Insulating a van to live in

Not a tiny house as such, but if one wanted to insulate a cargo van as cheaply and easily as possible/least amount of work, how would you go about it?

I was thinking maybe this ;

Closed cell  (waterproof) camping mats from the poundshop and carpet taping them straight to the bare metal walls and roof, making sure to overlap the mats wherever possible, or fill in gaps with some sealent.

For the floor maybe just a sheet of polythene then carpet underlay and carpet.

But would condensation get between the camping mats and metal? Would condensation/moisture eventually break down the mats?

What would you use inside the panel spaces?

Cheers for any help.

There's a lot of info about RV construction that would apply to a van.  RVs have been around for decades, and have great design and practical ideas that have worked for most people.

There may already be a type of lining that is meant to keep the noise levels down, so it may be helpful to keep that, or research other types of noise dampening fabrics.  Be careful of anything that could off-gas chemicals.  If it doesn't smell good to begin with, it's probably not okay to breathe in an enclosed space.

I think the main consideration in a vehicle or building that isn't going to breathe like wood, is moisture/mold.   Regular fiberglass insulation, based on the  R-value that you will be in for winter against the metal, then use a breathable thin drywall, or cement-based drywall over that.   It adds weight, but it absorbs moisture from the air and from breathing.  If you've ever spent the night in the car, and woken up with condensation all over the windows, that's a lot of moisture you don't want inside during the damp months.

You can hang things from that drywall with molybolts, making sure it's not too heavy.

While synthetic carpets may seem practical, they off-gas a lot of chemicals and do not absorb moisture, particularly the backing.  Some kind of washable light-weight peel-and-stick tiles on the floor with removable, washable wool or cotton throw rugs that can be hosed down and dried outside on the line work well.

RV design ought to talk about air vents that help circulate the air inside a van, and probably already exist, so try not to cover those up.

you can insulate anything just by creating an air space.  if I had a couple hours to insulate something like a box truck - I would just go buy sheets of plastic and some general adhesive.  Just make wall out of the plastic to create a foot air gap on the sides and maybe a 2 or 3 foot air gap on the ceiling.  Put a few pieces of plywood on the bottom and maybe a carpet over it, and you could heat that space in winter with a bic lighter.  Ventilation for any heating device would be a problem.  Possibly an electric space heater would work.  The air would be so dry - any person or animal will quickly develop breathing problems.  If I was going to do something that I wanted to last I would still use plastic sheets, but maybe build a frame out of strapping or some cheap wood to give it a little structure.

I actually put a ceiling on a room at a camp by creating a 2 foot air space with plastic.  Then to make it look better I found some cheap fabric and just tacked it up to the framing, sort of looked like a huge pillow or couch cushion.  I think that was maybe 10 years ago and it is still there.  No insulation on the walls.  At 20 degrees outside that 10 by 10 bedroom heats to 70 degrees with a little space heater in about 30 minutes.  I was up there a few times and ran the heater too much and boy does hot dry air stink to breath, better off being a little cold than getting respiratory problems in the winter.

Insulation that can't absorb moisture would require a heater being on 24/7 when the humidity is up.   Even then, living in a "plastic bag" might be the right temperature when heated, but where does the moisture go?  

I grew up with my parents traveling in an RV, and have lived in an RV that had that faux wooden paneling, pretty much plasticized paneling, and it was a constant battle to keep condensation off the windows and the walls.  My dad had space heaters on in his RV when it was parked and not being used, and we didn't live in a terribly humid area, except in the winter.

And how can plastic stand up to things hitting it, sharp edges cutting it?  It just isn't a durable surface for all of the crawling around, hefting things in and out of a van, and hauling things in a van when not camping in it.

What landfill is it going to end up in when it starts to fall apart?  I don't know what they've done to sheets of plastic these days, but it's changed from 20 years ago.  Some plastic sheeting starts shattering into bits in a year or two.  Who knows what it was off-gassing up to that point?  I just don't buy it anymore, it's such frustrating stuff.

plastic won't stand up, but it is cheap and quick.  real thing I wanted to try to get across is it is the air gap that really creates an insulation effect.  even the walls in homes, the insulation is there to slow convection in the wall, to slow the rate of thermal exchange through the air that fills the gap in the wall.

I used poly-iso two inch thick foam insulation in the compartments in the van walls, with lots of great stuff foam spray as clue and to fill in the cracks.  Then the inch thick stuff on top of (bends better) and corrugated plastic finish on top of that (like the stuff they make political signs of).  Lots of white duct tape on the outsides held everything together, but it was all glued with liquid adhesive.  I was out West, so didn't worry too much about humidity, and never smelled mold.  I ran a fan and monitored humidity with a sensor.  A lot of people put down a vapor barrier between the metal and their insulation, but I didn't think it was necessary.  You will want lots of ventilation anyway for stuff like cooling and cooking; that will help keep moisture out of the air and reduce condensation.

In small spaces, you will want many airchanges per hour worth of ventilation to avoid buildup of co2 and other human and building material gases.  To do this and maintain a desired temperature range inside the van, you'll want a heat exchanger.  if your intake pipe,is 3in duct run inside a 4in duct exhaust line for the length of the van, that would do.Ts to split the inner and outer ducts and then put your intakes and exhaust at oppsite corners.  both inside the van and outside it. Keep your fresh air intake as far from the engine exhaust pipe as possible and have a good Carbon monoxide alarm.  

You are a hot moist ball of meat, the van is a big metal heat-sink just waiting to condense all that water.  You need a moisture tight barrier between you and the metal. Plastic,drop clothes,work.

you want a durable surface between you and the plastic... wood paneling, plastic political signs, anything but cardboard is good here.  Between your vapor barrier and the van shell you want insulation.  Polyiso or polystyrene is best R per inch and you don't have much room for,thick layers.  i endorse 2 inches foamboard sealed with expanding foam as someone else said.

lastly,  make sure the roof,of,your,van,is rain tight and painted and sealed before you install all this.  Much harder to find and fix leaks after.

have fun.

Like others said, outgassing is a big concern in such an enclosed space. (Probably should be regardless of the size,.  I mean, how much poison is too much?  But I digress...)

Anyway, I saw a van build project where the dude insulated with batts of lamb's wool.  Cool looking stuff.  Here's the build video about that:

Mike Branscombe wrote:you can insulate anything just by creating an air space.  if I had a couple hours to insulate something like a box truck - I would just go buy sheets of plastic and some general adhesive.  Just make wall out of the plastic to create a foot air gap on the sides and maybe a 2 or 3 foot air gap on the ceiling.  

If the air space is greater than 1/4" you're going to get convection in that space, which will drastically reduce the effectiveness.  A 2-3' air space will just waste space and not be effective insulation.

My cheapest and quickest thought would be a quilt/ curtain system; some sheets or blankets from Goodwill, a layer of batting between them and suspend from wires through a line of eyebolts or on a rail. It would be modular, cheap to tweak if needed with thicker/ thinner batting, and breathable/natural materials if wanted. If the fabric is not directly touching the side with a slight airspace it should dry pretty well on its own, if not the panels could be thrown on a line to air dry outside .  It could also be adjustable around your sleeping space at night if needed, like an old style bed curtain to keep you warmer.

Another benefit of the curtain system stephanie speaks of above is that they can be cleaned or replaced easily and drawn back for light in the day or privacy at night.  Also what climate is this,van being prepared for?

I like reflective one side/white one side double bubble. It cuts easy, is flexible, thin and light weight. Can be tailored over foam sheets or thickness but up in layers for additional insulation, reduction of convection loops, sound damping, etc.

No/low offgass or odor, no fiber shed, high performance, water/vapor barrier.

I use it quite a bit. As thick as you can get and double, triple, etc...

https://www.walmart.com/ip/InfraStop-48-x-100-Double-Bubble-White-Reflective-Foil-Insulation/717495288?wmlspartner=wlpa&selectedSellerId=8033&adid=22222222228070835261&wmlspartner=wmtlabs&wl0=&wl1=g&wl2=m&wl3=182285437576&wl4=pla-285617039949&wl5=9058203&wl6=&wl7=&wl8=&wl9=pla&wl10=115059144&wl11=online&wl12=717495288&wl13=&veh=sem&gclid=EAIaIQobChMIzNeW0JXt4gIVgUGGCh2lHQiyEAQYAiABEgKRKvD_BwE

White on one side looks decent, is tough but could use sheathing or a wainscot of something.
The tape for this stuff sticks, worth the money. Almost nothing conventional stics well to polyethylene.

The reflective side is quite festive with the right lighting! We use it as insulated window panels in the winter.

Makes it easy to perform great looking high performance electric water heater wrap too. Our woodstove boiler storage tank is diy and wrapped multiple times in 5/16" double bubble reflective facing in white facing out for looks. Looks nasa...

I found reflective aluminum foam also. More sound reduction, more weight, less insulation value?

Here is a page about "zero VOC insulation". https://www.mychemicalfreehouse.net/2013/01/zero-voc-insulation.html

I'm planning to refit an old horse trailer as a micro-cabin and I'm still in the process of deciding on insulation.  I'm currently leaning toward polystyrene foam board because of low cost and relative ease of installation.

James Bong wrote:Not a tiny house as such, but if one wanted to insulate a cargo van as cheaply and easily as possible/least amount of work, how would you go about it?

...

Cheers for any help.

Definitely check out CheapRVliving  It's what they do all the time.  https://www.youtube.com/channel/UCAj7O3LCDbkIR54hAn6Zz7A  

The standard way to do it is with spray in closed cell foam.  And that'll be full of toxic gick.  

One way many people start doing it is by shoving fiber bat insulation everywhere they can.  This might not be the best plan due to mold ( very bad plan really ).  After you understand where to, and not to use it.  There is a company that does 1/2 per-prepared meals / teach you how to cook things.  And the boxes they are currently shipping their food in boxes insulated with cotton/denim batting.  Ever box shows up with another few square feet of insulation.... Talk about an awesome build as you go solution. ( https://support.homechef.com/hc/en-us/articles/210097943-How-do-I-dispose-of-the-box-packaging-materials- )

https://www.reflectixinc.com/

Also foil lined bubble wrap. I put some on the inside of a dark colored shed roof and it did wonders.

There is an order of priority. As below, in my experience:

1) Plug/seal _all_ the air leaks. Holes in the floor and walls, bad door weather strip, leaks around anything like built in refrig or furnaces with connection to the outside.  When the wind blows, it will _quickly_ empty your little space of its heat unless you get all the leaks.

2) Install a curtain between the front cab and the living space. Make it as tight as possible. You don't want to heat that space and you'd rather not have all the windows fog up when you're in residence. Judgment call here. Using the front windows for ventilation (see below) is an option. But seal all the holes up there. Maybe throw pretty covers over the defroster vents to stop air circulating.

3) Decide how you will ventilate to get needed fresh air flow. Experiment. You need a little fresh air but you _have_ to control it. The biggest reason, barring you put in poison offgassing stuff, is the moisture you put in the air by breathing. You are an always-on humidifier and create pints of water every day. You want that moisture gone or at least diluted. One or two _small_ controllable openings low, one or two high and space these front and back to get cross flow. It's a real challenge to make it neat, controllable, easy to use and durable, but it's not rocket science. One of the opening might incorporate a small twelve volt fan for when nature doesn't help you here.

4) Cover the floor w/something like thin plywood and cover that w/throw rugs to give you a little comfort.

5) Provide yourself with _good_ bedding which keeps you warm below as well as above. For real cold, a balaclava (I find "night caps" just come off and get lost immediately).  Maybe a pair of gloves and heavy wool socks used only for the bed. Now you can survive indefinitely.

6) For comfort, provide yourself with a few layers of comfort clothes which have long sleeves and come up to your neck. "Cardigan" sweaters are traditional for old geezers who are always freezing to death and there's a reason: They go on/off easy (they're not pull-overs), they offer control by how high you button them, they come in various weights; and they're just really comfortable and easy to use. Heavy sweat pants and luxurious slippers with hard souls. You want to get your shoes off quick when you come in. For real cold, knit gloves with the fingers tips cut out, and a watch cap. You don't need windproof stuff for your in-house wardrobe.

Heat _you_, not space. When cold, drink hot tea - hot fluid _inside_ you works much better and faster than heaters _outside_ you. I guess you could use something heated for your bed, but I have found that if you have very good bedding, you don't need to force heat it, at least down to 10F. - you take care of that just by getting in and staying there.

But it all goes to hell (blows away) if you don't seal all your leaks and then design an just-enough ventilation system.

After that, insulation is all gravy and you don't need as much of it. Start with the floor or roof, then do the one you didn't. Try to use stuff that can be _effectively_ sealed on the inside to prevent moisture from getting past it. I you don't keep moisture from getting around your insulation you get condensation behind it (no nice air flow there) and bad things start to happen. That's one of the reasons it's the last thing on my list - it can make more problems. But if you do it right it will allow you to reduce your ventilation because there's less cold surfaces to condense on and the inside can tolerate a higher humidity. Cutting back ventilation starts to look real nice when the wind is blowing and it's 10F. outside.

Burning something (to get heat) puts a lot of moisture into the air and you need to deal with that carefully or you have a huge condensation and then mold problem.  That's another topic.


Cheers,
Rufus

That summary by Rufus was pretty good. I hope I never need it lol. My vehicle has wheels to leave. So far the mild Puget Sound region is as cool as I care to overwinter. Moisture has been a challenge sometimes but I find I get enough sunny days to heat up the vehicle and dry it out. With only one person inside I can manage the moisture. I can imagine a vehicle with several people, pets, and a very cold climate would have a huge moisture condensation issue. My thought was to use Permaculture thinking and design a designated condensation surface then harvest the water from that surface? .
Has anyone used a tent inside?  I like tents. They breath and are 10 degrees warmer with just body heat. I used a tent in a unheated bunkhouse and barn. It was great. Now I’m seriously considering one in the rear bedroom of my Motorhome. Also blankets can be draped over a tent. I bet this would be 20 degrees warmer depending on how many blankets are used. A very small electric heater could warm a tent to cozy temperatures. I’d like a 200 watt heater that threads into a light bulb socket. They used to make them and can be found in antique stores. Or build one using nitrile wire?
The tube-in-tube countercurrent air-to-air heat exchanger is something I’ve been wanting to try. They can be built for under $50 which is peanuts if it works. There’s a instructables.com build of this type of heat exchanger with good reviews.
Here in the mild Puget Sound you can leave the leaky seams, old bolt holes, old screw holes, etc and get just the right amount of ventilation lol. I’m spoiled. Somewhere colder and I’d need to be more careful. We sometimes get a week or two of below freezing. People around here are seldom ready for it lol. In Seattle they called one episode Snowmaggedon.

I just watched a YouTube video of a guy in a Suburban, he had about a 5lb bag of silica gel that was somehow open to the atmosphere for moisture control. He didn't talk about it so I have no idea if it actually works. A 5lb bag from Hobby Lobby is $17.

I'm guessing you already finished insulating your van, but I wanted to share some info for anyone else still looking for natural insulation materials.  Off-gassing is an issue for me, so I'm opting to insulate a high-top Chevy conversion van with natural materials.  I discovered 20x40x2 inch cork insulation panels, (7 pounds each), from a company in Savannah, Georgia called Jelinek.  The cork is heated in a steam autoclave which brings out natural resins that adhere the granules together.  No man-made adhesive needed!  They do sell other cork products that contain man-made adhesive, so read before you buy.  The 2" insulation panels I got are somewhat crumbly, so they need to be handled with care.  Even after cleaning with a vacuum, dust and little bits of cork will fall out, so I decided to wrap them in aluminum foil to create a dust barrier and boost the insulation factor.  After wrapping with foil, I hand stitch a custom fitted wool felt cover over each panel.  The wool cover creates a small air gap between the foil and surfaces of the van walls and ceiling where the panels are fitted.  This is important because foil will transfer, and not reflect heat or cold if it is in direct contact with another surface.  With the panel edges butted closely together, the wool closes gaps.  In the spaces where I can't fit panels, such as in the van's structural ribs, I'm wrapping loose wool in foil and tucking it in.  To hold the panels in place, I'm using tension and friction wherever possible on verticle surfaces, and sewn-in magnets wherever needed.  (The van walls are metal).  For the ceiling, there are 1x4s embedded in the fiberglass roof that I will use to suspend panels with perforated plumber's tape and screws.  At some point, I'd like to use something like bead board wood strips to cover the panels and make the ceiling look nice.  Maybe woven wool fabric to cover the wall panels, (removable for washing), or embossed metal panels.  

It's been a while since I did the research that led me to decide on cork, aluminum foil, and wool felt, but if I remember correctly, cork does not retain moisture, and wool actually has a reaction when it gets wet that creates heat and helps it dry out faster than other fabrics. If you're interested, you can read up on it to confirm that.  Hope this will help someone.  I did quite a bit of research before settling on these choices.

Before starting the insulation install, I used the van without heating or cooling in temps ranging from 26-85 degrees F.  Passive solar heated the van to a comfortable temperature during cool weather by 9 or 10am, so any bathing and changing clothes was best done after that.  For sleep, I gave up changing into pjs on the coldest nights, but instead, kept on street clothes and a down coat to prevent loss of body heat.  Also used a small folded blanket to keep my head warm.  It did get unbearable in hot, humid weather above the mid 80s, even with windows and doors open.  Insulation should help quite a bit once the ceiling is done, especially.

I never had a problem with condensation buildup because I always kept windows cracked for ventilation.   I've since installed bull nose vents with inline fans in the rear of the high top.  That feels a lot safer than keeping windows cracked for ventilation.  I can run the fans when I have shore power, but hope to add a solar system that will let me run them and a dehumidifier in the future.  The fans are each 20 watts, and can both run the same direction, or one each way for a quick air exchange.