PIR on solid wall - roll-own w/Seconds or PIR+PB pricey?

[jason1958]

I need to insulate 4m^2 wall.
The wall is solid double brick, pebbledash, 2ft eaves overhang.
The wall sits between 2 cavity walls, with one cavity wall being just 3ft long where it meets a 2x4" mortar debris infill bay window w/pebbledash.

The 4m^2 wall does not seem damp, browning under plaster is fine.
However the underfloor by the bay further along has a slight damp odour.


Going PIR+PB...
- Kingspan say K17 dot-n-dab. That is £150 from Jewsons, the only place that will sell me two sheets of 50+12.5mm. That's quite a price. No-one else locally has it, online will only ship 5 sheets which at £250 is better value but no use to me with PB on it.
- Kingspan go on to say K18 on tanalised batons as solid walls CAN get damp.

Rolling my own...
- Seconds do Kingspan Foil-50mm-Foil for £12 a sheet.

Q - Can I just screw that to batons, then through-screw plasterboard and skim over?

I'd actually prefer a PIR without PB on it as lighter to handle.

Thanks.

 

[jason1958]

A quick examination showed browning/plaster of min 32mm depth.

So a load of genuine Marmox 50mm seconds with Mapei Keraquick on the wall gets a cheap & waterproof insulation solution.

That will have to wait, other stuff to finish first...