Sheeps Wool or Polyiso

[Fork King]

But they sure as hell will nest in it! And keep in mind that mice can get through an amazingly small crack, so if you use this, make sure your wall is well-sealed.

Thanks for the info. I think I'm going to use XPS after further research and all your suggestions.

 

[user 22017]

hmmm. $212 fir a 12"x48" batt. seems expensive.

Was that figure found on their website?

 

[rruff]

I live in the Grand Canyon National Park. Hot in the summer 90's and cold in winter 0° and below overnight.

How nice! I live at the same elevation but futher south. Have you lived in that climate? Just asking because, if you were used to a more humid climate you might think 90 was hot, but it's very dry when that happens, and if you can park in the shade it wouldn't be an issue at all for most humans. As soon as the sun goes down you can pull air through with a fan and cool your camper down. I live in a house and I'm not in the shade and don't have AC, and don't suffer. Your insulation will be better than my house has as well!

I ask because the amount of electricity it takes to run a heat pump for AC (and for heat apparently) is pretty extreme. You need a lot of solar panels and batteries to make that work.

 

[bullfrog !]

^^^where we have lived and worked in Glen Canyon National Recreation Area the last 20 years we have always had free or low cost full hook ups but that has changed over the last few years causing us to switch to being “parkies” ( working directly for the government ) and living in their housing. Working in a National Park isn’t for everyone but it can be rewarding and make CheapRV living easy. Any temperature is manageable when you have access to cheap utilities. When they stopped furnishing free propane I converted everything to electric including a fridge, 10 gallon water heater, ceramic heaters and grill as they continued to supply free electric. Now we are getting ready to boondock again a generator and large solar set up is in our future most likely or full hook up lot in town. We are at about 4500’ elevation here in Utah and it is hot in the summer and winters we take furlough in southern Arizona and boondock at around 3500’ elevation.

 

[Fork King]

How nice! I live at the same elevation but futher south. Have you lived in that climate? Just asking because, if you were used to a more humid climate you might think 90 was hot, but it's very dry when that happens, and if you can park in the shade it wouldn't be an issue at all for most humans. As soon as the sun goes down you can pull air through with a fan and cool your camper down. I live in a house and I'm not in the shade and don't have AC, and don't suffer. Your insulation will be better than my house has as well!

I ask because the amount of electricity it takes to run a heat pump for AC (and for heat apparently) is pretty extreme. You need a lot of solar panels and batteries to make that work.

I have been here 7 years now. I love it but want to go part time and spend my winters boondocking in Quartzsite for the winter.

I am going with a 24v 2000 watt solar system and 400 amp hour bank.

 

[Fork King]

^^^where we have lived and worked in Glen Canyon National Recreation Area the last 20 years we have always had free or low cost full hook ups but that has changed over the last few years causing us to switch to being “parkies” ( working directly for the government ) and living in their housing. Working in a National Park isn’t for everyone but it can be rewarding and make CheapRV living easy. Any temperature is manageable when you have access to cheap utilities. When they stopped furnishing free propane I converted everything to electric including a fridge, 10 gallon water heater, ceramic heaters and grill as they continued to supply free electric. Now we are getting ready to boondock again a generator and large solar set up is in our future most likely or full hook up lot in town. We are at about 4500’ elevation here in Utah and it is hot in the summer and winters we take furlough in southern Arizona and boondock at around 3500’ elevation.

Glen Canyon is awesome. Yes, we do not have free utilities but electricity is a reduced rate and cheaper than propane.

I also want to get ready for boondocking so I'm trying to insulate as best as possible and a large solar setup as possible.

 

[bullfrog !]

^^^For us being so used to hot summer heat it is difficult to find anywhere in the continental US where it stays “warm enough” but somewhere without mandatory periods of snow is good enough. My latest DIY camper started out as an air tight super insulated box. I soon discovered I needed a lot of ventilation to prevent condensation. In fact so much ventilation my heating system needed to change. Summer time AC and warmer air it wasn’t a problem. Looks like you are off to a good start. High Desert Ranger (HDR) was building out a cargo trailer when he passed. You might gain some insight viewing his old build postings here as he was a very knowledgeable boondocker.

 

[Fork King]

Thanks for the info. I will check out HDR old post.

I think I'm getting Analysis Paralysis.

 

[Quinn]

I am building a new 24' 8.5' wide cargo trailer. I will live in year round. It gets in the 90's in the summer and below freezing in the winter.

I plan on going 4" preferably Sheep's Wool or PolyIso. Anyone have experience with 4" or greater for heat and AC retention?

I do not mind spending the extra if it will be worth it.

Leaning to the Sheep's Wool for moisture retention / release ability and still maintain insulation value. It's sound proofing ability. No offgassing and fire retarding ability.

Thanks,
The Fork

chuck Cassady has a video on insulation that will make you sit up. Don’t be discouraged by the title, and do what you think is best, but he seems informed. Google insulation scam haha

 

[Fork King]

Lol, I just watched that. Thanks for sharing. I tried calling a few spay foam installers once they heard Cargo Trailer they all said no. I wanted to get a few estimates. Looks like at this point I'm going XPS.

 

[rruff]

Looks like at this point I'm going XPS.

Ya, it's about as good as insualtion gets and is cheap and easy to use. If you seal any gaps with spray foam, you'll be in good shape.

What will you have for your interior walls, though? I think PMF (canvas and Titebond) method would work well, but it might be a little rough for your tastes.

 

[Fork King]

I was going to use 1/4 cedar planks or birch plywood.

This build is going to be expensive. I have been planning this for a long time. So, I am not too worried about cost within reason.

My wife is disabled, so I need to make it wheelchair friendly. This is also our early retirement home.

 

[rruff]

I was going to use 1/4 cedar planks or birch plywood.

Glued to the foam would be best I think, and maybe thinner. Look at marine ply. 4mm Meranti would be plenty. https://www.marine-plywood.us/mahogany_meranti.htm

A long time ago I built a camper with 2.7mm luan on the inside (glued to foam) and had no issues with durability.

 

[jonyjoe303]

I been using the 4x8 foot rtech 1/2 inch foam from home depot. I cut into small sections and hotglue it directly to the bare metal ceiling no air gaps. On the roof I have several layers of foam, hotglued one on top of the other, 3 to 4 inches thick. Once its thick enough you no longer feel heat coming from those areas even when parked in the sun.
I recommend hotglue because it dries quickly (within minutes) and has no fumes, thats why I cut the foam in small 1 foot sections, if the sections are too large the hotglue starts drying before you place on the wall.
I started with 1/2 inch layer first and when that wasnt keeping the van cool enough, I added more layers. With enough insulation you wont need a large AC to stay cool, all I use is a small swampcooler in summer. For winter beside the insulation, you need to make sure your vehicle is as airtight as possible, any cracks where air can come in will defeat any insulation you have no matter how thick. Maybe a small roof vent if you run a heater.
Use an IR thermometer to find cold or hot spots and add more insulation to those areas.
Foam insulation works great but only if its thick enough.

 

[maki2]

The temperature of a hot metal roof in the sun reaches a high enough temperature for the standard types of hot glue sticks to soften and loose their grip. I had a friend who tried that in his cargo van with foam insulation panels. It worked fine all fall, winter and spring but then on one rare 90+ degree hot summer day in Seattle his ceiling insulation all fell down.

Adhesives have temperature ranges not just for application times but also for situational useage. When choosing adhesives to use you need to pay careful attention to that temperature range data. Not just for glues but also for adhesives tapes including VHB tapes and those sticky adhesive backed Velcro products and even electrical tape as there is a type of it that is rated for high temperature use and not all of the common electrical tapes sold are rated for high temperatures.

The old reliable adhesive for putting up headliners is the VOC containing yellow colored contact cement. That product is still available in Hardware stores.

Water based contact cements need at least on water permeable surface in the application or it can’t cure. So foam to metal is not a good match for water based glues.

3M 90 spray contact adhesive has a high temperature rating and can be used for installing insulation to Van walls and ceilings. 3M 70 does not have a high enough temperature rating for use in installing insulation to the metal surfaces on vehicles.

Polyurethane hot melt glues that come in a cartridge that is placed into a heating unit before gunning it out does have a high enough temperature range. But it is an expensive option for the equipment and the hot glue cartridges.

Polyurethane adhesive caulking is good for such a temperature vulnerable application of insulation to metal
Roofs and walls but it will need some temporary supports to hold it in place while the adhesive cures. Using “spring board sticks” often works for that type of temporary pressure support.