.
I used fiberglass duct wrap in my van because I was able to get it for free. And I entirely encased it within the vapor barrier so there should be no way for it to become airborn.

:sombrero:

 

[goneagain]

I recently pulled the trigger on this:

http://www.armacell.us/products/aparmaflexsaaparmaflexfssa/

Its a 3x4 sheet of closed cell neoprene foam, self adhesive backed. Has an R value of 3. Designed to be applied directly to sheetmetal ductwork to prevent condensation and heat transfer.

Its spendy. $25 for the non self stickum, and $45 for the self stickum.

I plan to use this directly on the inside panels of the van, gluing seams. I dont plan to use any other insulation or vapor barrier, just my wall panel.

Im committed at this point, but would love to hear the collectives thoughts on this.

 

[jhonarnold]

sprinter forum is the best for you.

 

[_hein_]

I recently pulled the trigger on this:

http://www.armacell.us/products/aparmaflexsaaparmaflexfssa/

Its a 3x4 sheet of closed cell neoprene foam, self adhesive backed. Has an R value of 3. Designed to be applied directly to sheetmetal ductwork to prevent condensation and heat transfer.

Its spendy. $25 for the non self stickum, and $45 for the self stickum.

Thinsulate(TM) SM600L is R5.2 at roughly half the cost.
Much better noise reduction, easier to install, and engineered for vehicles.

 

[goneagain]

Thinsulate(TM) SM600L is R5.2 at roughly half the cost.
Much better noise reduction, easier to install, and engineered for vehicles.

in order for the SM600L to deliver that R value of 5.2, It needs to be at its full 2" thickness. 2" thickness isnt going to work on my van. the armaflex neoprene I purchased is only .75 inches thick, delivering an R value of 3. The 2" thick version of this foam is R8.

It would appear that the neoprene surpasses the 3m product in reducing thermal conductivity.

SO, to get technical, tests show road noise to be in the 750-1000k hz range.

The 3m is .3 at 500hz, and .78 at 1000hz.

My 19mm armaflex is .13 at 500hz, and .59 at 1000hz.

It appears that the 600L wins in sound absorption. What are the numbers for the 3/4" version of 3m?? the neoprene sound absorption actually decreases with thickness, with the 3/4" being the top of the curve.

My main interest is controlling the temp and ocndensation. Second priority is road noise. The cabinets, bedding, and carpet will do a pretty good job of killing the noise.

Could you post specs on the 400l? I couldnt find them. If I could have both the 3m and the armaflex in the wall, seems to me that would be an ideal combination.