What insulation have you used for hull and cabin roof?

[FullCircle]

We want to start combatting condensation and improve efficiency in the heating or heat reflection in the boat, but there are many issues.

We can put sheets of insulation in the saloon headlining panels, and use something from waterline to seat level, but beyond that it is not possible to remove the furniture modules (easily).

In the forecabin we have an injection moulded GRP overhead, and fixed teak veneer lined sides with a small gap behind above mattress level , so even less opportunity.


At the moment, I am looking at 6mm Plastozote aluminium backed sheets and have looked at a spray application of expanding foam that seems quite well controllable.

We are in Uk now, but will be liveaboard and heading to Netherlands, France and then the Med in the next 3 years, so there are very different climates to consider

Can you let me what insulation you have used? How good is it/bang per buck etc?

 

[Yngmar]

My hull is foam cored above the waterline and most of the deck. Some areas (cockpit coaming) are not cored, and only those areas and the ones below the waterline (not cored either) suffer from condensation, the cored areas do not. I've recently installed some 6mm foam (camping insulation mattress) in some of the under-seat lockers a short while ago, but haven't had enough time to see if this works - I'll find out when it gets colder and the water temperature has dropped (probably February). But since the cored areas are seeing no condensation (UK south coast), I would conclude that 20mm closed cell foam (the coring material) is totally sufficient (ok, perhaps not if you're planning on spending winter on deception island).

As for applying it, I used hot glue, drawing small lines on the back of the foam before slapping it on the (acetone wiped) flowcoat of the inner hull. This sticks well enough and they don't come off, but unlike any spray glue/foam, you do not have a hell of a clean up job if you ever want to remove the foam again for any reason - pry up a corner and give it a good tug and it'll come off in one piece.

The other thing that helped immensely was fixing every last tiny leak on the boat (I've got some assistance from last years winter storms, where whole waves flew over the breakwater wall and landed on deck - great way to find every last leak while you can't sleep anyways :dread. Does wonders in reducing cabin humidity too.

Or you could just hurry up and sail to warmer places and trade your condensation problems for ventilation ones

 

[FullCircle]

My hull is foam cored above the waterline and most of the deck. Some areas (cockpit coaming) are not cored, and only those areas and the ones below the waterline (not cored either) suffer from condensation, the cored areas do not. I've recently installed some 6mm foam (camping insulation mattress) in some of the under-seat lockers a short while ago, but haven't had enough time to see if this works - I'll find out when it gets colder and the water temperature has dropped (probably February). But since the cored areas are seeing no condensation (UK south coast), I would conclude that 20mm closed cell foam (the coring material) is totally sufficient (ok, perhaps not if you're planning on spending winter on deception island).

As for applying it, I used hot glue, drawing small lines on the back of the foam before slapping it on the (acetone wiped) flowcoat of the inner hull. This sticks well enough and they don't come off, but unlike any spray glue/foam, you do not have a hell of a clean up job if you ever want to remove the foam again for any reason - pry up a corner and give it a good tug and it'll come off in one piece.

The other thing that helped immensely was fixing every last tiny leak on the boat (I've got some assistance from last years winter storms, where whole waves flew over the breakwater wall and landed on deck - great way to find every last leak while you can't sleep anyways :dread. Does wonders in reducing cabin humidity too.

Or you could just hurry up and sail to warmer places and trade your condensation problems for ventilation ones

Must admit I have just had some sun awnings made for the saloon roof that attach to the stackpack, as I want to reduce sun load for daytime use also. Hence the insulation in the headlining panels

 

[ChattingLil]

as you know, we were lucky enough to inherit OL already insulted with celotex. After three winters (that long already!) I can happily say that we have no problems with condensation at all. Apart from in the hatches, but this was cured by my home-made double glazing (wooden push fit frame fitted with cling-film). We do use the dehumidifier a couple of times a week through the coldest periods.

The added bonus is that our boat is significantly cooler than our neighbours' through the occasional heatwaves too.

Not sure how feasible that will be for FC.

 

[FullCircle]

as you know, we were lucky enough to inherit OL already insulted with celotex. After three winters (that long already!) I can happily say that we have no problems with condensation at all. Apart from in the hatches, but this was cured by my home-made double glazing (wooden push fit frame fitted with cling-film). We do use the dehumidifier a couple of times a week through the coldest periods.

The added bonus is that our boat is significantly cooler than our neighbours' through the occasional heatwaves too.

Not sure how feasible that will be for FC.

Thanks Lisa, what grade/thickness of celotex?

 

[sailorman]

Thanks Lisa, what grade/thickness of celotex?

As thick as space allows Jim. our house walls have 90mm within the timber frame & on the sloping ceiling sections 135mm is the min to conform to regs ( here in England)
check generic types that will do the same job cheaper

 

[FullCircle]

As thick as space allows Jim. our house walls have 90mm within the timber frame & on the sloping ceiling sections 135mm is the min to conform to regs ( here in England)
check generic types that will do the same job cheaper

I have about 10mm Roger......

 

[sailorman]

I have about 10mm Roger......

10mm is better than nought, Is the deck hd egb/ foam or solid.
Ventilation is the key to low condensation, i think the Carib cruisers have similar probs due to being battened down in heavy rain in humid conditions

 

[Bru]

I plan to use at least one layer of foil / LDPE wrap type e.g Thermawrap (it's approx 3.7mm thick and comes on rolls 1m wide and 7m long for about £25) with a minimum of one layer across the timber battens with plastic washers to prevent the headlining screws crushing it*. Between the battens I'll use an appropriate thickness (probably 10mm but 6mm is also available) of closed cell foam insulation widely sold for insulating vehicles

* This won't entirely eliminate thermal bridging but it's the best I reckon I can do without going to extremes

 

[heart of oak]

Have you looked at the thinsulate marine products.....i seem to remember a chap on the tv insulating a narrow boat with it ......like a foil backed fleece...

 

[Bru]

Have you looked at the thinsulate marine products.....i seem to remember a chap on the tv insulating a narrow boat with it ......like a foil backed fleece...

I couldn't find anything thinner than 19mm

 

[duncan99210]

We found that the key to reducing condensation to a minimum is ventilation rather than insulation. Using the ebersbacher for heating draws fresh air in from outside the boat, pushing out stale air: we usually kept at least one washboard out to provide a good exit path into the cockpit tent. The heater was run on the basis of full heat for about an hour before turning off for an hour and so on, rather than trying to run it on the thermostat at a lower temperature. That stopped it clogging up with soot.

Friends on a similar sized boat started off using fan heaters/electric radiators and had serious condensation problems. They tried insulation using some of the ideas above but found them to be ineffective. They fitted a blown air heater (think it might have been a Webasto) and resolved their condensation problems overnight, hence why I consider the real solution to be decent heating and ventilation rather than insulation.

 

[shan]

You need a combination of both. Insulation will help limit the heat loss and make your heating efforts that much more effective.

 

[Bru]

You need a combination of both. Insulation will help limit the heat loss and make your heating efforts that much more effective.

Indeed and when you'v got thin headlining glued directly to the underside of th deck (as per our forecabin) no amount of heating or ventilation is going to cure the condensation!

 

[wully1]

I used cheap camping mat bought from Decathlon.

thin with good insulation, I glued it to the deck head and hull sides then re fitted the lining- it was thin enough that I could re use all the same screws.

If you have a newer boat with moulded in everything you might not be so lucky..

 

[Tim O]

I'm trying a combination of the aluminium-backed bubble wrap stuff against the hull followed by two 10mm layers of closed cell foam where I can fit it in between the battens. I'm then putting the lining panels on top of this having taken the old foambacked vinyl off, scraped off the decaying foam and replaced it with selfadhesive underlay for laminate floors.

I'm sure there'll be lots of little gaps, and this is only for the hull sides in the sleeping cabins right now but best I can do in time for moving aboard in January....yay!

I'll tackle the deck head when I summon up the energy and money!