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Re-insulating liveaboard bit by bit


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I would be inclined to re-use the existing insulation with the correct adhesive in the areas it is best suited to (curves), perhaps as others have said, doubling it up, and do the rest with Kingspan/Celotex (flat).

 

There are many brands of foil faced expanded foam insulation. I have not noticed any difference between them. The main thing is thickness - as thick as you can go but note that anywhere you increase the thickness you will also need thicker battens, either by fixing over the top of the existing or removing and putting in a single thickness piece. Also worth being aware that, if you have access to suitable transport, there are places which sell the seconds of insulation boards. Since you are going to be cutting it about rather than using full boards this can make a significant saving as you can cut out the damage.

 

I would be inclined to re-use the ply as others have said, after sealing the backs, but to cut boards at the bulkheads to make it easier for future works. This is likely to mean that you need to supplement it, which won't match, so I would pick an area to re-finish with new boards and trim, and do that area last. You can then start with the first zone, remove the insulation, sort out the steel behind, re-fit the old insulation and the new insulation in that area, and then board over. Take any extra boards necessary from the next zone to finish the first one, and then carry on in that fashion, robbing boards and insulation ahead of yourself as necessary.

 

If you get materials together now as they come up cheap on Ebay/Gumtree/Freecycle - particularly thinking of adhesives, fixings such as screws and cups if you want to go that way rather than filling over, trim mouldings, varnish/paint (and the insulation and extra battens if you can find somewhere to store them) then you should be able to hit the ground running at Easter and get the job done before it gets cold again.

 

Alec

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There are several threads on this topic.  My method (I've done four fit-outs like this) is to use slab insulation and a polythene vapour barrier.

 

https://www.canalworld.net/forums/index.php?/topic/63615-insulating-a-boat-to-prevent-condensation/&do=findComment&comment=1225136

 

There is nothing wrong with Thinsulate, by the way.  I've got it in the back cabin of my butty where space is at a premium.  Done properly, it's higly effective.  

 

Edited by koukouvagia
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22 minutes ago, agg221 said:

I would be inclined to re-use the existing insulation with the correct adhesive in the areas it is best suited to (curves), perhaps as others have said, doubling it up, and do the rest with Kingspan/Celotex (flat).

 

There are many brands of foil faced expanded foam insulation. I have not noticed any difference between them. The main thing is thickness - as thick as you can go but note that anywhere you increase the thickness you will also need thicker battens, either by fixing over the top of the existing or removing and putting in a single thickness piece. Also worth being aware that, if you have access to suitable transport, there are places which sell the seconds of insulation boards. Since you are going to be cutting it about rather than using full boards this can make a significant saving as you can cut out the damage.

 

I would be inclined to re-use the ply as others have said, after sealing the backs, but to cut boards at the bulkheads to make it easier for future works. This is likely to mean that you need to supplement it, which won't match, so I would pick an area to re-finish with new boards and trim, and do that area last. You can then start with the first zone, remove the insulation, sort out the steel behind, re-fit the old insulation and the new insulation in that area, and then board over. Take any extra boards necessary from the next zone to finish the first one, and then carry on in that fashion, robbing boards and insulation ahead of yourself as necessary.

 

If you get materials together now as they come up cheap on Ebay/Gumtree/Freecycle - particularly thinking of adhesives, fixings such as screws and cups if you want to go that way rather than filling over, trim mouldings, varnish/paint (and the insulation and extra battens if you can find somewhere to store them) then you should be able to hit the ground running at Easter and get the job done before it gets cold again.

 

Alec

Great minds think alike... or something... that process is exactly how I see it going - 2 boards off fix the first, remove the third, fix the second and onwards. Damn shame the boards are so big, if they were 4ft the job would be so much more containable! Really - zero storage, I'm 200 miles away from anyone I know from my past that lives in a house... and I have no transport so not worth renting storage - can't drive to a medical condition or I'd buy a temporary van which I could fetch and store materials in.

 

Probably my best option, if I were a barsteward, would be clean up and paint over the mould, sell it and buy a good one. It's worth considering. :(

 

Or.. buy a small one to live in while we work and sell it on after, the prices are only going up...

Edited by Slow and Steady
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A full polythene vapour barrier behind the timber lining is a good idea   IF   you can fix through it without leaving holes otherwise it might as well not be there.

Nothing sticks to polythene.

The foil and tape on Kingspan is an effective barrier if installed properly.

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2 minutes ago, Tracy D'arth said:

A full polythene vapour barrier behind the timber lining is a good idea   IF   you can fix through it without leaving holes otherwise it might as well not be there.

Nothing sticks to polythene.

The foil and tape on Kingspan is an effective barrier if installed properly.

I think this is where spray foam wins? It's not suitable for us, but does cover the steel and get in every nook and cranny. As said earlier I have insulated a large wooden building in this way, taping all the joints to form a vapour barrier then panelling it out but a steel box is another thing altogether isn't it? But I know it can be done and I have the determination and experience to at least know to not cut corners.

29 minutes ago, agg221 said:

I would be inclined to re-use the existing insulation with the correct adhesive

Maybe... but I have a sort of thing about it now! Perhaps when I start to dismantle I'll change my mind. Also if it's kind of half-baked glued on I'm likely to destroy it removing it - all that work I think I'd be more content to do it completely differently.

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6 minutes ago, Slow and Steady said:

I think this is where spray foam wins? It's not suitable for us, but does cover the steel and get in every nook and cranny. As said earlier I have insulated a large wooden building in this way, taping all the joints to form a vapour barrier then panelling it out but a steel box is another thing altogether isn't it? But I know it can be done and I have the determination and experience to at least know to not cut corners.

Maybe... but I have a sort of thing about it now! Perhaps when I start to dismantle I'll change my mind. Also if it's kind of half-baked glued on I'm likely to destroy it removing it - all that work I think I'd be more content to do it completely differently.

I am not a fan of sprayed foam.

 

If the Thinsulate  fills the space between steel and lining I would think it is fine, It can't fall out then, no glue required, It was expensive and efficient when it was made. It will have a recoverable value to someone else. Why buy new when you can use the old? just install it properly.

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45 minutes ago, Tracy D'arth said:

I am not a fan of sprayed foam.

 

If the Thinsulate  fills the space between steel and lining I would think it is fine, It can't fall out then, no glue required, It was expensive and efficient when it was made. It will have a recoverable value to someone else. Why buy new when you can use the old? just install it properly.

Well, nothing is decided and I am listening. I'll see what's what when I start to dismantle the panels and if the cause of my problems seems to be something else or bad fitting then I may indeed reuse it, I'm not keen on spending money unnecessarily but really - I do not think it a recoverable product if it's glued in place? At this point I'm considering my options and getting advice and opinions including yours which I'm grateful for. I restored and mechaniced old vehicles for a living for a while and if there was one thing I learned it was not to pre-order parts on guesswork - I really will not make a decision without having a damn good look first and that will include trying to remove some if it needs removing and seeing if it can be reinstalled - this is something I would not have tried without this discussion and enlightenment about the thinsulate currently fitted.

Thanks again for your advice.

Edited by Slow and Steady
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6 hours ago, TheBiscuits said:

Kingspan or similar.  It's spray foam with reflective foil both sides.

 

Stick to cabin sides, fill every single tiny gap with expanding foam from a can and tape joints correctly with aluminium tape.  Get a proper foam gun, don't use the plastic straw cans.

 

It can be done a bit at a time, if you are doing it DIY you can make sure it's all done correctly and you can buy it in small quantities to smooth your budget if necessary.

 

Long term insulation values are actually better than the same thickness of spray foam because of the foil layer.

 

Yes I agree with this. I'd use 1" thick  cellotex or kingspan above the gunwales and 2" thick below if possible. Stick it to the steel with cans of spray foam or tubes or Stixall (Toolstation) Have a go on the first couple and decide which "adhesive" you prefer. 

 

Small gaps behind the boards don't matter that much as they contain a finite amount of air and water vapour. Gaps between the boards are much more critical and you must fill all gaps.

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8 minutes ago, blackrose said:

 

 

 

Small gaps behind the boards don't matter that much as they contain a finite amount of air and water vapour. Gaps between the boards are much more critical and you must fill all gaps.

Correct, trapped air is an insulator.  You create a still air space, which is exactly what insulation like rockwool, glass fibre, foam rubber and Thinsulate do, that's how they work.

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7 hours ago, TheBiscuits said:

For tighter curved bits, slice the back foil in straight lines so the sheet can bend easily.  Try not to snap it!  It's best if you can fill the v shaped gaps with expanding glue a few seconds before fitting it.  Fit it dry first then remove, glue and install.

 

6 hours ago, BEngo said:

Try to avoid cutting the kingspan to make it easy to bend as you create a lot of less well insulated spots. There will show, sooner or later.

 

Rather than cut through the foil on the back face of the sheet, I would use a circular saw to cut a series of parallel grooves to a depth of 1/2 to 2/3 of the sheet thickness in the front face of the sheet. The sheet should then bend easily, and the grooves will close up. Once glued into place any remaing grooves could be filled with spraycan foam (although I probably wouldn't bother), and then cover the grooves with foil tape. 

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14 hours ago, Slow and Steady said:

Great minds think alike... or something... that process is exactly how I see it going - 2 boards off fix the first, remove the third, fix the second and onwards. Damn shame the boards are so big, if they were 4ft the job would be so much more containable! Really - zero storage, I'm 200 miles away from anyone I know from my past that lives in a house... and I have no transport so not worth renting storage - can't drive to a medical condition or I'd buy a temporary van which I could fetch and store materials in.

 

Probably my best option, if I were a barsteward, would be clean up and paint over the mould, sell it and buy a good one. It's worth considering. :(

 

Or.. buy a small one to live in while we work and sell it on after, the prices are only going up...

Depending on the area you are based in there may be a boatyard or marina that is geared up for repairs and fit outs by owners,  Debdale on the Leicester arm which have hardstanding and possibly storage is one example but there are others.

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15 hours ago, Tracy D'arth said:

Correct, trapped air is an insulator.  You create a still air space, which is exactly what insulation like rockwool, glass fibre, foam rubber and Thinsulate do, that's how they work.

 

Yes, except that insulation works by creating cells or very small spaces of air in which thermal convection cannot occur and thermal conduction (and radiation) are reduced by the insulation material itself. That is not necessarily the case with a larger air gaps. However in this case as any small gap would be behind the insulation it shouldn't reduce the overall effectiveness of the material. 

 

I had a friend who bought a steel sailing boat to live on which had no insulation at all behind the wooden lining - just a big 2" gap. He bought the boat in summer and when I asked what he was going to do about it he said "it has air insulation". Once winter came he realised his error. Although air may have good insulation properties which are utilised in insulation materials, a larger air gap (even trapped air) doesn't because thermal convection, conduction and to a lesser extent radiation can occur within the gap. 

Edited by blackrose
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11 hours ago, David Mack said:

 

 

Rather than cut through the foil on the back face of the sheet, I would use a circular saw to cut a series of parallel grooves to a depth of 1/2 to 2/3 of the sheet thickness in the front face of the sheet. The sheet should then bend easily, and the grooves will close up. Once glued into place any remaing grooves could be filled with spraycan foam (although I probably wouldn't bother), and then cover the grooves with foil tape. 

 

That's probably a better method than the one I described.  Harder to cut but easier to seal.

 

As noted by several others upthread, for gentle curves it doesn't need to be cut it just needs holding in place until the glue dries.

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1 hour ago, TheBiscuits said:

 

That's probably a better method than the one I described.  Harder to cut but easier to seal.

 

As noted by several others upthread, for gentle curves it doesn't need to be cut it just needs holding in place until the glue dries.

 

Never tried it myself but a couple of acrow-props might be useful. Otherwise just lengths of timber wedged into place.

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4 hours ago, blackrose said:

 

Yes, except that insulation works by creating cells or very small spaces of air in which thermal convection cannot occur and thermal conduction (and radiation) are reduced by the insulation material itself. That is not necessarily the case with a larger air gaps. However in this case as any small gap would be behind the insulation it shouldn't reduce the overall effectiveness of the material. 

 

I had a friend who bought a steel sailing boat to live on which had no insulation at all behind the wooden lining - just a big 2" gap. He bought the boat in summer and when I asked what he was going to do about it he said "it has air insulation". Once winter came he realised his error. Although air may have good insulation properties which are utilised in insulation materials, a larger air gap (even trapped air) doesn't because thermal convection, conduction and to a lesser extent radiation can occur within the gap. 

Mulling it over, perhaps I can do as Linnet's photo earlier, then re-use my thinsulate to fill the resultant recessed panels. Thinsulate maybe an ok product but I fail to see how it can be used alone AND create a vapour barrier plus it's only ever advertised as an acoustic insulator - 3M do not provide any thermal spec for it. It's supposed to expand to 42mm thick, but where I can see mine as per my photo, it definitely has not expanded to anywhere near that claim, more like 15mm or 20mm if I was being kind.  Considering the upheaval and PITA this job will be, what I'm thinking right now is that rebuilding it as it is/was would be a massive waste of effort.

 

 

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On 05/01/2022 at 15:08, frangar said:

Thats 3M Thinsulate.....which if applied correctly is actually a very good insulator for both heat and sound and wasn't a cheap option. It was marketed for boats a few years ago and in some ways is easier to apply than kingspan as it copes well with curves and framing etc. We used it on a couple of new builds and it was excellent for retro work. It should be glued to the steel using the correct 3M adhesive...note the steel needs to be dry for for the glue to work so this time of year isnt great. To my mind a good thinsualte job is far better than a mediocre spray foam but on new builds spray foam is now probably cheaper.

 

https://www.marineindustrial.co.uk/Catalogue/Thermal-Acoustic-Insulation/3M/Thinsulate

 

http://www.sikaflex.co.uk/thinsulate

 

edited to add links

 

I was about to say the same. Definitely 3M Thinsulate.

 

I have it on my 14 year old boat, which is dry and warm. It seems like it has been badly stuck on the OP's boat, possibly with the wrong adhesive.

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16 minutes ago, cuthound said:

 

I was about to say the same. Definitely 3M Thinsulate.

 

I have it on my 14 year old boat, which is dry and warm. It seems like it has been badly stuck on the OP's boat, possibly with the wrong adhesive.

Some of the issue might be that the correct adhesive looks very much like a thin PVA type glue....but I dont think it is given the price and how it sticks to steel...however if a normal PVA or contact adhesive was used then that could be the problem.

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I suspect the problem may have many aspects for example the gluing, the fact it hasn't expanded as the makers claim, air getting in behind the panels as the panel fixing glue has deteriorated and quite possibly less than complete coverage. 

Whatever, it does need an overhaul and despite others having success with it my own view is not favourable. I appreciate that any insulation system succeeds or fails on the quality of it's installation and a narrowboat being a steel box makes the symptoms of failure severe. This boat has quite a few defects that would have taken a few more hours to do properly but will take days or weeks to correct. Another is the hull builder built the correct sq m of skin tanks but the engine installer connected only one of the two, then the interior fitter built permanently over it's air bleed - not even an access hatch to it. Connecting the second tank requires bigger connections than installed and due to the engine being in the way, access to the lower one is impossible without removing the engine first. That is... annoying - it's a Beta 43 so quite a chunk of a thing. Meanwhile I cannot venture onto a river. All for the sake of a few hours extra work when the boat was built. I think I may be able to gain enough access by lifting one end of the engine with a block and tackle, but I'll be surely cursing the lazy arze builder throughout. If I was 30 instead of being in my 60's I'd probably just get on with it but these things are not as much un as they used to be. :rolleyes:

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On 05/01/2022 at 13:37, Slow and Steady said:

Hi everyone, first post so go easy on me! 

 

Background:

 

For my sins I have a 60ft narrowboat that I live on with my grown up son. We kind of look after each other.

We bought the boat in a hurry 4 years ago, I had a smaller REALLY NICE one but we had to expand when my son suddenly had to join me.

So... we chose this one because of it's layout - he lives at one end in a sort of bachelor pad that was a 15ft bedroom, I live at the other end with a living room c/w solid fuel stove, galley and walkthrough bathroom between. The front has a sort of bay window instead of a cratch, the rear has an engine room and small steering deck. I'd call it a trad... but it's not really, it's a flat on water, I don't think it was ever really intended to be much of a boat, it's not boaty if you know what I mean.

 

It was obviously "designed" to have a large open interior and so the panelling is not deep and the insulation is terrible - not in terms of heat (though that isn't very good) as much as condensation. It's been insulated with fluffy stuff off a roll, black one side, white on the other about an inch thick. I don't know exactly what it is but here's a photo so you get the idea, fag papers for scale. 

 

1826200251_IMG_20171208_102159106small.jpg.4be9b1b9fc9875bec9b692c351b00472.jpg

 

That's it - that is all we have for insulation! It was glued-ish to the steel but... like everything else in this naughty boat it's coming adrift.

 

The whole fitout has been constructed with no more nails and pins to hold it in place while it set. Bulkheads fixed in place with those plastic blocks used in kitchen cabinets. 15 years later it's falling to pieces. A real shame as it's good quality oak faced ply and oak trim. Because it's falling to pieces, air is able to circulate behind the panels, condensation forms against the steel, it's BAD, it's dripping, it's going mouldy in a big way, the boat smells of rotting wood.

 

There really is only one thing for it - start again. Now, what I'd really like to do is strip the entire interior, spray foam it and rebuild. There are a number of things that make this impractical - we live on it, we have nowhere to store things, we have no transport, we're quite poor and need to get max value from spending.

 

With the above in mind it seems like our only approach would be to start at one end and do the job in chunks. It's not going to be straightforward room by room either as the bulkheads are all partway along the lining ply sheets, it's wired and plumbed and we don't want to rewire etc etc. The one thing we do have is time, lots of time.

 

That's where we are, the boat is not sellable like it is, the layout is perfect for us, it has a beta engine that's barely past it's first oil change hours!, it has good elec fitout with travel power, webasto central heating etc etc, so it's not all doom and gloom. The steelwork and welding is top notch in good order, 2 pac "blacking". It would be a great home/boat if not for the poor insulation situation.

 

Here's the question - if you were in this position, what insulation would you install? It seems to me essential that no air is permitted to get at the steel in order to stop that condensation, we'd be happy if the space inside got smaller in  the process and whatever we do must be a permanent solutio with much better thermal properties than the skinny stuff above. Cost of materials? Well it matters, but with the effort involved it's secondary to the result - if it'll help it will be purchased. I'm handy with DIY, I have lots and lots of tools. In fact, tools are about all I do own apart from clothes!

 

Thanks for reading this long first post. I'm a long time lurker here so I thought I'd just wade in. No - we're not planning on bridge hopping, moving to London, CCing in one sq mile etc etc. We have always had marina mooring but we need to get this boat sorted while we're here and then we'll be off on a real open ended cruise to see where it takes us.

Your current insulation looks like thinsulite? I have it in 2 thirds of the boat, mine is glued to the hull and to the wood panels so it has 2 layers and is very warm. The final third is sprayfoam which is equally as good and tends to do better with condensation 

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8 hours ago, Slow and Steady said:

Mulling it over, perhaps I can do as Linnet's photo earlier, then re-use my thinsulate to fill the resultant recessed panels. Thinsulate maybe an ok product but I fail to see how it can be used alone AND create a vapour barrier plus it's only ever advertised as an acoustic insulator - 3M do not provide any thermal spec for it. It's supposed to expand to 42mm thick, but where I can see mine as per my photo, it definitely has not expanded to anywhere near that claim, more like 15mm or 20mm if I was being kind.  Considering the upheaval and PITA this job will be, what I'm thinking right now is that rebuilding it as it is/was would be a massive waste of effort.

 

 

 

Yes, if you're going to all the trouble of ripping the wooden lining off then do the job properly with some decent insulation, not the same stuff that's failed previously.

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