Condensation beneath mattress - any solutions?

[Kangaloosh]

Hi,
The outboard half of our main bunk lies over a water-tank, which gets cold in winter, and after a night asleep there is condensation on the plywood beneath the mattress and the mattress is wet. The inboard half, which lies over two drawers full of clothes, is fine.
We have tried "Thinsulate" (Heavy-duty bubblewrap with a coating of aluminium foil) without success.
Has anyone solved a similar problem? If so we would be delighted to hear your solution.
Thanks in advance.

 

[Mirelle]

Replaced plywood bottom board with iroko slats. There is about a one inch air gap between slats and top of s/s water tank.

No longer live aboard, but I did this mod. when I did and it worked fine - still works, actually!

 

[Das_Boot]

I stopped wetting the bed mattres dried up quick. Secret is not to go to bed drunk.

 

[paulineb]

IKEA sell wooden slats which are bowed in the middle and fit under the mattress so that the air flows freely. we have them and they work perfectly.

 

[snowleopard]

You must create a gap between the mattress and the bunk board. Wooden slats work, so does rubberised coir matting (Natural Mat Co) or plastic mesh (Hawke House). A DIY solution is to get plumbers' plastic foam pipe insulation, slit into semi-circular section strips and glue them to the bunk board at intervals of a few inches.

Those solutions that involve a ventilating layer inside the mattress still allow the bottom surface to get wet.

 

[BrendanS]

There are no end of expensive solutions available at the boat shows. Personally, would go with Mirelles slats as both cheap, practical, and most effective.

The other thing to consider is ventilation, as without this, you'll always get condensation. The more vents you can put in (to both cabin, and anywhere under berth, the better)

 

[Sea Devil]

Drill holes on the floor beneath the mattress - it is a problem of air flow

 

[BobOwen]

Drilling holes will not let air flow. It will only ventilate that plug of mattress covering the hole won't it? Whats also needed is an air gap to let the air flow ie: raise the mattress slightly off the surface.

The IKEA slats, as mentioned, are perfect, adjustable, trimmable for awkward spaces and sell at around £8 a set (Single section). They are almost identical to the "marine" version which retails at around £80. (Don't you just get sick of marine prices)

This will solve the problem!

 

[fudge]

Try a product called Ventair 15, has worked wonders for us. A quick google will find suppliers.

 

[Roberto]

there is a sort of plastic artificial lawn which is perfect, the base is all perforated and the plastic grass leaves are stiff and dense enough to keep the mattress horizontal

you can also play golf while at anchor -.<z)

 

[smee]

Victoria Star bed kit from Victoria Yachting provides a superior solution to the problem, with star shaped heavy duty plastic springing rather than boring oneway sprung slats and elevates the mattress 2 inches approx for easy air flow.

 

[tcm]

airflow will work, tho insulation eliminates the problem altogether - a post a while ago where the solution was to uise that blue "builder's board" as used in the air gap in building house walls was cut to shape and placed under the mattress.

 

[Grehan]

The plasticy open weave birds nest stuff is hugely expensive. We used cheap expanding trellis from B&Q and it worked very well, except awkward to get out the way when one wants to get something from the locker underneath.
Ikea slats look like a great idea.

 

[pragmatist]

Which slats did you use, Pauline ? There seemed to be a wide variety.

And did you need to cut them ? Our berth is tapering and whichever size we chose would need tailoring and I'm not sure how - we're a long way from an IKEA so its difficult just to go and look.

 

[Anonymous]

We bought the expensive slats from the London Boat Show from Natural Mat Company. We are very pleased - very heavy duty and make the bed far more springy, almost like a decent home divan. Haven't looked at the IKEA slats so can't compare. Anyway, the cure is near 100% though as liveaboards, in the coldest part of the winter, there was still slight condensation though not enough to cause any problems.

 

[Anonymous]

You cut the Natural Mat Company's slats to suit. I used a junior hacksaw, holding the slats onto the teak handrail using a toolmaker's clamp. Very easy provided you measure it up carefully and take your time. Took me half a day for a very large double - I used two kits. The NMCo. slats and rubber 'binding' is very heavy duty - they support quite heavy people and there are no problems even if one is not entirely motionless all night /forums/images/graemlins/smile.gif

 

[pragmatist]

Thanks for that - sounds nice and easy. However the huge difference in price between IKEA and Natural Mat Co. makes me want to investigate IKEA first - I think we would need about £20-£30 of slats from one and about £190 from the other !

 

[Anonymous]

I had heard about the IKEA slats before going to the Boat Show and, like you, had intended to check them out but we had no local IKEA and when I saw the contentes of the NMCo pack, it looked like fair value for money so I rather assumed that you get what you pay for. I could be wrong, though, and I'm sure it is worth checking out if you can do so without too much trouble. Let us know how they compare; I have another couple of bunks that I would like to do. I'm quite sure that slats are the way to go and the NMCo slats are lovely and springy, holding the mattress nearly an inch off the base. Don't consider them as merely an anti condensation device.

 

[ianabc]

Hope someone can help with this ....

So are the slats 10 cm X 12 cm hardwood?

And are they laid flat on the ply or under matress surface?

 

[Anonymous]

[ QUOTE ]
So are the slats 10 cm X 12 cm hardwood?

[/ QUOTE ]Each NMCo slat is, in cross section, 36mm x 8mm and are as long as the width of a large single bed (don't remember the figure).
[ QUOTE ]
And are they laid flat on the ply or under matress surface?

[/ QUOTE ]When the slats have been cut and inserted into the special 'rubber' strips that hold them together you end up with something that lies neatly on the locker top, immediately under the mattress. It rolls up neatly when you need to access the locker. The mattress is placed on top of the slats in the same way that you place a mattress over any normal bed base. Because the slats are held together by heavy-duty rubber strips, they do not move about; the whole thing is a sound professional solution that is suitable for everyday use.