Bunk condensation

clyst

clyst

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I know this subject has been discussed before but I cant find it under "search"
My problem is as liveaboard some dampness/ condensation under bunk matresses.

There are no leaky windows etc so it must be due to cabin layout . The bunk top consists of two large ply panels on top of GRP moulding so the mattresses do not contact the GRP moulding . The cabin sides are double skinned and carpet lined . I seem to remember that IKEA sold something to put under bunk to ease the problem . any suggestions chaps ??

Cheers

Terry
 
We suffered from condensation under our aft cabin bunk mattress and have used the curved wooden slats sold by IKEA for their beds. It has certainly solved our problem of dampness under the mattress although we do also prop the matresses up when in port during the day to aid air circulation
 
Same here. I really thought it was a leak to begin with as it was so damp. But its just condensation.
I have a pingi thing from plastimo, which helped a while, but now in the depths of winter, with the heating on, the Pingi cant cope.

Crack a hatch open a little too - which allows some of the moisure out.

Id say try the Ikea, its bound to be cheaper than the marine solution - however it the marine bedding solution looks like it would do the job well. Or look at caravan accessories.

I too prop up my mattresses.

M
 
The caravan industry fixed this one many years ago - but strangely the boat industry has not picked up on it

The caravan solution was to replace the plywood bunk bases with strips of wood, held together by webbing to maintain the correct distance. Originally used for the pull out section to make the front beds into a double, the benefits were soon realised and used for the main seat sections also. This is easily replicated - though made easier in my case by purchase of a staple gun

The second part of the solution was then harboard panels atached with a slight air gap away from the sides of the caravan - to avoid the duvet getting damp from any condensation on the caravan walls. Slightly more complex to do for a boat, depending on the shape of the "walls" (ie hull) - also best not to drill holes to fix ;-)
 
we solved it by putting polystyrene under mattress for a quick fix then slats with felt carpet over.
when the boat is not in use we prop the slats up with a block to leave a big air gap solved it compleatly
 
Condensation Cures

Without doubt the biggest improvement that we've achieved has been sailing the boat around to the eastern Med and mooring it up there rather than North Wales. However, on a more practicable note we've achieved substantial (and in-expensive) improvements: -

Making a simple rain cover so that even in the wettest of weather, the forehatch can always be opened a bit.

Drilling 19mm holes at about 150mm centres through all of the plywood bunk bases and also through the doors into the lockers beneath.

Our best result came courtesy of an upholsterers cock-up a few years ago, when the new forepeak cushions got supplied slightly too narrow; to keep them securely in place we glued four dense foam insulation blocks about 30mm thick to the hull side as spacers. An unexpected benefit (the silver lining?) was that ever since, any condensation has trickled down the cabin side and into the bilge without touching the edges of the matress; we've been so pleased with the discovery, that the new berth cushions we're having made this week are being deliberately undersized (to the absolute amazement and utter despair of the Turkish Upholsterer) so that we can retain the feature.
 
Bunk Condensation

I have used the Ikea slats on my last two boats and also installed them on my friend's last two boats. I cut them to width (by trimming each side) for use in the forepeak berth; also cut the plastic "holders" to fit ply panels length so that I can lift the panel with slats without having to roll up all the slats first. They are (were) called "Sultan Liared" in the Ikea catalogue and come in at least two different widths and I.I.R.C. they cost about €20 a box.

They have worked well for me and is a very cheap solution.

Alan.
 
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I wonder if drilling some holes in the ply panels would allow enough air to the undersides to have an effect on the moisture level? And a vent to allow air into the space underneath. You might need so many that you'd fall into the space underneath though...
 
Having the base of the mattress covered with waterproof material seems to cause the problem. A small amount of trapped water becomes an issue. If the matress base is normal cloth, the problem seems to go away, although I did add a good number of vent holes in the plywood base as well. About 2 20mm holes per sq ft iirc.
 
clyst said:
There are no leaky windows etc so it must be due to cabin layout . The bunk top consists of two large ply panels on top of GRP moulding so the mattresses do not contact the GRP moulding . The cabin sides are double skinned and carpet lined . I seem to remember that IKEA sold something to put under bunk to ease the problem . any suggestions chaps ??
Click to expand...

Standard bubble wrap works very well. Put the bubbly side up and the smooth side down.
 
That's the PBO spirit!

Ubergeekian said:
Standard bubble wrap works very well. Put the bubbly side up and the smooth side down.
Click to expand...

Nice one - it's only the 3rd of January, but I think we have an entrant for "Post Of The Month".

I might try that as a quick-fix for 2.5 year-old daughter - she currently sleeps athwartships, on top of the fresh water tank - my first reaction on conducting a smell test was to think "Thank goodness! That's only condensation!"

I suppose reducing condensation by stikaflexing the crews nose & mouth isn't an option? :->
 
air

On my practical Day Skip we had a cabin each on a Bavaria 36(?). The tutor was adamant that even though it was cold (November) we should always sleep with ventilation or suffer condensation. My bag stayed dry with the porthole open, a companion got his very wet on night one but ok from then on because he left the porthole open.
 
There is an alternative to Drymesh that I have seen at the Southamton Boat Show each year. I can't spot it now in this year's catalogue, but it was there. The stuff looks like a cheap doormat, in a roll. It is an open network of fibrous appearance about 3/4ins thick and looks ideal for the job. As far as I remember it was a lot less expensive than Drymesh. I need some too but I can't find it yet. I will post if I do!

Mike
 
Wow thanks chaps for all your replies !!
All of them seem to have their merits but being a tight arse and that I have access to "large" size bubble wrap I will try that first and gradually work my way up the expence ladder.

cheers

Terry
 
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