Damp seating

Hi to anyone who might be able to shed light on this problem 


The horizontal cushion attached to the forward facing seat belted area /dinette of our van has a persistent dampness problem. It only affects the half of the seat away from the window side. Initially we thought that it might have been due to over zealous steam cleaning or a spillage of water during the valeting carried out before we collected the van from the dealer. We expected it to dry, and after using a fan heater a number of times, it seemed to improve, only to feel damp again once the heat source was removed. 
We searched the van for evidence of a leak, favouring the roof light. There is no sign of water damage in the fabric around the roof light,  and strangely, it is only one half of the seat that feels damp, with no spread to the other half adjacent to the window. 
There appears to be no sign of a leak in the floor under the seat, but the underside of the seat is perfectly dry anyway. We removed the seat by unscrewing it in an attempt to dry it in the house. Despite 3 weeks attaching it to a central heating radiator, the seat continues to feel dry until it is taken away from the heat! Its upholstery does have a slightly sticky feel.
I have spoken to some one from Autosleeper who has never heard of this happening before. He asked if it had been scotch guarded, but I am waiting to hear back from the dealer on that one. It crossed my mind that if water had got into to the cushion foam and then it was subsequently  scotch guarded, might it prevent any dampness being able to escape? A long shot but we are running out of theories. 
We'd be interested to hear from anyone who might be able to offer an explanation. 
Thanks,
Liz

Happy new year Liz, I cannot understand why your seat back cushion hasn't dried out, especially if its been inside for a period of time.
I take it you have the fridge vents located in position ? There is a substantial amount of draft comes in from behind the fridge, check out the sliding draw for rust on the metal parts on the inside.
I would avoid steam cleaning and high pressure washers,in my opinion they can do more harm than good , sealant distroyers.
Your cushions will feel cold and damp if the van isn't heated during very low minus temperatures.
Others will say vans do not require heating, its a personnel choice as I left my first A/S Symbol to freeze  7 years ago.
Boaby

PLOUGHLIN wrote:If it has previously been wetted with a salty solution, without removal of the salt it will become damp again after drying, when left in a cold damp atmosphere.

Fascinating answer. Salt solution can be used as stain remover especially for red wine, blood and ink. Perhaps a glass of red wine was spilt and therefore salt solution used. Let's not go down the possibility of blood stains.

That area that feels slightly sticky from the rest would more likely indicate a previous spillage/contamination of some sort. PLOUGHLIN illustrates the salt principle most clearly. Childhood memories of hanging a length of seaweed up to predict the weather. When the humidity rose, it would become soft and damp again from it's dried out state. Can you consider professional cleaning or replacement if it is annoying?

Thank you everyone and of course, happy new year. 
The salt suggestion sounds very interesting in that the problem appears to be resolved only to resurface once the seat goes cold again.
I feel that it might have to be unpicked to see what could be lurking underneath! 
Liz

Hi
   I put a dehumidifier in  my van for about 3 days and took out nearly 4 pints of water and I thought it was dry.Do shut all the vents.I did the same with my car it is surprising where all the water comes from
Regards
Alan