Shed insulation...a final word?!

[lizziegrace]

Hi!
Newbie here and just after some consolidation of advice (if you can get such a thing?!). I've read through the multitude of posts regarding insulating sheds for more "homely" use and just wanted some clarification that I've got it right before we go ahead and commit to buying stuff )
So, firstly the shed is 12'x8' apex and good height, heavy duty timbers (3x2) and treated wood throughout (15mm shiplap walls, felt on roof), 2 single glazed windows, laid onto slab base.

Am I right in assuming the following would be good:
Kingspan type insulation + polythene + ply is best way to insulate walls, leaving no airgap
Floor treated same way but with 50mm polystyrene instead of kingspan
Secondary glaze windows and draughtproof door
Add vents in top and bottom to encourage airflow
Install gutter and downpipe from roof
Internal heater/dehumidifier would also help

Am I on right track? This will be a shared music/art room for non-children related stuff so we want it lovely!!!
Thanks for anyone who can help )

Lizzie

 

[mattylad]

Sounds about right.
I did this on my shed when I was 19, had a radio shack at the bottom of the garden. Spent many cold nights out there talking all over the world. (over 20+ years ago)

Fully treated the wood, lined with polystyrene & then I had chipboard walls, power points etc, IP66 ish fluorescent light, burglar alarm & intercom to the house.

I was only 19 & knew nowt so took the power through steam piping underground (proper piping joints though).

Why not kingspan under the floor? I'd have thought that it would be better as it has a foil lining & can better retain heat/stop the cold from below.

I'd also consider secondary glazing (if you cant dg them) the windows as single glaze will let a lot of heat out/cold in.

Take the door locks & hinges you get with it off & throw them away, then fit better & more secure ones with a strong steel plate or thicker wood on the inside & use tamper proof screws.
You may have nowt valuable in there but some scrote will try & break in damaging it just to see.


I wish I had another shed...

 

[lizziegrace]

Thanx for your reply...good to know we're on right lines ) Will have to see how budget goes for all kingspan...
Anyone know of airgap is needed in walls/roof or not?
Thanks
Lizzie

 

[oilman]

A dehumidifier with ventilation is like standing under a waterfall with a mop and bucket.

It is better to have permeable insulation and walls so the moisture can migrate through. I used sheeps wool insulation, no impermeable membrane, and plenty of ventilation. That way the temperature stays reasonably stable, and for the most part things are dry.

 

[lizziegrace]

Hmmm...interesting ) Dh ad seen that sort of stuff on sale in local DIY store. Now I'm really confused!

 

[Jandiy]

If you want a cheap easy to fit solution for secondary glazing the window you can fix a clear acrylic panel to the window using specialist strips or magnetic tape. You can find prices etc on the omegabuild website. Regards

 

[Deluks]

It is better to have permeable insulation and walls so the moisture can migrate through. I used sheeps wool insulation, no impermeable membrane, and plenty of ventilation. That way the temperature stays reasonably stable, and for the most part things are dry.

This is not the best solution. The reason for the vapour barrier is to prevent moisture from migrating through the structure, as it does so in the form of water vapour (steam), which will come off of wet objects and bodies/breath. On a cold day, if the temp is higher inside the structure the moisture travels through the walls to the cold side of the insulation where it condenses before it's had a chance to pass through the entire structure. This makes the outside of the insulation and back of the exterior cladding damp. Leading to mould growth and rot.

Unlikely to be a problem in the summer months but will be an issue around this time of year where the temperature drops significantly during the night.

You did mention that you have plenty of ventilation which will help, but having so much that you offer the least path of resistance to the vapour will simply make the building draughty and negate the purpose of the insulation in the first place.

 

[SOSAGES]

Sorry to dig up an old post.

I was going to build my internal shed(office) walls like this. (working outside in)

Outside Wall (about 45 mm thick wood)
breather membrane (ultraperm?)
Gap of 1inch
new frame work for wall built with foil front/back insulation in between (kingspan etc)
plasterboard
Paint

Sound reasonable?