Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
insulation and such and so forth
#11
(12-16-2017, 11:20 AM)bethiebugs Wrote: Is a specific vapor barrier necessary before any paneling? I wouldn't think a person could actually get something like a van interior to be airtight, but would it help?

How to make a inner vapor barrier in a van (and if it is even a good idea) is very much an open question.

My thinking is, that trying to make small pockets (buy using tape), will limit the free movement of dampness/vapor, so it travels much slower, or is limited to small spaces, if it gets into the wall material (or finds ways to stay trapped in between materials).

The idea of making only one main inner pocket in a van, does not make much sense to me. Foor one, it will be nearly impossible to make it tight enough.  And testing in buildings show, that double vapor barriers can give the effect that moisture gets trapped, and that can be even worse.

The metal of the van is one vapor barrier, and by adding another inner vapor barrier, one can easily end up with a vapor trap in sted.

So I don't think there is much evidence to recommend any one specific way, that will always work.


What is however well known, is that materials that can absorb water (like glass wool), when used as insulation in a van, definitely will absorb condensation. And unless it can be driven out (by heat and ventilation) within a rather short time after being absorbed, then mold will start forming.

So my thinking is, to try to limit what can seep/creap in-between  the metal and first layer of polyiso, by adding tape around the edges of the polyiso. But still make one small hole at the top and the bottom, so vapor gets a chance to escape once the van is in well heated climate again.


Likewise if using glass-wool, to do something to limit the direct exposure to moist or humid air, but to make a small hole at the bottom and top, so anything that does get in there, has a way out again, once the van is in a warm environment.

One of the challenges about making things water proof is; that water always tend to find some way in anyway, but the "water tight" makes sure that it will never find its way out again.

So even when making something water tight, it is wise to still plan for regular maintenance by some serious ventilation.


(12-16-2017, 11:20 AM)bethiebugs Wrote: Also, is insulation inside the small cavities/ribs needed? And would it help?

Again, a very good question, where I doubt there is evidence to support that any one way always works.
What ever can be done to limit formation of condensation (on the outer skin of the van) will however be a good idea. And once that has been made, then filling the crevasse can be a useful  idea, to increase the insulation effect.

(12-16-2017, 11:22 AM)bethiebugs Wrote: So when putting up the furring strips over the ribs, it would be best to use such insulating washers, correct?

Yes a washer (or other barrier) is always good between metal and wood (or metal and metal). 



But please note that my observations and insights are mainly from regular building traditions and general understanding of materials, and moisture issues in closed spaces. 

So try to also get input from other more van specific experienced people. Okay?
Add Thank You Reply
The following 1 user says Thank You to MrAlvinDude for this post:
bethiebugs (12-16-2017)
#12
(12-16-2017, 11:22 AM)bethiebugs Wrote: So when putting up the furring strips over the ribs, it would be best to use such insulating washers, correct?
Not needed for wood, but yes if adding steel to steel.

wrt vapour barrier of course the envelope as a whole can't be perfect, but I think it's worth trying for each section as much as possible.

keeping condensation from forming on cold metal is critical

So good active ventilation just as important
Add Thank You Reply
The following 1 user says Thank You to John61CT for this post:
bethiebugs (12-16-2017)
#13
Thank you all so much! I appreciate it greatly!!!!!
Add Thank You Reply
#14
My van system works really well compared to the other vans with nothing done about insulation. Insulated floor. Insulation between the vertical ribs. I used 1/2 foil faced poly with 3/4 inch purple poly as two layers. 1/2 inch foiled poly on the roof. The rib area does not make much difference. With any heat I do not have problem even at 30F. Propane or mains electric.
Add Thank You Reply
The following 2 users say Thank You to Weight for this post:
MrAlvinDude (12-19-2017), bethiebugs (12-16-2017)
#15
For any future reference, perhaps an elaboration on glass-wool and filling crevasse would be useful.

Glass-wool is a non-organic material, so it will not itself be broken down because of any organic procesces happening. This makes it very useful as a temperature insulation material, as it will easily continue to function, even if a dew-point is located within it, or close to it. 

A dew-point is where the water in the air, starts to form droplets (condensate).

Glass-wool will also stop easy movement of air, so it will limit how much moist air might get in touch with the outer skin of the car.
At low(er) outside temperatures, condensation happens quite fast on the inside of the outer layer of a van/car.

Filling crevasses in a van/car, with glass-wool will (significantly) lower the amount of air that can get close to the outer skin of the van/car.

So glass-wool in crevasse, does help with insulation, and it does help to lower the condensation happening on the skin of the van.

Glass-wool is however not air-tight (nor water tight), so small amounts of air (and vapor) will - over time - still get to the outer skin.  
The time frame will however typically have shifted from happening in minutes, to happening in days or weeks.


So, in my opinion, filling crevasses with glass-wool can be a very useful solution.


As a safety precaution, it may however be worth to check the status of the inside of the outer skin, every so often. To see if dust, spores (mold) has gotten a foot hold.   
Every so often, could be after every cold season, or something similar. 


This check (removal of the glass-wool to do visual and/or cleaning inspection) should mainly be done when the vehicle is in a warm climate, meaning when in a heated garage or when in warm weather.  
And more specifically, when the outer skin is above the dew-point. The dew-point is typically around 16*C (61*F).



What can also be done, to further limit the amount of air (and vapor)  that can even try to diffuse through the glass-wool (from the inside air, to the outer skin of the van) is to cover the inside of the glas-wool with a vapor barrier.


It should however not be made completely airtight, as this would trap any moisture that got in there, even when the weather got hot again, so a small hole at the top and the bottom, would probably be good.  

The goal is to allow for a 3 promille air exchange (is promille an english word? 1 promille = one 1/1000th). But for all practical intents and purposes; making a small hole, is what needs to be done. 





I hope this all makes sense, and will have practical value, so it becomes easier to chose what to do about those crevasses.
Add Thank You Reply
The following 1 user says Thank You to MrAlvinDude for this post:
bethiebugs (12-18-2017)
#16
I'd be wary of the tiny shards getting out, also I believe availability issues?

Rock wool is better known as being safely inert, no an irritant.

I like this stuff: https://www.fabricdepot.com/insul-bright-by-the-yard-45 used by crafters for DIY oven mitts.
Add Thank You Reply
The following 1 user says Thank You to John61CT for this post:
bethiebugs (12-18-2017)
#17
(12-18-2017, 01:44 PM)John61CT Wrote: I'd be wary of the tiny shards getting out,  also I believe availability issues?  

Rock wool is better known as being safely inert, no an irritant.

I like this stuff: https://www.fabricdepot.com/insul-bright-by-the-yard-45 used by crafters for DIY oven mitts.

That's is what I'm concerned with....could I really use the insul-bright? That's awesome! Would this work as well:

https://www.lowes.com/pd/Roxul-Wood-stud...-L/3388304

for filling the smaller cavities and such? Nothing seems to be in stores around here so I'm gathering options! Thank you!
Add Thank You Reply
#18
(12-17-2017, 10:58 PM)MrAlvinDude Wrote: For any future reference, perhaps an elaboration on glass-wool and filling crevasse would be useful.

Glass-wool is a non-organic material, so it will not itself be broken down because of any organic procesces happening. This makes it very useful as a temperature insulation material, as it will easily continue to function, even if a dew-point is located within it, or close to it. 

A dew-point is where the water in the air, starts to form droplets (condensate).

Glass-wool will also stop easy movement of air, so it will limit how much moist air might get in touch with the outer skin of the car.
At low(er) outside temperatures, condensation happens quite fast on the inside of the outer layer of a van/car.

Filling crevasses in a van/car, with glass-wool will (significantly) lower the amount of air that can get close to the outer skin of the van/car.

So glass-wool in crevasse, does help with insulation, and it does help to lower the condensation happening on the skin of the van.

Glass-wool is however not air-tight (nor water tight), so small amounts of air (and vapor) will - over time - still get to the outer skin.  
The time frame will however typically have shifted from happening in minutes, to happening in days or weeks.


So, in my opinion, filling crevasses with glass-wool can be a very useful solution.


As a safety precaution, it may however be worth to check the status of the inside of the outer skin, every so often. To see if dust, spores (mold) has gotten a foot hold.   
Every so often, could be after every cold season, or something similar. 


This check (removal of the glass-wool to do visual and/or cleaning inspection) should mainly be done when the vehicle is in a warm climate, meaning when in a heated garage or when in warm weather.  
And more specifically, when the outer skin is above the dew-point. The dew-point is typically around 16*C (61*F).



What can also be done, to further limit the amount of air (and vapor)  that can even try to diffuse through the glass-wool (from the inside air, to the outer skin of the van) is to cover the inside of the glas-wool with a vapor barrier.


It should however not be made completely airtight, as this would trap any moisture that got in there, even when the weather got hot again, so a small hole at the top and the bottom, would probably be good.  

The goal is to allow for a 3 promille air exchange (is promille an english word? 1 promille = one 1/1000th). But for all practical intents and purposes; making a small hole, is what needs to be done. 





I hope this all makes sense, and will have practical value, so it becomes easier to chose what to do about those crevasses.

Would something like Reflectix work as a vapor barrier over the rigid foam but under the paneling?
Add Thank You Reply
#19
Plain plastic sheeting makes a fine vapor barrier.

Shiny only blocks incoming radiant heat against glass or if you have extra thickness available to create an air gap, otherwise no point.
Add Thank You Reply
#20
I think rock wool is available as bulk filler as well as boards.

I would only use it for someone hypersensitive to plastics. I suspect it could retain moisture?

Note I think stuffing every crevice by hand may not be worth the trouble.

Key is a continuous envelope at enough R-value over all metal, not leaving any exposed to the living space.
Add Thank You Reply
The following 1 user says Thank You to John61CT for this post:
bethiebugs (12-20-2017)


Forum Jump:


Users browsing this thread: 1 Guest(s)

Powered By MyBB, © 2002-2018 MyBB Group.