Owning your own home

So back to insulation, here is the internal shiz.
If I put PIR or wool slab between the framework and then 9 or 12mm plywood over the top am I going to create some kind of condensation trap that is bad?

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My goal is to keep it as stable temp wise as possible so my bikes don't go rusty and also make it look a bit nicer than a shed inside. I'll not be doing anything in there like turbo, maybe some light mechanic work.

Sort of - general timber frame for habitable space depends on stopping moisture get to the frame with a VCL under the wall sheathing - all taped and sealed up and not penetrated. You then have a breather membrane (tyvek) on the outside under the cladding which allows any vapour to escape and stops water getting in to the frame.

I think PIR plus foil taping all joins and over the frame itself is probably easiest here. (Leave an air gap on the cladding side ideally).

If you do seal it up you need air change (trickle vent )- to vent moisture that occurs internally (wet bikes etc).

think @andos did this to his log cabin/shed - I had planned to but been lazy...

@Señor_Bear yeah I did something similar with my shed.

I used 50mm PIR, made level with the lowest point of of the roof "joists". Sealed everything like crazy with foil tape and clad with T&G. I made sure there was ~50mm between the PIR and the roof to allow for ventilation, then I drilled little holes and regular intervals and capped them with these little circular vent covered to stop flies etc for getting in.

I feel like it's kind of working - we heat the space up a lot to make it possible to work in there. During the heavy snow up here the snow remained for quite some so the insulation must be stopping the heat leaving.

A sensible thing. I still haven't got round to doing my guttering. Or a green roof.
The double doors are useful shade providers in the hotter summers.

Thanks for this. I only have 50mm deep in the framework so would have to go basically flush with the wood faces both sides. I might just do it and see what happens.

Maybe just add some kind of vapour barrier and give a generous coat of Sika Wood preserver on the insides.

I honestly have no Idea what I’m doing with this stuff though. I’m sure it’ll be fine, you are clearly VERY competent with this stuff!!!

I’m average at best.

Related to the insulation discussion above, has anyone got experience with insulating suspended timber floors? We are looking into replacing the floorboards in our draughty 30s house so would be an ideal time to put down some insulation.

My mate did this. Netting in between the floorboards and then filled with wool.

Thanks, that’s what other websites seem to suggest as well. Did your mate have any issues with damp after installation? Some suggest this could be an issue but we have quite a deep crawl space so hope it won’t be an issue for us

Seems not but he’s only been in the house for 3 months

If you use actual wool the moths will eat it.

I've just done one with netting and mineral wool. Fitted a couple of air bricks at the same time, couple more being added at the front when we remove cladding and insulate the front room.

Covered in a breathable membrane mainly to stop too much crap getting into the insulation. Have checked under the floor a couple of times and things seem dry enough at the moment.

Had some ridiculously good help a few weeks back when I viewed a house in st werbs in Bristol. Thanks all. Can't believe how quickly it sold and do wonder what it went for.
Viewed this today, which went up at 25k more a few weeks back and sold before the board even went up. Buyers (family) pulled out because it needed structural work (I think cracking in the walls on one side, but I didn't see anything).

https://www.rightmove.co.uk/properties/81499906#/

Had been a HMO, currently empty. Windows and door are horrible but easily fixed. Kitchen looked okay. Electrics, no idea but most rooms had one socket only. Waiting on the estate agent to send the survey over. Worst bit, someone extended downstairs (where the bathroom is) and got rid of the courtyard garden in so it just has that tiny channel.

Took one photo

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looks better than the last one you posted and (subject to survey) superficially speaking looks like it might only need a rewire and redecoration, with a kitchen upgrade at some point too. need to wait and see what survey says and would try find out more about that 'cracking' - sounds ominous

I really want to use wool but concerned about this aspect!

All modern sheeps-wool insulation has been mothproofed. Most is treated with a chemical called Thorlan, which conforms to ISO 3998. You can also get a non-chemical treatment called Ionic Protect which changes the cellular structure of the wool so they can't eat it.

Somebody should tell Rapha about this shit.

You would need to factor in the cost of removing the fake stone cladding & disposing of it in an active volcano though

It looks certainly better than the previous one, the lack of garden i dunno is either ideal or a nightmare. Depends how you look at it.

I only have 50mm deep in the framework

25mm?

When I was contemplating doing our shed I was looking at thinner PIR for the same reason. 25mm seems to be the most common "thin" one.

You can then put better insulation for the roof, especially as in your case you've said the extra headroom is unnecessary.

@cozey yep agree cheers. Did notice the gutters were a bit ropey and not hooked up at the back. Hoping to have the survey soon

@TW grim isn't it! Been looking into this and people seem to do it patiently with a chisel then get bricks repointed