[keeponvaning]

Don’t sweat it!

 

[HarryN]

Harry, what fascinates you about those materials?

So of course the effects of insulation, condensation, heating and cooling all can push the concept of optimizing is various directions.

The aspect that I like is that if the slicker / spacer materials are in place between the wall and the insulation, there is an increased chance that the water will have a chance to either drain down or evaporate out of that space vs collect in the insulation.

I have seen in the past how challenging it can be to dry out a vehicle that has had water spilled inside during cold and rainy seasons. I am leaning toward the idea of using a low temperature dehumidifier for colder seasons.

 

[RDinNHandAZ]

Or use an insulation that does not absorb moisture like foil covered polyisocyanurate. It is slicker itself!

 

[RnR]

I think that if people are experiencing conditions in their van where water is running down their walls, they probably should create drain passages in the wall structures and the floor wells (because there are none) and not insulate against the wall but rather panel over the ribs and leave the walls hollow to allow all this water to run down the walls.
I also think they should add small roof vents along the sides of the roof, to allow all this moisture to evaporate from inside their walls.
Or,....just insulate properly and fix whatever is causing all this water to run down your walls. Most likely a roof leak.

 

[keeponvaning]

Better yet park in a garage?

 

[RV8R]

So of course the effects of insulation, condensation, heating and cooling all can push the concept of optimizing is various directions.

The aspect that I like is that if the slicker / spacer materials are in place between the wall and the insulation, there is an increased chance that the water will have a chance to either drain down or evaporate out of that space vs collect in the insulation.

I have seen in the past how challenging it can be to dry out a vehicle that has had water spilled inside during cold and rainy seasons. I am leaning toward the idea of using a low temperature dehumidifier for colder seasons.

@HarryN

Thanks for clearing that up.

So I’m not 100% familiar with “slicker”, but I believe RnR got it wrong (that yellow product looks to me to be a 3/8” rainscreen drainage mat not a foundation drainage mat which a common product is called dimple board )

Rainscreen Mat;

Driwall™ Rainscreen 10mm | Building Envelope | Keene Building Products

www.keenebuilding.com

The purpose of the drainage mat or skyrim is to hold off the exterior wall finish from the waterproofing layer on the exterior sheathing of a building.

In a van that is easily achieved without this drainage mat by simply installing the rigid board insulation with vertical adhesive beads to ensure a 3/8” airgap.

RnR does make a valid point regarding a continuous vertical drainage path to lowest rocker drain holes. I suppose if one was ultra worried about this small drilled water collection relief holes could be performed prior to insulating.

When I built, I ran thru the logic of total spray vs rigid and choose the rigid with an airspace between the van skin & rigid. I also sealed my rigid as well as I could. I also built with plywood finished panels which is a vapour barrier (albeit not continuous, still will catch a majority of interior environment condensation), & most importantly build with almost no mould food in my structure cavities (2 small treated plywood backing for fan & shore power - but that was it). My interior surfaces are mostly sealed plywood.

If I get migrating interior air behind my rigid insulation I hope it to be a minor amount, for it to drain if condensates, & not cause mould spores to grow.

I do not see why a DIY van builder would use “Slicker”, but maybe I am missing something? Please let me know if you think I have missed the point.

edit; If what GaryBIS did “total spray job” actually stops the condensation issue & the R value is acceptable & the spray does not creat separation & thus voids between the metal van skin, & the chemicals don’t kill you; then I think it is the better option until we find a better one. These are my current thoughts on this topic.

 

[HarryN]

@HarryN

Thanks for clearing that up.

In a van that is easily achieved without this drainage mat by simply installing the rigid board insulation with vertical adhesive beads to ensure a 3/8” airgap.

If I get migrating interior air behind my rigid insulation I hope it to be a minor amount, for it to drain if condensates, & not cause mould spores to grow.

I do not see why a DIY van builder would use “Slicker”, but maybe I am missing something? Please let me know if you think I have missed the point.

I get your point, but I am really not wanting to go through the effort of installing a rigid insulation. As a result, I need something else to deal with the interface of an inside steel wall and the (not sure yet exactly what) but flexible insulation. Probably won't use thinsulate but will be something flexible, at least in those numerous gaps.

Thanks for the info on the drainage mat - will look into that as well, but many of those types of products off gas when they get hot.

 

[RV8R]

I get your point, but I am really not wanting to go through the effort of installing a rigid insulation. As a result, I need something else to deal with the interface of an inside steel wall and the (not sure yet exactly what) but flexible insulation. Probably won't use thinsulate but will be something flexible, at least in those numerous gaps.

Thanks for the info on the drainage mat - will look into that as well, but many of those types of products off gas when they get hot.

I get it ... I edited my post above. Consider a total spray job like GaryBIS ?

 

[SteveSS]

Don't forget insulation is not the only tool for controlling condensation. Active humidity management is just as important. Just two people breathing raises the humidity inside such a small enclosed space. Add cooking and showers and you quickly approach monsoon conditions -- unless you also practice active dehumidification (A/C) or ventilation! Having no A/C, we rely on ventilation with fan and windows. And yes, in colder climates that requires extra heat. But we try to find the best balance between the two. Always a work in progress. A humidistat helps us keep an eye on it.