Re-insulating liveaboard bit by bit

[Slow and Steady]

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. 

 

 

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.

Edited January 5, 2022 by Slow and Steady

[TheBiscuits]

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.

[Tracy D'arth]

Mr Biscuits is on the ball. Kingspan-Cellotex is available in differing thicknesses.  Stick to steel with 5 minute expanding polyurethane wood glue from Screwfix. Wedge panels in as tight as you can between the stringers and stiffeners.  Any rusty steel just knock off the scale and give it one coat of Vactan, don't bother wire brushing to bright steel, the Vactan will convert any surface rust better.

The roof is the hardest part but the most important for condensation, 25mm Kingspan will bend to fit if you prop it whilst the glue cures, use 2 sheets if need be on top of one another. That's the advantage of 5 minute glue.

Use the stickiest aluminium foil tape you can find on ebay from China, cheap, over all joints after foaming any and all gaps with can foam, fill every space completely.

Varnish the backs of all lining boards with good high VOC varnish or even gloss paint to seal them, do not use anything that you can wash brushes out with water and detergent, its rubbish and water based, not oil based.

The rotting wood smell could well be from under the floor. Ensure it is dry down there whilst you are at it and that you have not got dry rot fungus in any timber. It will be wetter at the stern if anywhere. But could have rot anywhere.

As you are obviously on mains electricity, consider buying a compressor dehumidifier and running it all day every day to dry  the whole boat out.

DE Longie make a  good one, suitcase size, that is not too expensive. There will be loads second hand in spring. The crystals in a  box things are a waste of money.

You will be amazed at how much water it will extract from the boat woodwork.

Edited January 5, 2022 by Tracy D'arth

[TheBiscuits]

10 minutes ago, Tracy D'arth said:

consider buying a compressor dehumidifier

 

That's the only bit of your post I disagree with.

 

The desiccant wheel type are many times better than the compressor type.  They extract more moisture for less electricity.

 

Look at the Meaco range, but I think Lidl occasionally have some of that type in as a special.

 

 

[Slow and Steady]

I do have a dehumidifier...it can't keep up.

The rot and white mould is visually apparent eve on ceiling panels. I know it's condensation as it runs inside of the wall panels until it hits horizontal battens (or whatever the panels are fixed to) then soaks out through the ply. The back of the ply will be untreated, this was a slap together and run job, though the craftsmanship of the woodwork is excellent in itself so clearly done by someone skilled.. but in a hell f a hurry. Whatever they used on the interior side of the panels and woodwork I think was one coat and sprayed after all the chippy work was complete. The modern world eh?

 

Ref kingspan, not very Flexible is it? Really - not at all flexible, I have used it before in a summerhouse/office I built. My worry would be that on the ceiling it would slowly straighten itself out and delaminate leaving the silver backing stuck to the ceiling? Any thoughts?

I would take a photo of the worst mouldy bit and post if I could get past my embarrassment of how BAD it is! Maybe later.

[Slow and Steady]

Got to admit also that without a handy cratch door the air flow in here is poor. Getting air in at low level is nigh on impossible. To that end I have built in a ducted inlet opposite the stove that does (probably) help a little, but with the really poor thermal insulation it's all too tempting to keep the windows shut. We do have mushroom vents but to illustrate the ventilation situation, cold air often blasts IN from them when I know it should be going out - one is directly over my head in bed and I often block it up because of this. It's a perfect storm isn't it. I feel like one of those poor people who can't afford heating, keeps all the windows shut and wonders why their home is going mouldy. In my case I can afford the heating but it's just not enough due to the poor insulation.

 

My previous boat was self fitted out by someone who did a fantastic job, it was warm and toasty and DRY - I know it can be done.

Edited January 5, 2022 by Slow and Steady

[TheBiscuits]

2 minutes ago, Slow and Steady said:

Ref kingspan, not very Flexible is it? Really - not at all flexible, I have used it before in a summerhouse/office I built. My worry would be that on the ceiling it would slowly straighten itself out and delaminate leaving the silver backing stuck to the ceiling? Any thoughts?

 

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.

 

8 minutes ago, Slow and Steady said:

I would take a photo of the worst mouldy bit and post if I could get past my embarrassment of how BAD it is!

 

If your condensation is that bad, you haven't got enough ventilation.  Turn the fire up high and open some doors and windows.  Don't leave a kettle on the stove all the time.

 

Are you 100% sure you don't have a leaking roof?

[frangar]

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

Edited January 5, 2022 by frangar

[Tracy D'arth]

11 minutes ago, Slow and Steady said:

I do have a dehumidifier...it can't keep up.

The rot and white mould is visually apparent eve on ceiling panels. I know it's condensation as it runs inside of the wall panels until it hits horizontal battens (or whatever the panels are fixed to) then soaks out through the ply. The back of the ply will be untreated, this was a slap together and run job, though the craftsmanship of the woodwork is excellent in itself so clearly done by someone skilled.. but in a hell f a hurry. Whatever they used on the interior side of the panels and woodwork I think was one coat and sprayed after all the chippy work was complete. The modern world eh?

 

Ref kingspan, not very Flexible is it? Really - not at all flexible, I have used it before in a summerhouse/office I built. My worry would be that on the ceiling it would slowly straighten itself out and delaminate leaving the silver backing stuck to the ceiling? Any thoughts?

I would take a photo of the worst mouldy bit and post if I could get past my embarrassment of how BAD it is! Maybe later.

25mm Kingspan will happily shape to the roof unless you have an unusually curved or angled one. A prop on a sheet of thin ply to  spread the load will bend it to the roof whilst the glue cures. Polyurethane glue will not let go, and the backing foil will not delaminate.  Its like cack on an army blanket.

I have never tried a desiccant wheel type but I know the box ones are useless.

[TheBiscuits]

 

3 minutes ago, Slow and Steady said:

We do have mushroom vents but to illustrate the ventilation situation, cold air often blasts IN from them when I know it should be going out - one is directly over my head in bed and I often block it up because of this.

 

You need lots more low level ventilation then from somewhere.  If your cooking / washing / breathing moisture can't leave through the mushroom vents it's all staying in the boat.  Lots of rot will cause you breathing problems so fix it, soon, for the sake of your health.

 

On the plus side, drier air feels a lot warmer than damp air at the same temperature.  Get a hydrometer so you can see what relative humidity you have in your boat, and try and keep it 50 - 60%.  

 

On a dry windy day, open the entire boat up - doors, windows, hatches and let it blow through.

 

You do need to check there isn't a few inches of standing stagnant water in your cabin bilge as @Tracy D'arth suggested earlier.

[Slow and Steady]

2 minutes 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.

 

 

If your condensation is that bad, you haven't got enough ventilation.  Turn the fire up high and open some doors and windows.  Don't leave a kettle on the stove all the time.

 

Are you 100% sure you don't have a leaking roof?

Thanks for the tip, I think you're right and it's the foil that stops it bending.

Yes you're correct about the ventilation, I posted about that as you were typing - just above your post. This is something I will tackle along with the refit as I will be able to build in some low level ducting as I go. In at the bottom, out at the top.

Yes I'm sure about the roof, I painted it myself with all the fittings off and sealed them and every screw when I refitted. It's amazing how much water can get in through the tiniest crack - I had a nav light off the side and one screw hole let it LOADS until I stopped it.

[linnit]

Edited January 5, 2022 by linnit
To add comment...Kingspan for me

[Slow and Steady]

2 minutes ago, TheBiscuits said:

 

 

You need lots more low level ventilation then from somewhere.  If your cooking / washing / breathing moisture can't leave through the mushroom vents it's all staying in the boat.  Lots of rot will cause you breathing problems so fix it, soon, for the sake of your health.

 

On the plus side, drier air feels a lot warmer than damp air at the same temperature.  Get a hydrometer so you can see what relative humidity you have in your boat, and try and keep it 50 - 60%.  

 

On a dry windy day, open the entire boat up - doors, windows, hatches and let it blow through.

 

You do need to check there isn't a few inches of standing stagnant water in your cabin bilge as @Tracy D'arth suggested earlier.

Thanks again, I've checked under the floor, it's just about the only place this boat is dry!!!

For sure the low level ventilation is a big part of the problem. I do recognise this and it's part of the plan. I won't be doing any work until the spring so for the rest of this winter will just have to cope as best we can and be ready to hit the ground running so to speak when the weather warms up a bit. As noted, with the damp at this time of year nothing is going to stick well...  apart from spray foam.

4 minutes ago, linnit said:

That looks like mine will in my dreams.

I see there must be air gaps under the wood lining? Is this considered "ok"? I guess it should be fine as long as air cannot circulated through them?

Over the battens, is that just thin ali tape or is it insulating type stuff?

Thanks for posting the photo.

[BEngo]

When gluing kingspan to the roof, make up a couple of curved battens with a radius on top that is the same as the roof less the thickness of the kingspan.  Use these with props from the floor to form and hold the kingspan to shape while the glue sets. The foam will not go anywhere after that.

 

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.

 

When re doing the floor fit plenty of inspection hatches, so you can get at the ballast and see WIHIH  underneath. There also needs to be one at the very back of the cabin for pumping out any water that gets in.  It is also worth considering fitting a fan to cool the fridge condenser, drawing its air from under the floor.

 

 

N

Edited January 5, 2022 by BEngo
Add fridge fan.

[Slow and Steady]

Damn. this is going to be a PITA, I'm going to have to buy the Kingspan/3M or whatever a bit at a time due to lack of storage so no bulk deals either. Oh well!

 

I'm intending to re-use the ply paneling if I can and paint it if I ruin it's good looks, which I no doubt will. One good thing is that it must be "proper stuff" and it's not delaminating or warping despite the conditions. My god, the price of oak faced marine ply with a decent thick veneer is ... high... and there are acres of it.

5 minutes ago, BEngo said:

When gluing kingspan to the roof, make up a couple of curved battens with a radius on top that is the same as the roof less the thickness of the kingspan.  Use these with props from the floor to form and hold the kingspan to shape while the glue sets. The foam will not go anywhere after that.

 

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.

 

When re doing the floor fit plenty of inspection hatches, so you can get at the ballast and see WIHIH  underneath. There also needs to be one at the very back of the cabin for pumping out any water that gets in.  It is also worth considering fitting a fan to cool the fridge condenser, drawing its air from under the floor.

 

 

N

I'm not intending to do anything with the floor but I have had some of it up previously - looking good and bone dry under there. I have an inspection hatch at the back and from the pieces I've had up there is nothing to stop any water making it's way back there. The floor supports have gaps at the ends - at least that's one thing done correctly.

 

 

Hi all - thank you all so much for your replies and advice, I feel like a plan coming together and it's so nice to get this off my chest so to speak.

[linnit]

12 minutes ago, Slow and Steady said:

Over the battens, is that just thin ali tape or is it insulating type stuff?

Thanks for posting the photo.

I used a cheap bandsaw to slice thin strips and taped over with foil tape..I used 40mm  Kingspan/celotex and cut into pieces again with bandsaw to create an airtight gapless fitting on roof..in 8 yrs i have never had a drip of condensation

[Slow and Steady]

Right - so does the team think 1" will be enough? That would REALLY help with the window and porthole surrounds and general refit of all the woodwork, but if more would be better...

[Slow and Steady]

2 minutes ago, linnit said:

I used a cheap bandsaw to slice thin strips and taped over with foil tape..I used 40mm  Kingspan/celotex and cut into pieces again with bandsaw to create an airtight gapless fitting on roof..in 8 yrs i have never had a drip of condensation

Brilliant, real life advice - do you inhabit your boat through the winter? I think this makes all the difference, for 9 months of the year we have no problem at all, then... bosh - dripping. I suspect if we weren't here and left a couple of windows open it would stay dry.

[Slow and Steady]

33 minutes ago, 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.

Interesting. Thanks for identifying it. Hope it wasn't you guys who did my boat! I have to say my boat is constructed with very good materials and spec all round, from the electrics to the engine to the hull and the fitout. The problems stem from the cheaping out on the labour fitting it out. It's interesting to read that you have a positive view of the insulation. That being said, why would you think I have the problems that I do? I know you can only guess but an educated guess is better than I can do. I'm quite looking forward to removing some of the lining and finding out exactly what's been going on but until then...

[frangar]

2 minutes ago, Slow and Steady said:

Interesting. Thanks for identifying it. Hope it wasn't you guys who did my boat! I have to say my boat is constructed with very good materials and spec all round, from the electrics to the engine to the hull and the fitout. The problems stem from the cheaping out on the labour fitting it out. It's interesting to read that you have a positive view of the insulation. That being said, why would you think I have the problems that I do? I know you can only guess but an educated guess is better than I can do. I'm quite looking forward to removing some of the lining and finding out exactly what's been going on but until then...

There was a few fitters both pro and self fit out using it....I  think we used it for one new full fit out at the customers request and one refit on a back cabin. I would suggest that possibly the correct adhesive wasn't used or the steel was damp if it failed. As I recall even the adhesive wasn't cheap. Ive used it under the counter in my own boat and its been there over 10 years now and still holding ok with no other support eg wood lining etc including on the underside of the deck.

[Slow and Steady]

19 minutes ago, frangar said:

There was a few fitters both pro and self fit out using it....I  think we used it for one new full fit out at the customers request and one refit on a back cabin. I would suggest that possibly the correct adhesive wasn't used or the steel was damp if it failed. As I recall even the adhesive wasn't cheap. Ive used it under the counter in my own boat and its been there over 10 years now and still holding ok with no other support eg wood lining etc including on the underside of the deck.

Sigh, it's such a shame when a boat is built with good intentions but somewhere along the line goes over budget and the only savings possibilities are from doing it faster. I know a couple were built at the same time using different hull builders and my hull built by a steel constructor who though extremely good had never built a narrowboat and I know the builder and steelwork firm fell out big-time over it. I think that's where it went awry and over budget. The boat was built to make a profit for a marina owner who was by all accounts not a nice person. It's not hard to imagine that he would have put pressure on the fitout people to come up with a cheap price or imagine that he bought the materials for both boats himself, in bulk prior. I've done a lot of digging into the boat history including going to see the hull builder but i can't find out who did the fitout - it would be interesting to talk to them.

 

Taking on board that the thinsulate, despite being marketed as a sound insulation, is ok stuff, I'm thinking the main problem I have started when the the no more nails type glue started to disintegrate allowing air to get in behind the panels. Hmm. Well, at least I know something NOT to do when I finally get to putting it back together.. I wonder how the battens are fixed to the hull? Anyone know how this is normally done? I've always wondered.

Edited January 5, 2022 by Slow and Steady

[Tracy D'arth]

I would reuse the Thinsulate maybe doubled up, for the more awkward bits. If it was not stuck perhaps it moved and left gaps. Is it taped together over the joins and frames?

It is good stuff if applied properly.

Don't think that spray foam is the bee's knees, I have seen loads too thinly applied and plenty come unstuck from the steel too. It  emits formaldehyde gas for months as it cures, not nice. 

[frangar]

3 minutes ago, Tracy D'arth said:

I would reuse the Thinsulate maybe doubled up, for the more awkward bits. If it was not stuck perhaps it moved and left gaps. Is it taped together over the joins and frames?

It is good stuff if applied properly.

Don't think that spray foam is the bee's knees, I have seen loads too thinly applied and plenty come unstuck from the steel too. It  emits formaldehyde gas for months as it cures, not nice. 

Plus if any welding is needed it destroys the spray foam leaving cold spots 

[BWM]

Thinsulate is excellent stuff, we used one that is only around 5mm thick with membrane and foil and it is up to the job, with no condensation and good insulation summer and winter. 

 I'd definitely re use the ply as it hasn't got any better over the years.

 It might be worth asking around if anyone had a boat you could let during the summer whilst doing the work as the steelwork would dry out much better if it was stripped and exposed in one go - and the job would be much more straightforward and quick against working around people and contents!

[Tracy D'arth]

19 minutes ago, Slow and Steady said:

Sigh, it's such a shame when a boat is built with good intentions but somewhere along the line goes over budget and the only savings possibilities are from doing it faster. I know a couple were built at the same time using different hull builders and my hull built by a steel constructor who though extremely good had never built a narrowboat and I know the builder and steelwork firm fell out big-time over it. I think that's where it went awry and over budget. The boat was built to make a profit for a marina owner who was by all accounts not a nice person. It's not hard to imagine that he would have put pressure on the fitout people to come up with a cheap price or imagine that he bought the materials for both boats himself, in bulk prior. I've done a lot of digging into the boat history including going to see the hull builder but i can't find out who did the fitout - it would be interesting to talk to them.

 

Taking on board that the thinsulate, despite being marketed as a sound insulation, is ok stuff, I'm thinking the main problem I have started when the the no more nails type glue started to disintegrate allowing air to get in behind the panels. Hmm. Well, at least I know something NOT to do when I finally get to putting it back together.. I wonder how the battens are fixed to the hull? Anyone know how this is normally done? I've always wondered.

No More Nails or  Gripfill was often used for batten fixing but it lets go eventually. I usually wedge and glue battens with either OB1 or Geocel The Works but the aforementioned 5 Minuit Wood Polyurethane sticks brilliantly and is fast curing saving standing there holding bits up.  It foams slightly as it cures so it fills gaps and irregularities. Works best if you lightly dampen the wood first.

I have seen a fitter fix all the battens with self drilling screws from the inside right through the steel sides above the water line. The boat looked like a porcupine before he went round outside with a hammer and snapped them all off.  It must of looked awful a few years after the painting was done.