Retrofitting Insulation

[Doodlebug]

Hi all,

 

Our boat really wasn't build for live aboards, the insulation is less than an inch thick polystyrene.

 

In winter it leaks heat like a sieve and in summer its like a greenhouse.

 

I managed to improve it this winter by putting down 50mm of celetex on the floor and under the gunwales, but its still a problem.

 

I'm struggling for head space as it is in the boat, and 50mm on the ceiling will be too much.

 

I could do the walls though, but should I stick it on top of the existing walls, or strip everything back to the shell.

 

And is there a super thin insulation I can put on the ceiling.

 

Or, is there a good way of preventing the greenhouse effect. Our roofs already painted cream, which I must admit helps, but today it was 10C hotter inside than out.

 

 

[onionbargee]

not insulation as such, but........

 

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CFMQFjAA&url=http%3A%2F%2Freviews.wickes.co.uk%2F9987-en_gb%2F210022%2Freviews.htm&ei=iQqIUc-ZH6-g0wWS9oH4Bw&usg=AFQjCNHDU1gzkQzbbFoYaFJUkTn0kDM8Pg&sig2=wuDGixKAgwtfQ_IbgLXFbQ&bvm=bv.45960087,d.d2k

[Doodlebug]

I read that it only works if you have a large air gap, although I cant work out if infrared radiation can pass through solid objects. So will it actually work if its mounted above the ceiling.

 

Its just made me think though, a mirrored ceiling would make the boat look much larger.

[The Bagdad Boatman (waits)]

Kingspan has a very high insulation value and is impervious to water vapor. Out there somewhere is a multi layer cloth type with foil and fabric, not cheap though. www.superquilt-Insulation.com

Edited May 6, 2013 by The Bagdad Boatman (waits)

[Grace and Favour]

If youhave an air gap - even a tiny air gap, between the insulation and your boat steel - you will create condensation on teh interior steel faces.

This moisture will then cause rust and lining damage

[smileypete]

Hi all,

 

Our boat really wasn't build for live aboards, the insulation is less than an inch thick polystyrene.

 

In winter it leaks heat like a sieve and in summer its like a greenhouse.

 

I managed to improve it this winter by putting down 50mm of celetex on the floor and under the gunwales, but its still a problem.

 

I'm struggling for head space as it is in the boat, and 50mm on the ceiling will be too much.

 

I could do the walls though, but should I stick it on top of the existing walls, or strip everything back to the shell.

 

And is there a super thin insulation I can put on the ceiling.

 

Or, is there a good way of preventing the greenhouse effect. Our roofs already painted cream, which I must admit helps, but today it was 10C hotter inside than out.

Best thing is doors, side and roof hatches, fans help too. Did you lose some headroom by putting 50mm insulation on the floor?

 

The multifoil stuff works best over ceilings and under floor, though it really needs an airgap on at least one side. With multifoil or kingspan/celotex boards, if it forms part of a proper continuous vapour barrier, by taping any joins and holes with foil tape, there should be little or no condensation problems.

 

cheers, Pete.

~smpt~

Edited May 7, 2013 by smileypete

[Ex- Member]

Tricky problem, bad insulation is a nightmare.

 

If you would prefer not to remove linings then I would suggest injecting with spray foam, it's about the best chance you'll get of filling these gaps where polystyrene is currently situated. You'll need lots of cans of spray foam, but buy in bulk and it's surprisingly cost effective. Use the larger canisters which require a screw on gun and buy some gun cleaner as well which will save lots of time.

 

The gun nozzil's are usually around 10mm so you can drill 10mm holes through the lining where appropriate and plug them after. being able to do a section at a time makes things easy too, you don't need to put too much foam in either, some expand quite a lot 50x or so the can capacity. You can drill a series of holes and inject one end and wait until it oozes out of one of the other holes, you can judge the fill time by doing this so not to waste foam.

 

This Everbuild stuff is supposed to be really good

 

http://www.ebay.co.uk/itm/Everbuild-Gun-Grade-Foam-750ml-Box-of-12-FREE-DELIVERY-/130477046950?pt=LH_DefaultDomain_3&hash=item1e6109bca6

[system 4-50]

Tricky problem, bad insulation is a nightmare.

 

If you would prefer not to remove linings then I would suggest injecting with spray foam, it's about the best chance you'll get of filling these gaps where polystyrene is currently situated. You'll need lots of cans of spray foam, but buy in bulk and it's surprisingly cost effective. Use the larger canisters which require a screw on gun and buy some gun cleaner as well which will save lots of time.

 

The gun nozzil's are usually around 10mm so you can drill 10mm holes through the lining where appropriate and plug them after. being able to do a section at a time makes things easy too, you don't need to put too much foam in either, some expand quite a lot 50x or so the can capacity. You can drill a series of holes and inject one end and wait until it oozes out of one of the other holes, you can judge the fill time by doing this so not to waste foam.

 

This Everbuild stuff is supposed to be really good

 

http://www.ebay.co.uk/itm/Everbuild-Gun-Grade-Foam-750ml-Box-of-12-FREE-DELIVERY-/130477046950?pt=LH_DefaultDomain_3&hash=item1e6109bca6

you need to use the fire rated foam which does cost a bit more.

[Doodlebug]

Yes, we lost headroom when we did the floor, but it was ok because we had room to play with, but another loss of headroom could be a problem.

 

How would we use the spray foam though, because it would only fill the gaps where there isn't any polystyrene really we need to take that out before using it.

 

How much better would an inch of spray foam be compared with an inch of polystyrene?

 

The thermal blanket stuff sounds good, although I dont know how the air gap would fit.

 

I wonder if a mirrored ceiling would help reflect heat inwards. As well as making the boat look huge

[Ex- Member]

Yes, we lost headroom when we did the floor, but it was ok because we had room to play with, but another loss of headroom could be a problem.

 

How would we use the spray foam though, because it would only fill the gaps where there isn't any polystyrene really we need to take that out before using it.

 

How much better would an inch of spray foam be compared with an inch of polystyrene?

 

The thermal blanket stuff sounds good, although I dont know how the air gap would fit.

 

I wonder if a mirrored ceiling would help reflect heat inwards. As well as making the boat look huge

Well it depends on the gap in the cavity, many boats had a 2 inch cavity and 1 inch of polystyrene floating around in it. If that's the case the spray foam will fill that gap pressing the polystyrene tight to the hull sides and filling any other gaps. Spray foam is more efficient than Polystyrene. If mixed though and fills the cavity, then together it will be more efficient than you have now.

 

Mirrors reflect light not heat.

[Doodlebug]

It must reflect heat as well otherwise the reflective insulation wouldn't work.

 

We just have a 1 inch gap full of insulation, maybe I could still remove it then use the spray foam.

[system 4-50]

It must reflect heat as well otherwise the reflective insulation wouldn't work.

 

We just have a 1 inch gap full of insulation, maybe I could still remove it then use the spray foam.

Quite difficult I would think to guarantee that you left no voids. In insulating my gunnels I boarded them & then drilled 8mm holes at 3 inch intervals (vert & horiz) and squirted them. I find it often doesn't expand as much as you would expect.

I would recommend building a sample setup & practicing before you go down this route.

[Ex- Member]

It must reflect heat as well otherwise the reflective insulation wouldn't work.

 

Well it does but not to the degree of reflective insulation which will have insulator properties within it's core. A glazed tile will reflect heat to a point, generally glass needs to be specially treated to be able to reflect heat as is common now in home glazing systems. In addition a mirrored ceiling will become a nightmare problem for condensation in an already poorly insulated boat.

 

Spray foam is more efficient than polystyrene however at just 1 inch it's only a slight gain in performance on polystyrene. The ideal cavity is 2 inch 50mm at this thickness you can get decent quality insulation materials that will perform well at a thickness of 50mm and gain over 90% insulation value. At 25mm in reality you'll never achieve adequate insulation, if spray foam is applied perfectly through out the boat at 1 inch thick then you'll achieve a max 70% however in your situation and not being able to ensure complete & full coverage unless removing the linings I would assess you would be very lucky to achieve 60%

 

Also bearing in mind the majority of heat loss is through the roof, then applying 50mm there, I would personally make a priority.

[Doodlebug]

Hmm, im not sure what I should do then.

 

The 50mm under the floor was an improvement, in winter I could literally feel the heat being sucked downwards, and so it deffo helped.

 

I could reduce the size of the floor, at the moment there is an old oak flooring under the current floor so I could gain 15mm.

 

I could fit 25mm of celotex, Really what I need is 'self finishing' insulation, i.e. the visible surface is part of the insulation, so that I dont need the extra space the plywood takes up.

 

I need something like polystyrene tiles over celotex, although it would look horrible.

[Odana]

Bubble foil sheet is a few mm thick but equivalent to 50mm polystyrene . You can then board over it.

[nb Innisfree]

Whatever insulation is used the insulating element is trapped air, in the case of sprayfoam or Celotex/Kingspan it's in the form of inert gas

bubbles, so the thicker the air or inert gas the better.

 

If the lining can be removed I would stick Celotex or Kingspan to primed steel making sure it protrudes more than any steel bracing and stick your choice of lining straight on top with aerosol foam making sure the foam fills the gaps between insulation sheets so covering the bracings. I've seen 4 mm ply stuck on like this and it made a rreally solid finish, so solid you could thump it and it felt like you was thumping the actual steel.

[Ex- Member]

Bubble foil sheet is a few mm thick but equivalent to 50mm polystyrene . You can then board over it.

 

Many have been duped by this nonsense, bubble foil is no better than any other insulation at the same thickness, in fact it isn't even an insulation material. The R values for this product are highly misleading, as an insulation it is actually only R-1 if you calculated it as an equivalent to proper insulation. If you want to know some truth about this product I would read hear. It certainly wouldn't be applied on my boat even if it was cheap. It does have it's uses and is a decent enough product for certain applications as this website points out.

 

Apologies try this

 

http://www.just-insulation.com/productselection.html

Edited May 9, 2013 by Julynian

[smileypete]

Yes, we lost headroom when we did the floor, but it was ok because we had room to play with, but another loss of headroom could be a problem.

 

How would we use the spray foam though, because it would only fill the gaps where there isn't any polystyrene really we need to take that out before using it.

 

How much better would an inch of spray foam be compared with an inch of polystyrene?

 

The thermal blanket stuff sounds good, although I dont know how the air gap would fit.

 

I wonder if a mirrored ceiling would help reflect heat inwards. As well as making the boat look huge

Celotex/Kingspan boards are about 40-50% better than normal polystyrene for a given thickness, but it's usually 2x more expensive or more.

 

Would have thought insulation above ceiling pays back better than under the floor as heat tends to rise, though heat loss is probably more noticeable at floor level. Above the ceiling linings maybe wide strips of 1" Celotex board would work, stick to the roof with blobs of gripfill etc and then fill in between with cans of sprayfoam, maybe tape with foil tape too for good measure.

 

Probably worth a trawl of Ebay to see if there are sellers locally selling excess stuff cheap, failing that there are some good deals if you buy 10 boards, maybe split with someone else or sell the excess yourself. Or try the local discount builders merchants in case they can do a good deal or match Ebay prices.

 

The performance of foil type insulation depends greatly on it's orientation and airgaps, it works very well when the direction of heatflow is down, and where there's awkward shapes like a curved ceiling. If you can get some of the quilt type multifoil stuff cheap it might do well over the ceiling lining, the cheap silver bubble wrap isn't that much good but should be worthwhile under floor without losing headroom, especially as there's often an airgap between bearers and ballast/baseplate.

 

BTW if the boat has single glazed bus windows, then try some of that heat shrinkable glazing film, it can make a bid difference to heat loss and draughts. Even 'porthole plugs' might be worth a go.

 

Sooo, summing up I'd probably finish off with 1" Celotex/Kingspan type boards, with 2" or 1" doubled where poss, then underfloor when the opportunity arises use aluminium bubble stuff or Celotex between the bearers, to recover some standing room.

 

cheers, Pete.

~smpt~

Edited May 9, 2013 by smileypete