Hi,
I'm sure you will get many conflicting responses

My favorite:

Walls and Ceiling: 1 inch Polyiso - you can probably get at HomeDepot or Lowes
Glue the Polyiso to the sheet metal with Great Stuff foam in a can - use spring sticks to hold it in place until the Great Stuff sets.

Floor: 1 inch thick XPS rigid foam board
Use half inch plywood over the XPS.
No need to fill the floor corrugations.
I would glue all the layers together, but many don't.

This is enough for 3 season vans.
If you plan to use the van in a cold climate in the winter, then:

Fill the frame cavities with something like Thinsulate.

Insulate over the inside surface of the frames with insulating foam tape that is 1/4 to 1/2 inch thick to prevent thermal bridging.

More info:
Insulation testing...

Thermal bridging testing...

Gary

 

My favorite:

Walls and Ceiling: 1 inch Polyiso - you can probably get at HomeDepot or Lowes
Glue the Polyiso to the sheet metal with Great Stuff foam in a can - use spring sticks to hold it in place until the Great Stuff sets.

Floor: 1 inch thick XPS rigid foam board
Use half inch plywood over the XPS.
No need to fill the floor corrugations.
I would glue all the layers together, but many don't.

This is enough for 3 season vans.
If you plan to use the van in a cold climate in the winter, then:

Fill the frame cavities with something like Thinsulate.

Insulate over the inside surface of the frames with insulating foam tape that is 1/4 to 1/2 inch thick to prevent thermal bridging.

 

I used Havelock wool, with Polyiso on the floor and ceiling. If I did it again: I'd just go with polyiso. It's effective, easy to install and cheap. I think we get too complicated on this subject. Nothing is going to keep a van much more than 10• better than the outside temperature. The money I spent on Havelock would have better been put towards a heater, a fan, or window covers.

 

I did very similar to Gary and I've been super happy with this method. I personally used 3M90 to glue on the polyiso, and great stuff in the gaps. I would do it that way again over great-stuff-as-glue, mostly cuz I like things to be easy and 3M90 doesn't need any shoring to hold it up while it cures.

I stuffed the large cavities (doors, bottom half of C pillars) and covered other ribs with 1/2" foam.

I have no experience with Thinsulate, and might consider it for a second build just cuz it seems a bit easier that cutting all the shapes out of foam board. But it's thicker, and in many places (mid walls mainly) I don't have room for 2". And where I do have extra space, doubling up foam board should insulate better than Thinsulate.

 

Hi, What or how did you fill your cavities?

 

Thinsulate is where it's at for the doors and in the roof corners. You can cut it in strips and stuff the cavities without glue and the black backing holds it together and lets you keep it away from the moving parts.

It's about R5 and 1.5" thick and in my area around the same price as Polyiso foam board. I did the walls over and under the windows with Thinsulate. There's 1" Polyiso in the ceiling between the ribs with another 1/2" of XPS over that held up by underlayment screwed to the ribs, and 1/2"XPS on the floor with 1/4" plywood on top. I was concerned that the floor would not be stiff enough but it was suggested on here and I'm glad I listened.

On our van the roof and walls put off a ton of heat since it's black so that's where the extra insulation went. The floor had to be thin to keep enough headroom for us to stand up straight. I'm 6'2" and I can stand with shoes on, but barely.

Honestly, If we had a white van, I would just use Thinsulate everywhere but the floor. Putting that stupid foam overhead sucks.

 

My wife and I decided to do Havelock wool and cotton tubes. We were concerned about having too much plastic and off gassing materials in such a small space. We also have a wood stove, and the fire hazard was another consideration. The wool may not give the best insulation, but it works for us as weekend warriors.

The cotton tubes are filled with the wool and placed in all openings of doors and panels. The reason that we used cotton tubes was that it looked so hard to glue the wool battens in place. We were also concerned that the wool would all go down to the bottom of the panels when driving on bumpy roads. The idea came really from sleeping bags and down jackets where they have baffles to make sure that the down doesn’t collect all at the bottom.
We don’t have any moisture barriers. So far we have not had any problem with moisture, but we do use the woodstove and that gives dry heat. In the winter, we collect the water from the windshield in the cabin, so that it doesn’t hang around.
This may not be the easiest or best option if you are spending full time in your van, but it works for us, as I said.

 

Polyiso + spray foam seems to be the best way to create the tightest barrier. THe common complaint I read, or concern, people have with Thinsulate and Wool is it’s moisture absorption ability in the event of humidity build up. Now the caveat here with board + foam is in the off event of needing body work or access to wires it could be more of a time sink to get it back off and in over wool/thinsulate that can just be ripped off.

 

I used Thinsulate in my white van. Two layers in ceiling, 1-2 layers in lower walls, loosely stuffed in cavities. Full uncovered windows all around, no insulation in floor or doors. In winter, a 1500W space heater can maintain a 40° differential; the Webasto can maintain more. In summer, I can maintain ambient with the MaxxAir and Tyvek covers on the outside of windows. I’m happy.

 

Hi @MsNomer, for your layers of Thinsulate, for the second layer do you just spray the M90 spray onto the black part of the thinsulate that is already attached to the wall? (I mainly just wanted to make sure this didn’t pull the first layer apart with weight being added to the other side).

 

What is a good sound deadening product in addition to the wheel wells where else do you need it?

In addition to its thermal insulating properties foam glued polyiso also provides great sound deadening.

 

I used butyl mats everywhere for sound deadening. I also used Thinsulate everywhere (except the floor, I used 3/8: neoprene foam). If I were to do it again, I would limit the use of butyl since Thinsulate does quite a good job of sound deadening. Wheel wells and maybe a bit on the ceilings and floor.

Thinsulate + 3M90 can insulate a van in a day. Super-fast: rough cut, spray, slap up, move onto next panel. Don't follow the 3M instructions; a light spray on the insulation is all you need. Slap it up. It is permanent (but easy to remove if needed). Easy to stuff cavities, easy to squish into corners. Not cheap but time is worth something. Also, no worries about moisture being trapped behind the insulation.

Given that the windows are the PRIMARY source of heat loss/gain don't obsess over a tight insulated van unless you devote at least as much time to the windows. I used Arctic Tern windows. Pricy, but very well insulated + simple aluminized bubble wrap insulation for the front windows. The 2kw Webasto keeps the interior at 70+ down to 14f burning around 1/2 gal of fuel over 12h.

Yes. The floor is cold. Wear socks.

 

Totally agree with others about Thinsulate, we did butyl sound insulation patches and then polyiso/spray foam over it on the walls and ceiling, and if we had to do it over again we would just do thinsulate and maybe some butyl on the wheel wells and ceiling (for rain sounds). The butyl and polyiso took a long time with all of the cutting and fitting, when we just used Thinsulate on the slider and rear doors it's so quick and easy.

 

I was insulating our van last week and took the chance to compare the leftover Thinsulate to the Polyiso I had put up with contact adhesive. I did two roof sections with foam and two with thinsulate and I could not tell the difference between the two. I did the rest of the ceiling with Thinsulate. I think the small difference in performance is offset by the fact that you can't get as good of a fit in the gaps. Admittedly I did not spray foam the 1/4" gaps between the foam and the metal crossmembers but in the end I decided that the extra effort did not really make much of a difference.

It was 76 today and the 9,000 BTU air conditioner was barely able to keep up with the head load from the direct sun on all of our windows, it's going to take some window covers to keep it cool when it's really hot out. I see why the factory builds with barely any insulation throw 13,500 BTU ac's on them, the heat from the cab is nuts.

 

I was insulating our van last week and took the chance to compare the leftover Thinsulate to the Polyiso I had put up with contact adhesive. I did two roof sections with foam and two with thinsulate and I could not tell the difference between the two. I did the rest of the ceiling with Thinsulate. I think the small difference in performance is offset by the fact that you can't get as good of a fit in the gaps. Admittedly I did not spray foam the 1/4" gaps between the foam and the metal crossmembers but in the end I decided that the extra effort did not really make much of a difference.

It was 76 today and the 9,000 BTU air conditioner was barely able to keep up with the head load from the direct sun on all of our windows, it's going to take some window covers to keep it cool when it's really hot out. I see why the factory builds with barely any insulation throw 13,500 BTU ac's on them, the heat from the cab is nuts.

Hi,
Curious how you measured the difference?

The Thinsulate is thicker than 1 inch Polyiso, so it gets more R value from that even though its R value per inch is lower.

To me, the only really significant difference is that the Thinsulate is very water vapor permeable and you will get condensation on van sheet metal. For a lot of climates and uses this probably does not mater much, as long as the conditions inside the van let the condensation dry up.

For vans used in really challenging climates, using two layers of Polyiso to get up to the max thickness you can tolerate without losing inside space is going to perform significantly better on heat loss or gain than the same thickness of Thinsulate.

Gary

 

Hello, I have been doing a lot of research and find it gets more confusing rather than less confusing. I have a white van Pro Master 159 high roof and live in NE and will use it seasonally for road trips etc.

Does 3M Thinsalate make the most sense for the walls or Lambswool? Will it be enough insulation? Where are good places to order it?

What do you put over the steel frame members for insulation?

What is the best product for insulating the floor? Ceiling?

What is a good sound deadening product in addition to the wheel wells where else do you need it?

Thanks!

I THINK YOUR BEST BET IS SPRAY FOAM, WHICH IS WHAT I PLAN ON USING. CHECK OUT THE VIDEOS ON YOUTUBE FOR THE BEST REFERENCES. MESSY PROCESS BUT DEFINITELY THE MOST EFFECTIVE WAY TO INSULATE & SOUND DEADENING.

 

Hi,
I insulated my van with spray foam, and if I had another van to do, I'd use Polyiso glued in place with Great Stuff.

My thinking is that Spray Foam is fine, but it does not do any better a job of insulating and controlling moisture than Polyiso, and its quite a bit more expensive with lots of ways for things to go wrong.

Gary

 

These hydraulic jacks are so helpful with almost every phase of a van build. You can control where you drill and mount things. One of the most helpful tasks is putting up polyiso on the ceiling.

 

That's the ticket!

What is your floor to ceiling height in a build like that? At 6'2 my hair is touching the ceiling with a 1" thick floor and a ceiling that is 1" below the ribs. I had to use 1/2" insulation and 1/4" plywood on the floor to be able to stand up straight. A build like that sure would be easy to heat and cool though!

 

“I do believe that their system they had setup with an HRV of Austrian ancestry had a lot of influence with keeping humidity low enough to prevent moisture buildup within the tightly sealed shell.”
Forgive my ignorance, what does HRV stand for?

 

Heat Recovery Ventilator

https://en.wikipedia.org/wiki/Heat_recovery_ventilation

 

High Roof Van

 

Hi Gary, Hoping I can follow up with a couple of questions. Your first post was very helpful.

The floor you suggested with 1" polyiso, 1/2" plywood, glued together- what type of plywood would you use for subfloor?

ARE YOU USING SOUND DEADNER? IS SO WHICH DO YOU SUGGEST? We will be using polyiso on walls and ceiling.

ARE YOU GLUEING THE POLY FIRST TO THE FLOOR OF THE VAN AND THEN ALSO GLUEING THE POLY AND PLY TOGETHER? WITH YOUR METHOD THERE IS NO NEED FOR A SUBFLOOR FRAME CORRECT?

WHAT DO YOU SUGGEST FOR A FINAL FINISH FLOOR? DO YOU PUT THE SUB AND FINISH FLOOR FIRST THEN CABINETS?

WIRING IN AFTER THE INSULATION SO YOU CAN FIND IT AND MAKE CHANGES IF NEEDED?

Thanks very much.

 

Hi Gary, Hoping I can follow up with a couple of questions. Your first post was very helpful.

The floor you suggested with 1" polyiso, 1/2" plywood, glued together- what type of plywood would you use for subfloor?

ARE YOU USING SOUND DEADNER? IS SO WHICH DO YOU SUGGEST? We will be using polyiso on walls and ceiling.

ARE YOU GLUEING THE POLY FIRST TO THE FLOOR OF THE VAN AND THEN ALSO GLUEING THE POLY AND PLY TOGETHER? WITH YOUR METHOD THERE IS NO NEED FOR A SUBFLOOR FRAME CORRECT?

WHAT DO YOU SUGGEST FOR A FINAL FINISH FLOOR? DO YOU PUT THE SUB AND FINISH FLOOR FIRST THEN CABINETS?

WIRING IN AFTER THE INSULATION SO YOU CAN FIND IT AND MAKE CHANGES IF NEEDED?

Thanks very much.

I'm not Gary, but I'll drop my 2 cents anyway lol.

I did my floor before doing much research and definitely before I heard of people gluing or bolting it down. Dropped 1/2" ply (basic structural ply) on 1" XPS, connected the edges together, and nothing to hold it down. It can't go anywhere anyway unless I roll the van. My floor has 25,000 miles and we've been living in the van full time for a year and a half, and have not had any floor issues. Seal all sides of floor plywood just in case you get any moisture stuck down there.

Generally for rolled product flooring it's fine to go under the cabinets, and easier that way. Just be careful during the rest of the build cuz it's easy to drop stuff and damage the floor while under construction. I did my floor after cabinets because I used LVP - click in flooring. Looks good and fairly easy, but still took several hours. LVP expands and contracts a lot with temperature change so it usually goes around cabinetry with a small gap at the edges (covered by trim of your choice) and nothing screwed through it. I definitely banged up my subfloor a lot during my build but didn't care - it all got covered up at the end.

Wiring... in general people like to do it after insulation for easier access. Especially if you are using foam board, you can't really put wires behind that. Still, behind walls is still a pain to access/replace unless you pull the new wire through with the old. It's easy enough to hide wires if you build walls first. Some do a chase at the floor behind cabinets. I did some wires under the bed to cross to the other side, some at the back of the counter (covered by a storage tray I built), some in the metal ribs of the van.

 

Wow thanks for the quick reply. What did you seal around the edges of the floor with?

Were you happy with the LVP flooring and would you use it again?

We are also trying to figure out swivel seats. We want them and thought we would add them but after looking at the forum people raised lots of questions. We already ordered the van and the swivels from manufacturer were pricy. Any thoughts? We are getting a 2500, 159 2300 PM hightop.

Also what did you insulate ceiling and walls with and are you happy with it?

Anything else really important you learned from your build? Sounds like it went well.

 

Wow thanks for the quick reply. What did you seal around the edges of the floor with?

Do you mean the subfloor or the gaps around the LVP?
I used Lexel around LVP cuz it's waterproof, flexible, clear, and also acts as glue (I used it to hold on some trim). But also I try not to spill. There are definitely unsealed spots here and there.

Were you happy with the LVP flooring and would you use it again?

I would definitely use it again. I got a wood-look and it goes nice with the rest of the van. Make sure to account for the LVP thickness and any trim you might want to use when building cabinets - so drawers and doors will open.

We are also trying to figure out swivel seats. We want them and thought we would add them but after looking at the forum people raised lots of questions. We already ordered the van and the swivels from manufacturer were pricy. Any thoughts? We are getting a 2500, 159 2300 PM hightop.

What questions were raised?
Aftermarket swivels add height, which I thought would be an issue but I just got used to it. If you are quite tall (view) or short (reaching pedals) you may need to lower the seat bases with aftermarket swivels. I'm 5'-10" and the height isn't perfect but fine enough for the past 25,000 miles of driving lol.

Also what did you insulate ceiling and walls with and are you happy with it?

I used Polyiso (I believe I mentioned that after Gary's post at the start of the thread). Totally happy with it, and good insulation. A bit of a pain to install (cut, cut, cut, glue, repeat 30 times, fill gaps with other product, cover ribs with another, etc.). But relatively simple, not too pricey, and insulates great. I think from what I hear that Thinsulate is the ultimate easy-to-install method.

Anything else really important you learned from your build? Sounds like it went well.

Yeah a ton of stuff lol. It went well, and I would not change much if anything even after living in it for 1.5 years.

I would give myself more space for the water system and just use crimp connections. I cobbled together various connectors and crammed them in. Have had a couple leaks and it's tough to work in there. But overall it's been doing pretty well for so much dirt driving all over the west and Baja.

I'd pick a different sliding door window. Probably do a bit more battery capacity. And would not use Renogy for the inverter. And I'd choose a hardwood for the cabinets cuz mine dent a bit too easy even though we are very careful.

But for the most part we are happy with all the products and construction methods. Nothing really falling apart except a couple water leaks, a bolt here and there to be re-tightened. Been pretty hassle-free.

 

I recently remodeled my water system. I too had a few minor leaks after much bouncing around on dirt roads. So I simplified simplified simplified. Now I just have a pump, a filter a small electric hot water heater and a sink. I use flexible sink connectors for all my PEX to sink, pump and filter. those things hand tighten and don't leak

I got rid of my gray water holding tank plumbing and ball valves and replaced it with a simple drain into a water jug which I remove each day and drain onto the ground.

I used thinsulate it was basically less than a day to insulate the entire van.

My Van came with the factory floor. I don't know if it's possible to buy that in the aftermarket but that would be worth a lot of money to do so. It's made of some incredible plywood that's waterproof and very strong. It's one piece with holes for the tie down bolts already located properly and finished with an plastic overlay.

I minimally insulated my floor partially because I don't believe it needs a lot of insulation (heat rises) and I'm also 6 ft and wanted the headroom. I find a fuzzy rug to be pretty warm regardless of the outdoor temperature.

@aaronmcd what is the issue with your inverter? One than size and noise, the 2kw inverter/charger has been a champ for me.

 

If headroom is at a premium you can lay a stiff floating floor directly on the foam board insulation. I was skeptical when it was suggested to me but the interlocking floating floor was stiffer than the 1/4” ply that I temporarily put down while I was working on the insulation.

We just have 1/2” XPS, heat film, and floating plank floor. It’s pretty stiff under my feet. I figure it’s not like you can fall through, there’s a metal floor under your floor! The entire floor is .75” thick and that left room for more insulation on the ceiling where it was really needed in out van.

 

If headroom is at a premium you can lay a stiff floating floor directly on the foam board insulation. I was skeptical when it was suggested to me but the interlocking floating floor was stiffer than the 1/4” ply that I temporarily put down while I was working on the insulation.

We just have 1/2” XPS, heat film, and floating plank floor. It’s pretty stiff under my feet. I figure it’s not like you can fall through, there’s a metal floor under your floor! The entire floor is .75” thick and that left room for more insulation on the ceiling where it was really needed in out van.

Hi, Thanks for responding. What is a heat film and what is a floating plant floor? What did you use for flooring.. brand name of wood? How did you make that work? Thanks!

 

This is what I used to heat the floor. It’s not for hearing the van, it’s just to keep the old Beagle happy and make the floor warm under your feet.

https://www.lowes.com/pd/QuietWarmth-36-in-x-120-in-Black-120-Volt-Underfloor-Heating-Mat/1000676299

Floating floors are the snap together planks that most houses have now. They are easy to install and don’t get glued or screwed to the floor.

https://www.lowes.com/pd/American-Heritage-Florian-Oak-8-03-in-W-x-3-96-ft-L-Embossed-Wood-Plank-Laminate-Flooring/1000766734

 

Good evening, I have a couple of quick follow up to help me sort out insulation. Will be using the polyiso. on a model year 2300, 159 2500 high roof-
How many sheets of poly approx. do you need for the walls and ceiling of 1" and .5 "?
How many sheets of xps for the floor and how many sheets of ply for subfloor?
For attaching the poly- some found it easier to use a 3m90 glue instead of great stuff to attach poliso. Do people agree? Will that fill in gaps around the outside edge of the insulation or do I need to use great stuff to avoid air gaps for condensation prevention? Thanks for sharing your expertise!

 

Glueing foambards to walls/ceiling

Hi Couple of questions re glueing Polyiso/XPS/EPS as insulation to the sheet metal: 1. Material: polyurethane foam spray (e.g. GS) is popular. question: would you recommend Sikaflex or Adhesive Spray (e.g 3M 90)? The problem with foam spray is that it expands and requires bracing. It's also a...

www.promasterforum.com

 

The number of sheets depends on how thick you want. I don't remember mine but maybe 3 for the floor, use leftovers on walls plus 4 or 5. 3M90 was sooo easy. One of the only spray adhesives that doesn't dissolve foam. Held great. I used spray foam in the gaps to insulate gaps and provide more hold. Just found 3M90 easy cuz no need to fabricate shoring to hold stuff in place.

 

Hi guys,
has any one heard of the flexible closed cell foam insulation? it says that it has and R value of 15 with sound deading features and vapor barrier.

 

Hi guys,
has any one heard of the flexible closed cell foam insulation? it says that it has and R value of 15 with sound deading features and vapor barrier.
View attachment 105321

Hi,
I would avoid it.

Its only 3 mm thick (0.12 inch). Very good insulations have an R value of about R6 per inch, so if this stuff is a very good insulation material (doubtful), its R value would be (0.12)(6) = 0.72.

So, the claimed R15 has to come almost entirely from the reflective face sheets.

Reflective layers do have an R value, but the reflective layer must face an airspace to actually get the R value. For this material, both the inside and outside layer would have to be spaced away from the van sheet metal on the outside and the paneling on the inside.

Another important factor is that to get the R value from the reflective layer, it has to stay bright and shiny. This link shows what happens to the R value of a reflective layer when exposed to a few minutes of heat and humidity.

Basically, its a scam.

Gary

 

I was reluctant to say the word (other thread), but yes, it is a scam. A very common scam because they know how much we wish it were true.