Workshop insulation and interior cladding

[DigitalM]

The workshop that I'm planning on setting up will be in an existing outbuilding build (roughly!) as follows

7m x 3.5m
Concrete slab which will get a resin coating
Timber frame walls (2x4 I think) with ash lapped cladding.
Timber A frame roof with old brick-coloured tiles (hmmm, not very good with materials am I)

The roof has clearly refurbished recently, and is lined inside with some sort of plastic membrane and looks quite professional.

Anyway...

The frame walls are currently insulated with some sort of old polystyrene foam that has broken down in places and is leaving small white pearl sized bits in various places and quantities both inside and outside, and I think should be replaced and updated. Then I'd like to clad the inside to add a little strength to the structure and give it more of a finished look, along with acting as a place to secure floor standing cabinets and various tools.

I'd be grateful to hear some opinions on what to use for insulation from a heat and noise perspective, and what to clad the interior with.

Currently there is some interior cladding that was done with MDF, it looks at least a decade old and while there are some signs of water penetration in places, it's fairly minimal.

 

[Shultzy]

It will depend on the distance between the vertical studs, as an odd size is better filled with the "solid" insulation like Kingspan which is less wasteful. 100mm (4") Rockwool is probably the cheapest and will fit in with your 2"x4" covered in 1/2" mdf painted white.

 

[DigitalM]

Ah I see, that makes a lot of sense - shows what a complete noob I am at this sort of building! I'll have to strip a load of the current MDF off and see how uniform they were with the frame! Thanks!