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I'm doing a combination of rigid and spray foam. How do people deal with thermal bridging on the exposed metal? Do you not worry about it? Do you cover every bit of metal? Are people concerned about covering the van wiring? What if you have problems later on?
 

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I used about a half a can of spray foam in total while insulating for this very reason. Yes, I would be very concerned about burying all my wires in spray foam!
 

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My wires run in the usual ribs and channels but most of them had rigid polyisocyanurate inserted FIRST. And yes it is tough to do those with rigid board. Now I have access to all my wiring by removing the factory interior panels. I covered the interior of those ribs with factory covers or wood strips on the ceiling to get some thermal break. We are at about R-10, Oddly you may not want to over insulate if you have heat like an Espar or Wabasto as they need to run not short cycle. We calculated the heat loss to let our Espar diesel heater run on low at 30º F as below that we run it at night when asleep. It has worked perfectly. More insulation would have forced it to shut down and restart which is much noisier and wakes us. See GaryBIS’s insulation calculator:
http://www.builditsolar.com/References/Calculators/VanHeatLoss/VanHeatLoss.htm
 

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I'm doing a combination of rigid and spray foam. How do people deal with thermal bridging on the exposed metal? Do you not worry about it? Do you cover every bit of metal? Are people concerned about covering the van wiring? What if you have problems later on?
I plan on getting ducting wrap (I believe is what the folks on here have called it) for the ribs etc. It's a thin adhesive insulation foam type material. I will not be covering up the runs of wires to any point of causing a problem of future work in there. Maybe put in a type of polyester filling in those areas that could be removed or moved if needed.

If you haven't done this already or plan to, I think you'll lose more out the front of your van than those ribs unless you get yourself a good insulated curtain or insulate the cab and use a insulated windshield and window covering. Any curtain makes such a huge difference that we have a cheap one in there currently from my previous Transit connect and the cab cools a million times easier and faster in this crazy heat than without some kind of barrier. It doesn't even come close to the floor. I'll get around to a new one soon. This time insulated and with a fashionable interior side sewn onto the black insulated outer side.

Sent from my SM-G930T using Tapatalk
 

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For the ribs I cut reflectix and inserted them in through the sides and then covered the ribs with a foam insulation tape. Its not perfect but it has some insulation. I did run some wires through the ribs but they can be removed.

For us we covered as much of the inside of the external sheetmetal as possible with a sheet insulation. For any metal parts inside that we had insulation between it and the outside, we just covered it with fabric. The plus to this is that you can use heavy duty magnets from Home Depot to mount things.
 

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Insulating the rocker panels

We're doing Polyiso/Great Stuff on all major panels and also Thinsulate in areas as needed. Regarding the photo -- these slots in the rocker panel are pretty deep and mostly below the floor level -- it appears water runs through here as well -- how did you folks insulate this area --- cut and trim polyiso like the rest of the van? Stuff with Thinsulate? Did you stay off the bottom a 1/2" or so for drainage?

Thank you.

 

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I didn’t much. No spray foam for sure as the drains must be kept clear. You might cover it to eliminate the conduction. Much if it will be behind cabinets too.
 

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I'm doing a combination of rigid and spray foam. How do people deal with thermal bridging on the exposed metal? Do you not worry about it? Do you cover every bit of metal? Are people concerned about covering the van wiring? What if you have problems later on?
While I also did polyiso and foam, I have since been converted to a full believer in Thinsulate. While the cost seems greater up front, I have since calculated the difference and it is negligible. I also feel that the time savings would have been worth the cost as well.

With that said, I installed my polyiso and foam first, then ran fishing line through the ribs after. It was a bit tough in some parts to get the line around rounded corners in the rib system, but I now have clean channels throughout the van to run wires. There is no issue with foam "sealing" the wires in place since it had time to cure before running the line. You can see what I mean in my build thread.

See the left, horizontal rib channel of this image to see what I mean. The fishing line sits on top or tunnels through the existing foam or polyiso.


I hope that helps.
 

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Polyiso from Home Depot - foil covering

I purchased some of the Polyiso 1" from Home Depot -- it has the foil on both sides. I cut a few panels out just now and noticed the foil backing comes off easily and has peeled back a couple of inches on the two pieces I just cut.

Did any of you remove the foil from the van skin side of the board before Great Stuff'in it so as to get better adhesion and not worry about the foil pulling away from the foam even more down the road?
 

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It is not a problem. Cut clear through so you don’t rip it free and when you Great Stuff glue it put a few small beads vertically up the back then when it is cured apply some on the perimeter. Trust me it will stay! All foams seem to absorb moisture and you do not want to remove the foil as it is the guard against that.
 

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I'm doing a combination of rigid and spray foam. .... What if you have problems later on?
Have you seen the photos of warped skins on spray foamed vans? Body shops hate spray foam.
Suggest you consider Thinsulate(TM) which is acoustic/thermal insulation engineered for vehicles.
Rigid foam is going to seal in moisture whereas Thinsulate will allow it to dry out.

 

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Forget sprayed on foam. It's expensive, messy and unless done very correctly will cause a mess as the photo Hein posted. Go with thinsulite or foam boards with LOW expansion spray foam (Great Stuff Door & Window, for example).to fill in the spaces.

Most newbies totally overdo things like insulation and sound deadening because they don't know any better and don't believe those who know better. The old adage "If a little is good, more is better" is your enemy.

I won't even get into discussing how most people (including me) make all sort of changes after their conversion is completed. If you spray foam the whole van you will need a big paddle to get back down that creek sooner or later! ;)
 

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Yea, I hate that creek. To know HOW MUCH to insulate see GaryBIS’s calculator. There is a sweet spot where your cooling or heating loss is controlled and thickness and cost is optimal. I wanted my Espar heater to run on low (most quiet) at 30º and so I put in insulation to get the right amount and you know what? It worked. More would have cost more, used up more space, and my heater would have short cycled all night. Same issue if you install AC. Overdo at your peril.

See: http://www.builditsolar.com/References/Calculators/VanHeatLoss/VanHeatLoss.htm
 

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Hi,

My van is insulated with spray foam, but if I had it to do over, I'd use the polyiso adhered to the van skin with Great Stuff Pro.

But, the spray foam is fine if you want to use it.
Its very easy to spray it so that it does not distort the van skin -- just use multiple thin coats. I can see how pro spray foam outfits that have not done vans before could get this wrong and spray a thick coat on. But, pro spray foam outfits that do vans regularly or DIYers can easily get it right.
It will insulate well, NEVER squeak and be trouble free, and it will never let water vapor get to the cold van skin and condense there (nor will polyiso done correctly).
I'm not sure that in the end it takes any more labor to do the spray foam than to do the polyiso, but it is more expensive and a little harder on the nerves.

The spray foam has not gotten in my way at all as I've made changes to the van. For example I added the maxxfan after the spray foam. It took 5 minutes to remove the foam in the fan area -- its just not a big deal.

The spraying process is not that difficult, but you want to get your ducks in order so that you can spray the van with minimal interruptions. Masking is important. Having the bottles all set and at the right temperature is important. This is a detailed description of how I did my van -- I'd never done one before, and it came out fine. It was kind of fun to learn a new skill :)
http://www.buildagreenrv.com/our-conversion/our-conversion-insulation/

Gary
 
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