Carpet on fiberglass ceiling? Condensation?

[Naio]

Hi folks!

My new van has a fiberglass high top, lined with carpeting. I am wondering if I should tear out the carpet and just paint it.

This would be a lot easier to do now, in the build stage, rather than after the interior is finished and I am actually camping in the van. But that means I cannot experiment, so I am hoping to learn instead from you all's experience instead.

I've done most of my camping in deserts. But I spent part of this past winter near the Oroville Dam -- a humid climate all the time, and crazy wet this year. And I might go back.

The thing about that climate is it is humid and TEMPERATE-- about 65 in winter. So I really don't want to run a OR heat, either of which would dry things out a little.

My current van has a carpeted floor. (No, not shag! Stock automotive floor stuff.) I keep it covered with plastic mats, but this winter had endless problems with condensation under the mats.

This convinced me of the importance of a non-permeable floor in the new van. But how will carpet behave on the ceiling?

Clearly it will absorb condensation, and then dry out as circumstances permit, ideally daily. And it will add some insulation. But in areas with poor air circulation (storage), will the ceiling carpet stay damp, and mold like my flooring did?

What if I have just a painted fg ceiling? In humid cold weather (no ac) will there be enough condensation to drip or run? That would also be onto storage areas.

I sure could use some info from you folks, especially any with fiberglass shells. What does your rig do, and in what climates?

[doxiemom11]

We have carpet on the ceiling of our 2000 motorhome and don't have a problem. We do however take the chill out with an electric heater and if it gets below 60 inside, run the furnace a cycle or two to bring the temp up. Maybe you could get a small dehumidifier. Many of us use them when we are in damp climates.

[Naio]

Mex, do you get cool nights? Do you have any trouble with condensation between the outer shell and the space blanket? Have you looked in there?

My background is in S&B construction, so my thinking may be a bit off, but I am leery of impermeable layers. I am used to thinking that vapor has to be able to travel through the layers.

That said, I have seen no problems in my old van, which has stock assembly of closed cell foam (loosely stuck onto metal roof), air gap, then fiber headliner with sprayed on thin foam and thin fabric. There could be mold in there I don't know about, though

[dclark1946]

Casita Travel Trailers has been building their fiberglass trailers for years with carpet (plush with foam backing for extra insulation) on the ceiling and walls for many years. We never had any issues with it on ours even in the rainy Smokies.

[MEXICOWANDERER]

Naio, in my toad out comes headliner and insulation and in goes extra thick space blanket shiny side up then a perforated fabric headliner material. Air transfer is the only true guaranteed solution. Quicksilver has an inch and a half of insanely expensive micro pore foam up down and sideways. But I still need to dehumidify when I spend long periods of time inside. Cooking overwhelms every attempt. Furniture is connoly hide leather and finish is solid teak. Building the bus I knew the tropics was going to tax my best efforts.

[Naio]

So, areally you folks saying I should rip out the carpet and replace with headliner fabric?

How thick is this headliner fabric? If thin, I would prefer paint. Or is it thick enough to provide some tempetature/sound insulayion?

[Tyler0215]

Automotive headliner fabric is sold by the yard. Spray glue and careful trimming and cutting is needed to fit the fabric to curves.

[jplante4]

Ozite

[Cobra21]

We have the carpet type headliner in our '93 class C and it is still very nice.
I vote to keep it!

[Naio]

@Tyler: I had the mats out for weeks and still could not get the floor carpet dry.

What do you mean headliner? I am used to that meaning a molded, multilayered foam-and-fiberboard panel, custom fit to each model of car. But it sounds like you mean something else? Maybe something good?

[Lwiddis]

I'm anti-carpet floor or...lol...ceiling. I'm pro throw rugs....washable (and replaceable) throw rugs.

[Tyler0215]

The carpet on the floor got moldy because moisture was trapped under the mats.
Carpet without a foam backing will be OK on the ceiling. Or use automotive headliner.