Thinnest insulation possible for roof.

[jtylr]

Have been looking at and reading about narrowboats for the last few weeks and have seen a couple that will potentially work. I am on the taller side at 6’2 and wondering how much extra head room it’s possible to eek out of the cabin during fit out without getting into welding things. One of them for example has polystyrene insulation taking up approx. 3” of space - could this be reduced using something more modern?
 

I have a bit of time to find something with enough headroom, however with my budget restricting me to older used narrowboats It would be nice to know if getting an extra inch out of one is realistic or not.

 

I have looked into the idea of having some kind of box/skylight added to wherever the kitchen ends up as I figure that is the only place I’ll spend a lot of time standing up, but would be dependent on the boat I ended up with as if it’s has a bit of character don’t really want to go spoiling the lines (or getting stuck in tunnels!)

 

 

Edited March 23, 2021 by jtylr

[LadyG]

Thinsulate  on a roll would be thinner, its just a fabric, but you'd need to check the insulation values, roof insulation keeps heat in, in winter, prevents condensation, also helps to cool the boat in summer, of course.

Are you intending to replace existing deckhead (the lining), aka ceiling, sounds like a major job.

I don't think Houdini Hatches are going to work.

You could also go barefeet or hotel style slippers! Just sayin'......     

 

Edited March 23, 2021 by LadyG

[ditchcrawler]

The gap between the steel top and the "ceiling" will be the thickness of the battens its fixed to plus the thickness of the rib the battens fixed to, so you chances of saving an inch are slim for a lot of work.

[jtylr]

Thank you for the replies (and correction of terminology - still waiting for ‘the narrowboat builders book’ to arrive!). I did suspect the chances of getting much more out of it were going to be slim.

 

Search continues...!

[Machpoint005]

The boat we used to have a share of was built to have extra headroom for that very reason. It was slightly inconvenient for those of us of more reasonable height, but at least such boats do exist. Don't expect them to be advertised as such, because the increased air-draught would be perceived as a negative for many punters.

[David Mack]

1 hour ago, jtylr said:

One of them for example has polystyrene insulation taking up approx. 3” of space - could this be reduced using something more modern?

I would be surprised to find 3" of insulation. 1-2" would be more normal for polystyrene. That said, the boat construction may have resulted in a gap between the roof plate and the ceiling lining of 3", but if that is the case you can't easily do anything about it.

[jtylr]

Yeah I was thinking more along these lines for the kitchen area for kitchen area if required, at a slightly more sensible (lower) height.

 

 

18 minutes ago, David Mack said:

I would be surprised to find 3" of insulation. 1-2" would be more normal for polystyrene. That said, the boat construction may have resulted in a gap between the roof plate and the ceiling lining of 3", but if that is the case you can't easily do anything about it.

It may well be 2”. I measured through a gap in the lining and got 8cm but was unable to ascertain the thickness of the wood or if the polystyrene was hard against the steel.

Edited March 23, 2021 by jtylr

[Mike Tee]

Look for a boat with thicker than normal (10mm) baseplate. Occasionally they come up for sale with 12.5mm (1" in old money) or 15mm - more baseplate can mean less ballast so no need for deep underfloor area.

I meant 1/2" for 15mm but it won't let me edit the post!!

1 minute ago, Mike Tee said:

Look for a boat with thicker than normal (10mm) baseplate. Occasionally they come up for sale with 12.5mm (1" in old money) or 15mm - more baseplate can mean less ballast so no need for deep underfloor area.

I meant 1/2" for 12.5mm but it won't let me edit the post!!

 

[Alan de Enfield]

4 minutes ago, Mike Tee said:

Look for a boat with thicker than normal (10mm) baseplate. Occasionally they come up for sale with 12.5mm (1" in old money) or 15mm - more baseplate can mean less ballast so no need for deep underfloor area.

I meant 1/2" for 15mm but it won't let me edit the post!!

 

 

 

The OP has said his budget restricts him to looking at 'older' NBs which are unlikely to have much more than 8mm base plates.

 

I suppose it depends on his definition of 'budget' and 'older'.

 

I had a 1998 Reeves NB that had a 13mm base plate in which my 6'3" Son could easily walk down the centre - even allowing for the additional height by 'rolling onto your toes' whilst walking, which can lift your height by a couple of inches.

[Dav and Pen]

12.5mm is nearer 1/2 inch. 

[TheBiscuits]

21 minutes ago, Dav and Pen said:

12.5mm is nearer 1/2 inch. 

 

Keep reading ...

[Slim]

6' 2" is not that tall. I'm 6' 2" as was my dad, my nephew is 6' 4". We have had a family holiday cottage in Devon for 50 years + where the living room ceiling is about 6' in places. The kitchen ceiling is a similar height. It's something you get used to very quickly. Not so the door between the two, that's about 5' 10". The front door iis even less. Before getting too bogged down with the issue I suggest you try a few boats. 

I should add that I've been on any number of NBs in the last 25 years and never found my height an issue. Equally I'll admit to shrinking a little in the last few years

[Jackofalltrades]

5 hours ago, jtylr said:

Have been looking at and reading about narrowboats for the last few weeks and have seen a couple that will potentially work. I am on the taller side at 6’2 and wondering how much extra head room it’s possible to eek out of the cabin during fit out without getting into welding things. One of them for example has polystyrene insulation taking up approx. 3” of space - could this be reduced using something more modern?
 

I have a bit of time to find something with enough headroom, however with my budget restricting me to older used narrowboats It would be nice to know if getting an extra inch out of one is realistic or not.

 

I have looked into the idea of having some kind of box/skylight added to wherever the kitchen ends up as I figure that is the only place I’ll spend a lot of time standing up, but would be dependent on the boat I ended up with as if it’s has a bit of character don’t really want to go spoiling the lines (or getting stuck in tunnels!)

 

 

 

I'm a whisker under 6'3" so I feel your pain. It's tough living in a 5'11" world.

 

I doubt you could gain an inch of extra headroom on a boat that's already built & fitted out. It would be a tremendous amount of work even if you could.

 

I looked at quite a few secondhand boats and most of the newer ones were OK for headroom but that's with 1" (if you're lucky) of spray foam on the ceiling. But I never went on a boat without thinking, this needs doing, that needs changing, why did they do that, WTF is wrong with people, etc. So in the end I chose to go the Shell* > DIY build route. I can get exactly what I want and blame no one but myself if it goes horribly wrong.

 

* Construction of the shell has been delayed due to Covid, allegedly. They have my build slot deposit and were paid the rest of the build deposit last week...

 

 

[Bee]

You will not manage to gain more than 1" on the ceiling without getting cold spots or lines where the battens are. 2" is really the minimum from the steel plating to the headlining.  There is probably an inch or so under the floorboards to be gained but oh, the work. Its not far short of a rebuild. The pic. of a 'clerestory' roof is a nice idea and very attractive but shockingly expensive to do.

[TheBiscuits]

5 hours ago, jtylr said:

I have looked into the idea of having some kind of box/skylight added to wherever the kitchen ends up as I figure that is the only place I’ll spend a lot of time standing up, but would be dependent on the boat I ended up with as if it’s has a bit of character don’t really want to go spoiling the lines (or getting stuck in tunnels!)

 

Cut a hole in the floor ...

 

 

 

 

It's not quite as silly as it first sounds, despite the old joke about the donkey's ears and the low bridge.

 

I did this in my galley to create a wine cellar and additional storage by making trapdoors in the floor and removing the paving slab ballast in that area.  If you make the trapdoor, you can stand on the baseplate when you're washing up and have the extra height without changing the roof profile.

 

Whether this is practical does depend on where the steelwork below the floor is in relation to your galley.  You wouldn't want to be tripping over the stringers or bearers.

 

My baseplate is about 5 inches below the finished floor if that helps.

 

 

[Bee]

Used to drink in a pub with a low ceiling. Dartboard was  about 1` too low so you lifted up a panel in the floor, climbed down a step and chucked yer darts. Felt really weird though.

[jtylr]

59 minutes ago, TheBiscuits said:

 

Cut a hole in the floor ...

That was my idea for the shower tray ?

[cuthound]

7 hours ago, LadyG said:

Thinsulate  on a roll would be thinner, its just a fabric, but you'd need to check the insulation values, roof insulation keeps heat in, in winter, prevents condensation, also helps to cool the boat in summer, of course.

Are you intending to replace existing deckhead (the lining), aka ceiling, sounds like a major job.

I don't think Houdini Hatches are going to work.

You could also go barefeet or hotel style slippers! Just sayin'......     

 

 

The Thinsulate insulation on my boat is 2 inches (50mm) thick. It is different to the stuff in gloves.

[TheBiscuits]

30 minutes ago, jtylr said:

That was my idea for the shower tray ?

 

It's a sensible one.  Just remember to put some insulation under the tray or it'll be chilly to stand in, and it's probably best to leave just enough room to get a drain connection in there too!

 

[Ex Brummie]

Insulation doen't just keep the heat in. In summer, it also keeps the heat out, otherwise your boat can become uncomfortable. ( You might also burn your head!!!)

[nb Innisfree]

I had 1" of sprayfoam applied to Innisfree with 6mm ply strips over steel roof strengtheners then 6mm ply sheets over that, worked fine. 

[jtylr]

1 hour ago, Ex Brummie said:

Insulation doen't just keep the heat in. In summer, it also keeps the heat out, otherwise your boat can become uncomfortable. ( You might also burn your head!!!)

  

Solar array will sort that out

Edited March 23, 2021 by jtylr

[Glynn]

https://www.superquilt-insulation.co.uk/product/ybs-superquilt-multifoil-insulation/?gclid=Cj0KCQjwo-aCBhC-ARIsAAkNQiuxcUmmt7RONw7bNpcCnn_BPcapbl0fuyYTQ9UM9hGu8SQlTVpZyoUaAvkdEALw_wcB

[TheBiscuits]

1 minute ago, Glynn said:

https://www.superquilt-insulation.co.uk/product/ybs-superquilt-multifoil-insulation/?gclid=Cj0KCQjwo-aCBhC-ARIsAAkNQiuxcUmmt7RONw7bNpcCnn_BPcapbl0fuyYTQ9UM9hGu8SQlTVpZyoUaAvkdEALw_wcB

 

Thickness: 40mm (7mm Compressed)

 

40mm when unpacked isn't very thin.

[jtylr]

5 minutes ago, Glynn said:

https://www.superquilt-insulation.co.uk/product/ybs-superquilt-multifoil-insulation/?gclid=Cj0KCQjwo-aCBhC-ARIsAAkNQiuxcUmmt7RONw7bNpcCnn_BPcapbl0fuyYTQ9UM9hGu8SQlTVpZyoUaAvkdEALw_wcB

 

I did see something similar (ecotherm I think), but then read somewhere that without the air gap the R rating decreases quite considerably. Think it might take a bit more than thin battens + ply to compress too, unless someone knows how I can staple it to the steel!

Edited March 23, 2021 by jtylr