Wooden lean to/Conservatory(?)wall insulation question

[reoreborn85]

Hi. Sorry if this is a dumb question but we moved into this house last year and it has a conservatory (Thats how it was described but i'd say it's a lean to).

The past owners said the whole thing is insulated except for the small right side. The wood on this side is rotten and i'll be replacing it in the next few weeks so i thought i'd add the insulation while i'm at it.. but i literally have zero clue on insulation. I've read SO many different advice sites and all give different answers. Some say use cotton wool as for something like this it'll have the same effect... while others say rock wool. Others say rockwool is awful and to use insulation slabs and leave a 1 inch gap between the slab and the outside wood. I've even seen some people say use plastic bags as for a wooden structure the previous two suggestions won't offer much protection (It's only single panes of glass) Etc.


Here is a photo of the lean to. It's from last year when we first moved in. Ignore the round square. The bit that needs doing is on the right side out of view. Next to the waterbutt. It's 1 meter in length and connects to the brick building you can see on the right.

If anybody can help or give advice i'd be very grateful.

 

[Deluks]

Insulation won't do a lot in a single glazed structure, but get some cheap cavity slabs from Wickes or whatever.
I assume the rotten wood is on the outside and you are replacing the cladding?
You will need a membrane of sorts over the insulation, and an air gap behind the cladding.

Probably best to remove the rotten wood first and then post a picture of what's going on behind it.

 

[reoreborn85]

Insulation won't do a lot in a single glazed structure, but get some cheap cavity slabs from Wickes or whatever.
I assume the rotten wood is on the outside and you are replacing the cladding?
You will need a membrane of sorts over the insulation, and an air gap behind the cladding.

Probably best to remove the rotten wood first and then post a picture of what's going on behind it.

I'm so sorry for the late reply. i didn't get any notifications of a reply!

Yep, the rotton wood is on the outside and has been removed. There IS insulation but it looks like cheap roof wool insulation about 2cm thick but it's in a plastic bag?! Never seen that before I have covered it back up and will be tackling it next weekend. So just replace it with cheap insulation then with a gap of air between that and the cladding? Nothing special?

 

[Deluks]

If you don't want to make a bigger job of it, then yes, just do that.
Maybe try and identify why it's rotten in that location first, gutter problem?
Looks like they need a clean.

 

[reoreborn85]

If you don't want to make a bigger job of it, then yes, just do that.
Maybe try and identify why it's rotten in that location first, gutter problem?
Looks like they need a clean.

Thank you for your help!
I think the main culprit is an overflowing waterbutt. You can kind of see it under all the brambles in that photo. It was over flowing on left side and had been for over a few years by the look of the mould and fungus. Looks like it just kept the wood utterly soaked. Thankfully the structure is mainly okay. We also seem to have a family of toads living IN the hole lol.

 

[Deluks]

Mould and fungus aren't good. Remove all rotting and soft timber, treat the rest with a wood preservative, and replace with treated timber.

 

[Deluks]

As for the toads in the hole, I hear they make a great Sunday lunch.