Got a van!

[yamatama]

Hi! We got our first van 2016 ProMaster and just started the simple conversion project so that we can bring the van to camping and surfing. We just finished sound dampening and about to start insulation.  As we live in northwest, the main concern is keeping the heat in, but it would be nice to prevent heating too much in hot summer days (the van is dark gray).
  
We are planning to use foil sided polyiso foam on the wall and ceiling.  I saw some posts mentioning that an air gap between the foil side and the wall increases the R-value as well as preventing heat coming in.  We are debating having the air gap or just gluing the polyiso on the wall/ceiling.  Is it worth the time/effort and taking up the space to warrant using an air gap?  Any advice is appreciated!

 

[Joseph_Grey]

Hey congratulations on the purchase! I am at about the same point with my van. What I am thinking of doing is glueing the polyiso to the side rails of the struts. I think that will leave about 3/8" air gap on most of the sheet. What I have read is the foil gets you an additional 2 of R value. So instead of 7 per inch it is 9. But you will likely get other info on here, perhaps more accurate than mine!

Again, good going on the build!

--joe

 

[eDJ_]

Welcome to the CRVL Forums    

Hope you will be ready by nice weather.   I'm sure having a Van will be an endless source of fun
for you no matter where you go.  And when you get on the road you'll meet others to compare
rigs with and learn the features they have built into theirs and the benefits of them.  This will give
you more insights for refining yours. 

All the best !

 

[Every Road Leads Home]

Congrats on the new set of wheels! It's an exciting time indeed. Look forward to following the build. I'm not sure the best answer to your insulation question. I think any insulation is a huge improvement and vent fan even more important.

 

[highdesertranger]

Welcome yamatama to the CRVL forums! To help you learn the ins and outs of these forums, this "Tips & Tricks" post lists some helpful information to get you started. We look forward to hearing more from you. highdesertranger

 

[akrvbob]

You have three choices, 1) glue directly to the wall between the ribs and 2) glue/screw a whole sheet to the ribs the length of the wall, 3) do both. I'm doing a van build right now, and I am doing both. If you insulate between the ribs but leave the ribs exposed, a lot of heat will flow through the ribs and out in the winter and in during the summer--the ribs are a thermal bridge transporting heat in and out. Better to take a 4x8 sheet of polyiso and run it the length of the wall and it will cover the ribs as well as the wall. However, you will lose that much interior space. But I think it is worth it and the best way to do it.

If you are going to panel the walls/ceiling, the foil side should go toward the van sheet metal. The ribs will act to create the air gap and the foil will help greatly to keep summer heat from penetrating the van.

Doing both by putting polyiso against the wall between the ribs and over the ribs is the best possible way to do it, because it doubles your insulation and eliminates the thermal bridge.

 

[yamatama]

Hey congratulations on the purchase!   I am at about the same point with my van.   What I am thinking of doing is glueing the polyiso to the side rails of the struts.   I think that will leave about 3/8" air gap on most of the sheet.   What I have read is the foil gets you an additional 2 of R value.   So instead of 7 per inch it is 9.   But you will likely get other info on here, perhaps more accurate than mine!  

Again, good going on the build!

--joe

Thanks Joe! I was thinking something similar to your idea.  I was wondering if I should put something between the side rails for a little more support, like additional rails made of polyiso strips.  Or plywood coverage on top of it may be enough for support.  A lot to think about but it's fun

 

[yamatama]

Thanks Bob for the great advice! I never thought of doing both "against the panel" + "cover ribs with air gap".  For the single layer approach I was thinking 1" for the wall and 2" for the ceiling.  If I go with this "both" approach, what is the thickness of polyiso you'd recommend for the wall and ceiling?  About a half of single layer thickness x 2 layers?

 

[akrvbob]

I don't deal with much cold, so I'm not putting much in. On the roof I have 1 inch of polyiso between the ribs and 3/4 inch spanning the ribs. That's about R-11.

On the walls I have 1/2 inch on the walls and 1/2 inch spanning the ribs. That's about R-6.5 The silver side is facing toward the van walls and there is a 1/2 inch air gap so I think that will help with summer heat.

The paneling will go on the interior side of the insulation making a sandwich and will be screwed into the ribs.

I should have videos of this part of the build going up next week.

 

[dr_nelson]

(...) On the roof I have 1 inch of polyiso between the ribs and 3/4 inch spanning the ribs. That's about R-11.

On the walls I have 1/2 inch on the walls and 1/2 inch spanning the ribs. That's about R-6.5 The silver side is facing toward the van walls and there is a 1/2 inch air gap so I think that will help with summer heat. (...)

Where on earth can I buy polyiso boards? Lowes and Home Depot currently don't have them in stock 
(I am in SC)

And are Polyiso boards and Polyisocyanurate boards the same?

 

[CautionToTheWind]

Yes <B>dr_nelson</B>, the same.

I'm sure you can order them direct from local box store.