Help re Insulating a wooden shed with Kingspan/Celotex

[Levitric]

Thank you, that is the most straightforward reply I have had. Is something like Tyvek ok for the external membrane?
I have also read that a moisture membrane is recommended after the insulation underneath the inner wall. But again am confused

 

[Levitric]

Thank you, that is the most straightforward reply I have had. Is something like Tyvek ok for the external membrane?
I have also read that a moisture membrane is recommended after the insulation underneath the inner wall. But again am confused

Or would Tyvek be ok for the inside also?

 

[Fitzroy]

Tyvek is fine for outside, not inside. Inside you need a vapour barrier to prevent any warm moist air getting to the cold side of the insulation where the moisture can condense. OSB is an effective moisture barrier due to the glue content, plaster board is not, I’ve not seen anything conclusive for ply. Vapour barrier is normally a polythene 0.1-0.2mm thick with joints taped. The thicker is easier to install without tearing holes in it, both offer plenty of barrier. Personally if I was using for occasional occupancy, few evenings a week and some hours on the weekend I’d forgo the vapour barrier. For high usage, eg every day during winter as a home office, I’d install a vapour barrier and a relative humidity meter, potentially needing ventilation or a dehumidifier. Converted sheds are not ideal high occupancy warm working spaces, they are just not suited to this. Purpose built garden offices have considerably more thought in their design.

 

[Levitric]

Again thank you for your answer, may use a vapour barrier and ply then. I want to use ply as it is easier to hang stuff on it.
I will not be using the shed everyday all day but I do spend more than the occasional hour in there. This last winter I spent time in my current shed which is completely uninsulated so anything that I can do is going to be better. I use it as a workshop for making stuff from wood mainly.

 

[harryc]

The silver foil on your Celotex is your vapour barrier.

 

[schnaumummy]

Hi all found this thread while trying to clear my confusion
I have a 12 x 10 44mm thick cabin. Its sat on a wooden shed platform so way off the floor ( concrete under it)

I need to insulate im thinking of celotex
So im simple thinking so be easy on me
So i need to have a breathable membrane against the wood interior walls? Then a gap? Then celotex and ply on top no gap?

Floor needs a waterproof membrane then celotex between the gaps floor on top?


The thread is very confusing

Can someone put it in laymens terms for me please

 

[Jameshow]

Hi all found this thread while trying to clear my confusion
I have a 12 x 10 44mm thick cabin. Its sat on a wooden shed platform so way off the floor ( concrete under it)

I need to insulate im thinking of celotex
So im simple thinking so be easy on me
So i need to have a breathable membrane against the wood interior walls? Then a gap? Then celotex and ply on top no gap?

Floor needs a waterproof membrane then celotex between the gaps floor on top?


The thread is very confusing

Can someone put it in laymens terms for me please

I would put a gap behind the cladding then celotex and osb / ply.
Imho you don't need a membrane aa the celotex has a foil one and the osb is one on the inside ! Unless it's being lived in / used to dry washing!!

 

[howardjennings]

Hi all found this thread while trying to clear my confusion
I have a 12 x 10 44mm thick cabin. Its sat on a wooden shed platform so way off the floor ( concrete under it)

I need to insulate im thinking of celotex
So im simple thinking so be easy on me
So i need to have a breathable membrane against the wood interior walls? Then a gap? Then celotex and ply on top no gap?

Floor needs a waterproof membrane then celotex between the gaps floor on top?


The thread is very confusing

Can someone put it in laymens terms for me please

This is how I built my playpen, sorry workshop.
These are the layers, from the outside in.
Feather edge fencing boards (horizontal)
Breathable membrane (roofing membrane)
4 x 2 stud frame.
PIR (celotex, Kingspan etc.) between studs.
Vapour barrier (sheet of polythene) over walls and ceiling. Completely sealing out draughts.
9mm OSB internal walls.
Ceiling is plasterboard.
Floor construction is
Damp proof membrane on concrete slab. Covering the floor and up the walls 300mm or so, to overlap the vapour barrier.
50mm PIR
22mm chipboard flooring floating but glued at joints.
Window and door are uPVC
Virtually all materials came from FB marketplace.

Hope that helps

 

[HamsterJam]

Hi all found this thread while trying to clear my confusion
I have a 12 x 10 44mm thick cabin. Its sat on a wooden shed platform so way off the floor ( concrete under it)

I need to insulate im thinking of celotex
So im simple thinking so be easy on me
So i need to have a breathable membrane against the wood interior walls? Then a gap? Then celotex and ply on top no gap?

Floor needs a waterproof membrane then celotex between the gaps floor on top?


The thread is very confusing

Can someone put it in laymens terms for me please

Have a look at the Tuin website. I insulated the roof and floor of my present and a previous log cabin using this method and not had any issues.
https://support.tuin.co.uk/hc/en-us/articles/213470549-Insulating-A-Log-Cabin

 

[SadGeek]

My shed is insulated with foil lined PIR. Stays warm but ruined wifi. I guess the foil acts as a Faraday cage.

I had to run a cable to the shed and fit a access point inside it.

 

[imageel]

My shed is bone dry - nothing rusts and wall construction is from outside -> inside

Cedar shingles
Tyvek
18mm ply
80mm studwork in-filled with foil backed celotex foamed between uprights and cross braces
15mm batten air-gap for electrics, ethernet
0.1-0.2mm thick polythene vapour barrier
6mm ply inner lining board.

Before I vented my chip extractor outside through a 150mm hole the place was so airtight that you could not slam the doors, after venting it I now have to open a window when the extractor is on otherwise it creates a mild vacuum and it is hard to open the doors....
I added an old Wifi AP so phone can get WiFi -it's 50m from my house but 3G seems to get in ok

See my post here -I forgot to add this was built in 2011 and moisture has never been an issue

Edited to add the Tyvek...

 

[MikeJhn]

Hi all found this thread while trying to clear my confusion
I have a 12 x 10 44mm thick cabin. Its sat on a wooden shed platform so way off the floor ( concrete under it)

I need to insulate im thinking of celotex
So im simple thinking so be easy on me
So i need to have a breathable membrane against the wood interior walls? Then a gap? Then celotex and ply on top no gap?

Floor needs a waterproof membrane then celotex between the gaps floor on top?


The thread is very confusing

Can someone put it in laymens terms for me please

Look up "Canadian Rain Wall" the construction details are very clear on some of the cross section post.