There are other advantages to the fully ply lined van also.
Camper van roof lining.
This is a professional 7mm sound and heat insulation material for a quieter and warmer van camper van or motorhome.
Carpets panel trims headlinings etc the trim fix high temperature.
This will prevent any water vapour not ventilated making it.
You can achieve a better level of insulation in the van by batoning out the shell fitting thicker insulation in the van and then plying over the insulation.
Many camper conversions add a vapour barrier over the top of the insulation and before lining the walls and ceiling.
When choosing the best campervan roof vent for your setup consider.
The 7mm liner is a thermal equivalent to 100mm of glass wool.
Your camper van insulation and ventilation is integral to the comfort level of your van life.