condensation under the matteress

[ned]

We have a Hymer B Classic 544 which we are very pleased with, We do a lot of winter motorhoming in the Alps and throughout the year. We find that the underside of the mattress in the dinnette bed gets quite damp with condensation by the morning. We have tried a number of solutions but to no avail. We saw an advert for some special core matting to go underneath the mattress but at £50 a throw I feel this is a bit expensive. has anyone worked out acheap way of solving this problem?

 

Ned :-S :-S

[gordonaldson]

Good evening,

Think this has been a past thread.

 

Well the answer I would say here is because the mattress is warm on one side and cold on other, just like a single glazed window in winter time. Aaah that dammed droplets and condensation that you had to wipe off with a cloth. Or in the case of your front screen, 2 or 3 inches from the bottom.

The answer I would say would be either to heat the area below or the easier option ventilate it with vents. Just get rid of that cold air below.

 

Good luck,

Gordon..

[Brian Kirby]

I think the problem is that there is no ventilation under the mattress, because the dinette bed is not really intended for more than occasional use.  I think you'll find that Hymer regard the drop down bed - which current versions of the 544 have, so I'm assuming yours also has - as the main bed.  This has a mattress supported from a slatted base, which gives the necessary ventilation and should not suffer this problem.

The under bed lockers are relatively cold, so the condensation forms.  You will need to get ventilation under this mattress if you're going to continue to use this bed in cold conditions.  £50, relative to the cost of a B544, an Alpine holiday, or the cost of a new mattress, seems farily cheap to me - provided it works!

Otherwise, just use the van as it is designed/intended to be used, and you shouldn't have the problem.

[Guest Tracker]

Why not try any old cheapo or freebie carpet off cut for a start - and if it cures it or even just gets damp on the underside of the carpet instead of the surface of the mattress that will at least shift the problem to a more conveniently dried item than the mattress?

[Randonneur]

Try the rush beach mats. These were used quite a lot with caravanners who had the same sort of problems before slatted bases came into production and are very cheap to buy.

[Philman]

I made a pullout slatted section to fit between the seats, which were already slatted beneath the cushions. When not in use it slides back to the wall and acts as a small shelf. In use it has completely eliminated the condensation which used to occur when the underside of the mattress was solid. I stapled two lengths of inch wide thick black binding tape to the underside of each slat so that it would only pull out level to the seats at either end of the bed. I also put a couple of dowels in the seat frame and drilled corresponding holes in the outermost slat to stop it sliding back when in use.

 

Phil.

[Guest peter]

I had this problem in my rapido 710f and it was because the water tank is underneath. I got an domestic imersion tank blanket and put this all round the tank and cured it completely.

[locovan]

This is the problem when you have to use the table as a base. We had it in our Eldis so my husband made a slatted base which folded up when not in use and the problem was solved.

Mavis

*-)

[Guest Tracker]

A hard shiny surface like a table top will always cause more condensation than a less hard surface such as bare plywood, which in turn will always cause more problems than bare softwood.

 

I am not a physicist but I think it is to do with the softer surface having a better ability to absorb and disperse heat rather than reflect it as with a very hard surface.

 

Even a towel twixt table and mattress will help.

[Derek Uzzell]

ned:

 

I recall a recommendation that a couple of thick WOOL blankets placed between mattress and bed-base could help prevent condensation forming, but (even if it works) this ploy may be more expensive than using the coir matting you originally mentioned.

 

I was going to suggest that, if the bed-base is solid, you perforate it with a series of large holes to provide ventilation, but I note that the B-544 Classic's dinette bed incorporates the dinette table-top, so that idea's a non-starter! I chanced on a version of Mavis' temporary slatted-base idea on a yachting forum, where a modified B&Q plastic trellis had been used. (It was said to be effective but a bit cumbersome to set up and take down.)

 

You could try putting carpet under-felt under the mattress, or the foam-plastic membrane used between strip-flooring and a concrete sub-floor, or even a layer of thick bubble-wrap - anything really that will insulate the mattress from the bed-base. It's quite likely you've already experimented with these materials, as they are obvious choices, so you are probably stuck with forking out for the 'proper' stuff. As its normal use is in boats, it should certainly do the job in motorhomes.

 

As Gordon says, your question has been raised before:

 

http://www.outandaboutlive.co.uk/forums/forums/thread-view.asp?tid=5953&posts=14

 

The Ventair 15 product may no longer be marketed as I couldn't find a current supplier, but the rubberised coir stuff is still available from:

 

http://www.airflowsprings.com/

[ned]

Thanks Derek and all you guys. some of the suggestions you all make we have tried already. I take the point about the relative cost between van and underbed insulation but the reason we have been able to afford the van in the first place is that I am a tight old git who managed to save the money and spending £50 on the product slightly runs against the grain. Hey but I like the bubble wrap I could save money on heating by wrapping the missus up in it!!!!!

 

Ned

[Derek Uzzell]

Ned:

 

Nothing new about wrapping people in bubble-wrap. For some even more advanced ideas visit:

 

http://bubblewrap.tribe.net/

 

If you really get hooked on this, you may need a cooling system in your motorhome rather than a heater!

[trigrem]

You can get insulating ground mats from a camping shop, intended for Backpackers who use small lightweight tents.

I have used these successfully to insulate me from the ground when tent camping in below freezing temperatures.

I cannot comment on the present day price as mine is about 30 years old.

Another method I have used when tent camping in comfort using an air bed when condensation tends to collect between sleeping bag and the air bed is to use a wool blanket between bed and sleeping bag. You should be able to pick up wool travel blanket at a charity shop for a small donation.

Doug