SPRAY FOAM INSULATION: Why I won't use it

[TMG51]

we would throw chunks of the hard closed cell foam boards into our water troughs.  this would keep the suns rays off the water to control algae growth.

Pretty ingenuous. What industry was this? Agricultural?

 

[highdesertranger]

yes on our cattle ranch. highdesertranger

 

[cognitive dissonance]

here's another unscientific observation.  we would throw chunks of the hard closed cell foam boards into our water troughs.  this would keep the suns rays off the water to control algae growth.  this foam did not seem to absorb water and some were in the troughs for 20 years and more.  also the foam cups that coffee and soda comes in,  if they would absorb water then they would leak.  highdesertranger

I've seen this done here in Colorado, by the horsey set. In the summer, it's to suppress algae growth. In the winter, it's to help the tank heaters keep up with really cold temps...

While they will never sink, the foam boards gain water weight over time. I know this firsthand from taking care of a lady friend's horses when she was out of town.

(I was reminded of this years later, when I learned that the insulation industry doesn't warrant the R value of this product over time due to moisture absorption.) 

In the conditions Bob described (rain for 2 weeks straight, in and out of the van several times a day with wet clothes, sleeping) there is no doubt polystyrene foam board insulation will absorb moisture. 

Of course, bedding, paper products and clothing will absorb even more moisture, and that is annoying enough that you might never notice your walls are damp too. Particularly if the insulation is covered up...

 

[VJG1977]

Links to info on foam insulation water absorption.

Resisting Water Absorption, the Key for. High Performance Foam Plastic Rigid Insulation. PDF 954KB

Expanded polystyrene (EPS)
insulation (Figure 3) is comprised
of polystyrene beads fused
together under heat and pressure.
Although the beads themselves
are closed cell and hydrophobic,
the air spaces between the
beads allow water and air to
penetrate the board structure. 

Polyiso Insulation and Water Absorption:  PDF 125KB  

A material’s resistance to water vapor is determined by testing the
product via ASTM E96, a measure of water vapor transmission. This
method produces permeance ratings, or perms. Typically, polyiso foil-faced
sheathings have perm ratings of less than 0.3, which is 3-5 times better
than common extruded polystyrene products. For this reason, polyiso is
the best insulation for cavity wall applications. Designers are advised to
determine the optimum thickness of polyiso by performing a dew point
calculation for the system.

PublishedLiteratureDOWCOM PDF 316KB

Several manufacturers promote
mineral wool insulation as an
appropriate insulation for use in
rain screen cavity walls. However,
when basic water absorption
tests are performed on a standard
mineral wool product, it absorbs
water readily, and the absorbed
water takes days to drain from
the insulation. While it is wet,
mineral wool insulation has
reduced R-value (RSI)*

 

[VanKitten]

So, now I am back to looking at Ecofoil.

So..what do I use to keep the foil away from the metal walls of the van? I read that the aluminum will cause corrosive reaction with that metal.

 

[Almost There]

So, now I am back to looking at Ecofoil.

So..what do I use to keep the foil away from the metal walls of the van?  I read that the aluminum will cause corrosive reaction with that metal.

To create a dead air space you can use bubble wrap.

There are different grades of bubble wrap so search out the thickest you can find.

I cut the panels of reflectix to fit the cavities between the walls and then applied the bubble wrap to the 'outside' of the cut panel with 3M Super 77 glue. The combined panels were then taped in place with metal tape.

 

[akrvbob]

I disagree, you're back to using polyiso which is the very best thing you can use.  

Did you read this above:
"Typically, polyiso foil-faced sheathings have perm ratings of less than 0.3, which is 3-5 times better than common extruded polystyrene products. For this reason, polyiso is  the best insulation for cavity wall applications."

Bob

 

[TMG51]

I disagree, you're back to using polyiso which is the very best thing you can use.  

Did you read this above:
"Typically, polyiso foil-faced sheathings have perm ratings of less than 0.3, which is 3-5 times better than common extruded polystyrene products. For this reason, polyiso is  the best insulation for cavity wall applications."

Bob

I agree... polyiso and be done with it.

 

[VJG1977]

The big thing that I got from this is how the water absorption test is done.  

For example, the material standard that defines
properties for all XPS and EPS is ASTM C578.1
It requires that polystyrene insulation be
tested for water absorption in accordance with ASTM C272.2
C272 requires the polystyrene sample to be immersed in water
for 24 hours, and weighed immediately upon removal from
immersion to determine the amount of absorbed water

The primary concern with water absorption in home building is when the foam is buried next to a foundation wall.  
 
How many years of normal use in a van wall would it take to match that exposure?  

I believe any expanded polystyrene, extruded polystyrene or polyisocyanurate unfaced or foil faced will work fine in a van.  I may have missed it but has anyone had a problem with any foam other than open cell spray?

 

[GotSmart]

The big thing that I got from this is how the water absorption test is done.  

For example, the material standard that defines
properties for all XPS and EPS is ASTM C578.1
It requires that polystyrene insulation be
tested for water absorption in accordance with ASTM C272.2
C272 requires the polystyrene sample to be immersed in water
for 24 hours, and weighed immediately upon removal from
immersion to determine the amount of absorbed water

The primary concern with water absorption in home building is when the foam is buried next to a foundation wall.  
 
How many years of normal use in a van wall would it take to match that exposure?  

I believe any expanded polystyrene, extruded polystyrene or polyisocyanurate unfaced or foil faced will work fine in a van.  I may have missed it but has anyone had a problem with any foam other than open cell spray?

I spent the night in January at  rest stop in Kansas.  I woke up with a 1/4 inch of ice on my window by my head.  I can imagine what spending a week in a cold climate would do to the insulation.  

Polyiso and foil tape is inexpensive.  Especially compared to the cost of having a professional spray foam in the van.

 

[Milk Hauler]

The transport industry tranports our food in trailers using rigid type insulation. Supposedly its a different kind of foam impregnated with anti-microbial chemicals.

I've toyed with the idea of taking a 53ft reefer trailer for $15,000 and making the worlds most insulated camper. There is a trucker who did just that. Only problem was shoring up window cutouts. Apparently these trailers are designed to flex going down the road. Not good for glass.

Talk about boondocking in Alaska or Death Valley! [emoji12]

Sent from my SCH-S968C using Tapatalk

 

[glworden]

I am the OP.

The polyiso is looking like a reasonable choice.

I have received some wool samples and have been assured that the wool is benign. There are different ways of treating it and the Wikipedia article only refers to one.

I agree from experience that foam can take on moisture. I used a two-part spray foam mix to fill bow and stern of a kayak, thinking I would have impervious flotation. The foam got saturated with water and is now very heavy. Maybe I didn't use the right stuff - but I am no expert.

For those still interested in wool as insulation, check out The Living Bus. They have a facebook page and a website with lots of pictures of their insulation procedure. They used a low VOC adhesive and applied a thiin layer of cork right to the metal wall. Then blown in wool insulation behind a paper fabric to hold it in the cavity. Their experience is that the wool absorbs and releases moisture and regulates their environment well. They heat with wood rather than propane because propane does add moisture. This is a real world example of wool insulation in a metal vehicle with people who have researched it and who are there to answer questions. The cork is an interesting idea and also worth considering.

For those saying that foam IS a vapor barrier, and that you will always add moisture to a small van while sleeping and just being in it, where does the moisture go? I guess you vent it out. Probably same with wool.

If there is a consensus here, what is it? Polyiso? Sprayed foam? Wool for us tree huggers?
Gary

 

[akrvbob]

It might be interesting to set up a poll and ask people "Based on your experience, which is the best insulation for insulating a van?" But, ask anything you want to ask.

I'm not sure if you can do it or not, if you can, go to the bottom of the page and on the far left are some options I think everyone can see them. The bottom option is "Add a Poll to this thread."

If you don't see it, and want me to, I will sit it up for you. Just decide what you want the choices to be.
Bob

 

[glworden]

It might be interesting to set up a poll and ask people "Based on your experience, which is the best insulation for insulating a van?" But, ask anything you want to ask.

I'm not sure if you can do it or not, if you can, go to the bottom of the page and on the far left are some options I think everyone can see them. The bottom option is "Add a Poll to this thread."

If you don't see it, and want me to, I will sit it up for you. Just decide what you want the choices to be.
Bob

Go ahead, Bob, and do a poll if you want.   

It sounds like people have strong opinions about this and some are more justified than others.   The top candidates in my mind are the polyiso, foam (sprayed) and wool.   I started out thinking Reflectix, but now not so much, since I now understand that it is a radiant barrier rather than insulation.  I also don't understand how the aluminum on the reflectix might react to the metal wall of the van or to adhesives.  Not knowing that, I don't want to take that chance.

If I have learned anything for pretty much sure, it is not to use the GREAT STUFF foam, and I hope anybody who is considering that looks into the problems.

Cognitive Dissonance says he has a lot of experience and has done a lot of research.  I think he favors foam.  True?

I hope some of you will look at the Living Bus website and Facebook page.  I find their project intriguing.  Is there anybody on THIS page who has used wool insulation?  Several have shared experiences about wool blankets and things in the army, but I don't think anybody has mentioned actually insulating with wool.

What I am most likely to do at this point is to make wool battens in fabric cases and hang them temporarily along the walls.  See how it works before I do anything permanent.  I am looking to travel and camp for a few weeks at a time, mostly following the good weather, and not full-time in a van.   We have an NV-200.  Small.  As we look into thing, we are leaning towards low tech.  No battery system.  Rechargeable solar lights, little butane stove, Rtic cooler and port-potty.   If I were full-timing, I would probably get more elaborate with electrical system like some of you.

When you are full-timing, what are some of the places you refill water?

The NV-200 is too small, but in general, do any of you add gray and black tanks, or just use portas?

Thanks.