Insulation Question/Need Help

[WanderFil]

I bought my Promaster with the walls sprayed with insulation (see attached pic). There would still be space between the insulation and where the wall (most likely cedar where visible and plywood where it isn't). 
Should I fill those spaces with more insulation or not? 
If yes, what insulation should I use?

I will most likely do the ceiling with thinsulate or rigid insulation.

Thanks for the help!

 

[highdesertranger]

I wouldn't mess with trying to add more. just do the ceiling like you said. highdesertranger

 

[John61CT]

How thick is it, and how many weeks per year will you be boondocking in sub-zero temps?

If you go with Thinsulate that would be easy to add between the foam and the liner.

Definitely get some over the metal bits at least, thermal bridging sucks the heat right through.

 

[WanderFil]

How thick is it, and how many weeks per year will you be boondocking in sub-zero temps?

If you go with Thinsulate that would be easy to add between the foam and the liner.

Definitely get some over the metal bits at least, thermal bridging sucks the heat right through.

That's a good question, not sure how thick it really is. I guess I'll have to measure in the morning.

I plan on taking it up to ski resorts in Cali and Colorado, so their definitely will be some cold nights.

Should I use the Thinsulate inside the actual bridging?

How about vapor barrier? yes/no?

 

[Technomad]

I think the ribs maybe should be covered or they will be a gap in your system. Thinsulate inside them might be enough.


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[MrNoodly]

Air gaps are a useful part of insulation. Don't worry about it.

 

[SoulRaven]

Has anyone heard of anyone using High Temp hot glue?
Ize just wondering.

 

[Almost There]

The problem with any type of hot glue is that the softening point is far below the melting point.

When the glue softens, the parts being adhered tend to slip. The glues work well, even when exposed to high heat when you're dealing with a horizontal surface but when you're working with a vertical surface like a van side - well not so much!

There are better adhesives for the job than hot glue.

 

[SoulRaven]

The problem with any type of hot glue is that the softening point is far below the melting point.

When the glue softens, the parts being adhered tend to slip. The glues work well, even when exposed to high heat when you're dealing with a horizontal surface but when you're working with a vertical surface like a van side - well not so much!

There are better adhesives for the job than hot glue.

Makes good sense. I was more curious if anyone had used it.
On a side note, my countertop in galley, I use those DAP sticky dots to hold things in place, like coffeepot or other things. Those work very well in heat & cold on flat surfaces.

 

[John61CT]

Yes for boondocking in the snow you really want to maximize.

Stuffing ribs can use cheap packing foam if you don't have enough leftover thinsulate. Consider getting a small box kit of the two-part foam to fill in any big gaps if you run out of thinsulate, or use it instead, cheaper I think. Post for more caveats if you go that route.

Air gaps don't have much value at all compared to real insulation, only suitable for S&B walls with 6-8" there already.

Definitely insulate **well** over any metal not thermally isolated from the outside body work.

Total R-values should be a ratio like 2:3:4 floor:walls:roof.

Yes to the vapor barrier, 6mil dropcloth + the right tape, last layer before your interior lining, luan or whatever.

 

[SoulRaven]

Yes for boondocking in the snow you really want to maximize.

Stuffing ribs can use cheap packing foam if you don't have enough leftover thinsulate. Consider getting a small box kit of the two-part foam to fill in any big gaps if you run out of thinsulate, or use it instead, cheaper I think. Post for more caveats if you go that route.

John's 2 Part Foam insulation - http://www.uscomposites.com/foam.html
I plan on ordering it for my Fall "Fun" finishing insulation job.

 

[Canine]

Like John61CT said, get rid of those thermal breaks. Those will suck soooo much heat energy out of your van.

Since space is at a premium in my trailer, for the roof I used 1/2 inch polyiso with fiberglass facing. Most often you see polyiso insulation with that shiny, silver, foil face on both sides. Then I painted the insulation with a high quality latex primer and paint. It took the paint extremely well and the paint made the already strong facing more durable. This polyiso also has a very high compression rating; it is so hard it's more like Sheetrock than rigid foam insulation. It was purchased from a roofing company for $25 per 4X8 sheet. It can't hold a screw at all, but it does maximize space while providing a durable wall that can be bumped into or scraped without damage. Very durable, nice looking surface. As long as you don't plan on attaching anything to the insulation itself, it works well.

 

[SoulRaven]

Thank you Canine, You brought up some interesting ideas. I'm pondering them now.

After posting the 2 Part foam, I did lot of reading at the FAQ's on how it's to be used. It is a pour type and sets up fairly solid within ~45 sec. So, I'm not sure yet on how I'd use it effectively to get it on walls or ceiling since it's pour type. 

I've a few months before I'm to finally decide then commit to the What to Use & How To's. I have some materials already. Still need to make decisions.

 

[Canine]

To clarify: The roof has 4 total inches of polyiso with the last half inch that fiberglass faced rigid foam.

And filling in the middle of the support ribs won't help. I really, really wish I could find that test I saw online where it tested metal tubing filled with spray in foam insulation and how well that helped. It didn't. Not at all. The conductive metal tubing sucked that heat energy out much too quickly. It was only when they covered it up so the heat wasn't directly touching the metal tubing did it make a difference. Not the results I was expecting, and they said the same in their test.

However, filling it up I would think would keep condensation from forming and that would have big value.

 

[John61CT]

Yes filling the tubes would be a low priority, but will help make things quiet too.

Covering **over** any exposed metal a high priority.

If using that pourable stuff, be **very** careful you don't deform your sheet metal "mold" - just a little at a time and always give it an escape path as it needs to explode.

I actually meant **spray** in this case, filling gaps or covering steel in the walls and ceiling. Dow and other vendors have two-part kits of 2# foam, quantity measured in "board feet" but expansion is very dependent on temperature.

The one-part Loctite or Great Stuff is not as good, but OK for final touchups if buying another whole box of the pricey stuff would be wasteful.

 

[SoulRaven]

John, would you consider making a separate thread with steps on how to use the best foams, separated out for the various "base" foam used alongside the other cheaper foam, as fill in foam rather than waste a full package of the 2 part? And what foams are those best to use, including a how to best to use the pour in foam?

It could be where no one else comments, until you state you're finished with the thread, or threads. 
Reason I ask, is there are too many threads already with only bits and pieces of info. Most don't have the time to sort through the numerous threads to gather full info. 

I did gather info, and still do, while I ponder my final insulation plans to occur this fall. Insulation is my primary goal for my van at this time. I'm somewhat leaning toward using the DOW 2 part Spray foam. 
Monday I'm phoning DOW Foam Solutions @ 1-866-583-2583 pick Option 4 for DOW FS Building Team & Technical Support.

 

[Technomad]

Definitely insulate **well** over any metal not thermally isolated from the outside body work.

Yes to the vapor barrier, 6mil dropcloth + the right tape, last layer before your interior lining, luan or whatever.

This is the challenge I’m facing. The ribs are like 2” into the vehicle envelope. Filling the large gaps with insulation is fine, but am wondering how to isolate the ribs (which have a direct thermal connection to the outside van wall.). I can fill them with insulation, and thermally isolate them from the interior structures, and I guess I can give up an inch in that process and fill it with insulation.

Can you tell me what you mean by “6 mil dropcloth” for a vapor barrier? Is that just the plastic sheet you commonly see for covering a floor while painting? How about Tyvek? Is it a better vapor barrier?

Insulation is one place where I’m happy to spend money.



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[Technomad]

John's 2 Part Foam insulation - http://www.uscomposites.com/foam.html
I plan on ordering it for my Fall "Fun" finishing insulation job.

Is this the stuff that everyone told me not to use because it would cause the van sides to bulge out? (I’m only planning to use it on gaps where it is free to expand inward without resistance and so should put no pressure on the van wall.


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[Technomad]

Since space is at a premium in my trailer, for the roof I used 1/2 inch polyiso with fiberglass facing.

Looks like this is what you are describing (only thicker.

https://www.menards.com/main/buildi...8633-c-5779.htm?tid=129892189103678393&ipos=9


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[John61CT]

Yes that Menards version has some extra puncture resistance with the glass facing rather than just foil.

I've thought about using it for a "standie foamie" shell without needing any other inside lining.