Insulation, is damp a problem?

[Cuiken]

So, I'm lining our Kombi for use as general purpose daytrip/adventure van. Read every post, watched every video and decided on the fairly standard approach:

1. dodomat butyl sound deadening on panels
2. Foil back thermal/acoustic foam on top of dodomat (had a few issues here, damned stuff keeps peeling off)
3. Fill the remaining voids with polyester 'fluff'
4. Carpeted panels back on with hidden fixings

Having insulated old buildings in the past I'm very mindful of creating damp issues by reducing airflow inside the panel voids. Is this a real problem or am I overthinking it?

As a a nod in this direction I have not used any polyester fill in the lower voids of the sliding doors or at the bottom of the side panels or tailgate. The hope is that any moisture finds its way down there and then has enough airflow to evaporate.

We're not sleeping in the van so I'm also guessing the AC will reduce humidity.

Any experienmce on this?

Ta

 

[DXX]

Search ‘dew point’ on the forum.

 

[Long tall John]

Get some window deflectors on your front doors. It means you can leave the front windows open 2 inches each side without the rain comming in. It gets rid of an off a lot of moisture.

We also have our van soundproofed and insulated and it doesn’t seem to be a problem. Had the van 2 years now and we don’t even have a pop top for extra ventilation they give.

 

[Cuiken]

I've had a good look over the dew point posts but these all seem to focus on camper conversions. This is just a day van/huge car. So, nobody sleeping inside and, generaly, engine and aircon running when we are inside.

Why all the insulation then? Basically I can't help myself. I want it to be quieter and warmer/cooler on long drives.

Ta for suggestion of window deflectors. I'll see what I can find.

 

[DXX]

You’ll just have to breath through one of these extended with some hose.
If campers don’t have issues neither will a day van.

 

[Cuiken]

You’ll just have to breath through one of these extended with some hose.
If campers don’t have issues neither will a day van.
View attachment 129604

I've always wondered what those snorkels on the side of chelsea tractors were for! They help avoid damp.

Cheers

Yeah, I'm probably overthinking all this. Classic case of getting half way through a job and then panicking that you're doing it wrong...

 

[nimrod]

So, I'm lining our Kombi for use as general purpose daytrip/adventure van. Read every post, watched every video and decided on the fairly standard approach:

1. dodomat butyl sound deadening on panels
2. Foil back thermal/acoustic foam on top of dodomat (had a few issues here, damned stuff keeps peeling off)
3. Fill the remaining voids with polyester 'fluff'
4. Carpeted panels back on with hidden fixings

Having insulated old buildings in the past I'm very mindful of creating damp issues by reducing airflow inside the panel voids. Is this a real problem or am I overthinking it?

As a a nod in this direction I have not used any polyester fill in the lower voids of the sliding doors or at the bottom of the side panels or tailgate. The hope is that any moisture finds its way down there and then has enough airflow to evaporate.

We're not sleeping in the van so I'm also guessing the AC will reduce humidity.

Any experienmce on this?

Ta

how did you get over the acoustic foam peeling off, I have used dodo mat everywhere and now want to stick the next layer to it, thinking of underlay, its 8 mm thick and quite dense so should be very similar if it will stick ok, I only use as a day van. also thinking of dodo on the inside of arches and sticking carpet to that, trying to find out if that will stick.

 

[Cuiken]

I switched over to using dodo acoustic foam. No more issues. The first stuff I tried was from a different manufacturer and the foam was very stiff and the adhesive inadequate. The upshot was it peeled off all over the place.

Switched to dodo stuff and it all worked perfectly. No peeling issues even on the roof.

 

[Loz]

The only way to stop this is to insulate the voids and then have a vapour barrier on the inside, then panel. That's because polyester/sheep's wool etc is breathable and the moist air will eventually get through to the cold skin and condense.

 

[nimrod]

The only way to stop this is to insulate the voids and then have a vapour barrier on the inside, then panel. That's because polyester/sheep's wool etc is breathable and the moist air will eventually get through to the cold skin and condense.

when you talk about voids, are these the obvious ones between panels and metal work or the areas behind shaped metalwork, also would you need the vapour barrier if near all but 100% 2mm dodo stuck to metalwork.

 

[Loz]

The aim is to stop the warmer moist air from touching a cold surface. If the dodo insulates well enough then moisture won't condense on it, and as it is waterproof it is also a vapour barrier in itself. It may not be practical to fill the shaped parts so you can tape them up so moisture doesn't get in there.

 

[nimrod]

The aim is to stop the warmer moist air from touching a cold surface. If the dodo insulates well enough then moisture won't condense on it, and as it is waterproof it is also a vapour barrier in itself. It may not be practical to fill the shaped parts so you can tape them up so moisture doesn't get in there.

great that's how I understood it, but wasn't sure about the shaped parts. thanks