cabin insulation

[Jack B]

hi,
does anyone have expierence of sleeping in a small GRP boat against the cabin sides with no wooden slats added or similar. Is the condensation there as well as cabin roof
Thanks Jack

 

[G12]

If it's cold outside then you will get condensation. I had a wet sleeping bag last winter where I'd touched the hull in the night.

 

[maby]

I would agree - for comfort you really need to line all the bare GRP surfaces with something like short pile carpet...

 

[Simes]

Hi Jack, expect condensation to be just about everywhere. Even at this time of year you need to have insulation and ventilation.
The wooden slats are just to allow an air gap this gap provides both insulation (albeit not very good and ventilation (again not very good).

A layer of closed cell foam would make a big difference to your life onboard. We used the cheap foam mattresses sold in camping and hiking stores. These we trimmed to fit and stuck in place with impact adhesive. Once in place we then used sticky backed cloth over the top to provide a warm touch and pleasant colour.

Overall effect? Terrific, boat warm and dry, crew warm and dry. Ventilation just means leaving a hatch slightly open.

Hope that this helps.

Simes

 

[floebs]

A layer of closed cell foam would make a big difference to your life onboard. We used the cheap foam mattresses sold in camping and hiking stores. These we trimmed to fit and stuck in place with impact adhesive. Once in place we then used sticky backed cloth over the top to provide a warm touch and pleasant colour.

Hi Simes, this is just what I was looking for too, and a great idea! Thanks for the tip!!

Do you line surfaces below (inside saloon lockers etc) aswell as on the easy access surfaces in the forecabin and saloon?

I have a 27ft and am looking to move onboard, but until I work out how to get the condensation down a little, its not looking favourable!

 

[Bobobolinsky]

I've insulated my boat with Celotex, it's available in 12mm, 20mm, 25mm, 50mm
The difference is impressive to say the least. I had one forrard bunk insulated at a time. So still sleeping on an uninsulated, while the other bunk insulated, what a relief to be insulated and it's not expensive. Can be "glued" with poly sulphide or instant foam. Board out on top or apply carpet.

 

[bobgarrett]

You should consider carefully whether you are actually reducing condensation or just hiding it by having it soaked up by something. Condensation on a waterproof surface can be soaked up with a sponge the next morning and disposed of; condensation soked into some carpet will still be there but cannot be removed. Hence the boat will be damper inside for longer. You only really cut condensation by insulation, and probably lots of it.

 

[floebs]

I've insulated my boat with Celotex, it's available in 12mm, 20mm, 25mm, 50mm

Is that the rigid stuff? Does it score easily to allow curvature?

I like the idea of tackling one sleeping area at a time... and to the possibility of a toasty nights sleep!!

I'm trying to stay away from using carpet tho, seems to be a vast differing of opinion when it comes to carpet lining onboard, my personal feeling is I'd rather use mainly non absorbant insulation, if at all possible.

Thanks for the advice tho - thats really helpful!

 

[V1701]

Cork (tiles), foam-backed vinyl, van lining carpet (e.g. here), foil-backed bubblewrap which is then boarded over are other options. Insulation, ventilation and dry heat are key. Have an electric blanket as well and maybe something under the bunk (drymat or ikea slats cut to size)...

 

[Bobobolinsky]

Is that the rigid stuff? Does it score easily to allow curvature?

I like the idea of tackling one sleeping area at a time... and to the possibility of a toasty nights sleep!!

I'm trying to stay away from using carpet tho, seems to be a vast differing of opinion when it comes to carpet lining onboard, my personal feeling is I'd rather use mainly non absorbant insulation, if at all possible.

Thanks for the advice tho - thats really helpful!

It's rigid foam, in a short length of hull it conforms easily to the curvature. I''ve put 25mm on the hull, up to waist height, covered in flexible 3.6mm faced hardwood board, above that is Vee tongue and groove. The deckhead is insulated with 20mm (didn't want to loose the extra headroom) and covered with 3.6mm board

 

[floebs]

Cork (tiles), foam-backed vinyl, van lining carpet (e.g. here), foil-backed bubblewrap which is then boarded over are other options. Insulation, ventilation and dry heat are key.

Wowsers! So much to choose from!!!! The foil backed bubble wrap looks interesting - I'm considering insulating the saloon roof area too as its only single skin GRP - so the bubble wrap might do the trick for that!

Do I need to lightly sand/rough up the surface (of the GRP) for the adhesive to actually stick to the surface? I'm thinking I'd probably have to sand, wipe down with spirits, and properly dry off before applying the glue - would that be sufficient prep?

Thanks for all the input, and sorry for hijacking this thread - I havent worked out how to post a new thread yet!!!

 

[dmmbruce]

Ventilation!

I know it has been mentioned on several posts, but can I suggest that ventillation is very important.

I had well insulated walls but streaming condensation sometimes. I fitted permanent ventilation and the problem vanished.

Also, the areas that seemed permanently wet all dried out in less than a week and have stayed dry.

Mike

 

[dleroc]

I am in the process of lining out the ceiling of the cabin because the previoulsy fitted thin carpet was peeling off. I have decided to stick 3.5mm plywood battens across the ceiling. It is essential to ensure the ceiling surface is clean for the adhisive to work. Even so I have screwed the battens to the ceiling (double skinned GRP) as they weren't staying in place with the curvature of the ceiling. I have now cut out about 6 peices of 3.5 mm ply which is now screwed to these battens. I am going to remove the plywood panels and bring them home to seal and cover with the foam backed vynil material that is on sale at Dunelm Mill. The reason for the 6 removable panels is to cope with any future need to route any more wiring.
At the moment the lower sides of the boat have the thin carpet and it is both dry and still firmly in place.

I don't intend to put the panels in place until next Spring to avoid any winter problems. Will it work - just don't know but it's an interesting job to keep me occupied during retirement!

 

[onesea]

My boat came with plywood to keep you form the hull and condensation what we do is put against that the cockpit cushions (1 1/2" foam).

They are the type you pickup at Boat jumbles cheap and cheerful but you notice the difference in the night if you lean against the hull of a night.

The rest of the boat is unlined we have plenty of ventilation (top hatch board out just a canvas curtain), when its cold there is still plenty of condensation on the bulkheads etc...

 

[graham]

Hi Jack, expect condensation to be just about everywhere. Even at this time of year you need to have insulation and ventilation.
The wooden slats are just to allow an air gap this gap provides both insulation (albeit not very good and ventilation (again not very good).

A layer of closed cell foam would make a big difference to your life onboard. We used the cheap foam mattresses sold in camping and hiking stores. These we trimmed to fit and stuck in place with impact adhesive. Once in place we then used sticky backed cloth over the top to provide a warm touch and pleasant colour.

Overall effect? Terrific, boat warm and dry, crew warm and dry. Ventilation just means leaving a hatch slightly open.

Hope that this helps.

Simes

Great idea and I think the 99p shop in our highstreet sells them. Off to spend several 99 ps tommorow iof they still have them

 

[CET1]

Try Airtec Double Insulation 1.05 x 25mProduct Code: 21112
from Screwfix we are gradually working through our boat now. starated with cutting panels for the windows and hatch as trial and that made a big difference

 

[davidej]

Ventilation is MUCH more important than insulation.

You can't get away from the fact that we breathe out several literes of water a day and in a confined space this will lead to humidity greater than 100% and condensation.

Leave a door/ hatch/window open when you sleep in a cabin, however well insulated it is.

 

[RogerG]

If you understand the reasons for condensation, then you are half way there to reducing it. Since buying our current home, a 57x10 steel canal boat, I have learned a lot about condensation in a never ending quest to stop it

A given volume of air will only hold a certain ammount of water before it becomes saturated and can't absorb any more. That ammount of absorbtion will vary according to the temperature of the air. So if the air touches a colder surface, the temperature where it touches will reduce and the moisture will condense, hence water always condensing on cold windows and hull sides that are in contact with the outer air or cold water.

If you insulate parts of the boat, then you will get more condensation on areas that aren't insulated. typically inside cupboards and lockers, under berths etc. Just putting in sheets of insulation doesn't neccessarily remove the problem, as it needs to be bonded to the surfaces you are insulating to remove any air gap. If you don't, then moisture will condense on the surfaces behind the insulation and run down to gather at the lowest point. The problem then becomes that you can't see where it is coming from. This is why liveaboard canal boats are always spray foam insulated over the entire inside of the shell before fitout.

One of the biggest heat loss areas and therefore high condensation areas are the windows, so the smaller the windows the less cold surface. If you can double glaze the windows in some way in boats with large windows particularly, then you will cut down condensation and heat loss considerably. On most seagoing boats it's not easy to do, but if there is a raised frame around the window, you can use cheap double glazing film which is very effective. Otherwise insulated window covers in polystyrene or similar give protection.

Ventilation is essential, so allow air to circulate through the boat and through closed off areas. Fresh outside air is likely to be less saturated as it starts off colder. If you are on a mains hookup then it might be worth considering a dehumidifier, but they can be power eaters.

Finally, produce as little moisture inside the boat as possible, stopping breathing helps but as that is not possible other methods are neccessary. Boil only the water you need rather than excess ammounts, have a strip wash rather than a shower, maybe put a small extractor fan in a vent, a low consumption 12v computer cooling fan is ideal for removing steam in heads and galley vents. Try to dry towels etc outside the boat.

Hope some of that helps,

Roger

 

[floebs]

Finally, produce as little moisture inside the boat as possible, stopping breathing helps but as that is not possible other methods are neccessary.

Thanks Roger, I tried this but could only last for 45 seconds!!!

On the ventilation subject, does anyone have any suggestions about what type of ventilation - other than simply opening a hatch/window - does anyone have any experience with installing permanent ventilation systems onboard, preferably ones that work without direct power.

In Australia our house had a whirlygig on the roof - a wind driven ventilator system - does such a thing exist for a boat?

Again, thanks in advance - all these suggestions are very helpful in how to tackle/reduce condensation and make living onboard far more comfortable!

EDIT: Found this which looks like an interesting option ... anybody had any experience with these, or similar?

 

[floebs]

I had well insulated walls but streaming condensation sometimes. I fitted permanent ventilation and the problem vanished.

Also, the areas that seemed permanently wet all dried out in less than a week and have stayed dry.

Mike, what type of permanent ventilation did you end up fitting?