Thought I'd revisit this basic skill to see what people thought was the current best way to achieve a good long lasting solution to internally insulating a solid wall.
I'll give my preferred methods, feel free to critique it and offer alternatives stating the benefits.
Non vapour open.
Foam boards
On solid brick/block wall with good existing prepared plastered finish and render or brick external finish.
Using lamented plasterboard comb a tight coat of bonding adhesive on to the wall and fit board , foam perimeter.
or
Using insulation board do similar but then fit vertical batons over with fixings through into the wall to create a service void the fix plasterboard to them.

Vapour open option
Wood fibre boards , fixed with lime adhesive , mesh lime plaster top coat

I'm with Tony - but there's always a doubt about fixing the pbd to the EPS, once they know it can't be dotndab thinking. So it's interesting to hear mechanical fixings 'later'.

an02ew of this forum invested in a spider-web spray keg of contact adhesive - spray both the substrate and the board back. One spray of 30% coverage leaves 70% vapour-open; the other 30% spray leaves 70% of that 70% open = 49% vapour-open overall. But 30% of 30% glue area = 9% only!

Certainly not to try glueing anything to foil faced Cellotex or similar - it'll easily pull the foil off the board.

Posted By: fostertomI
Certainly not to try glueing anything to foil faced Cellotex or similar - it'll easily pull the foil off the board.

Ive tried various diy lament ideas over the years and found contact adhesive on foil back to work ok , I think with a high coverage it must give an overal tension that's different from say pulling from just one corner , in which case its easy to pull the foil off.
Ive used dot and dab bonding adhesive *(tight comb for airtightness) as well but added mechanical fixing due to worries about long term fix. again though its held well when stressed tested by me pull and knocking it without fixings.

Re battens on the inside of the insulation, the danger is that wind or air from outside gets into this void bypassing all the insulation and for me raises all the same heckles as dot and dab then.

deleated

Sorry, bit of a misread from me.

Posted By: tonyRe battens on the inside of the insulation, the danger is that wind or air from outside gets into this void bypassing all the insulation and for me raises all the same heckles as dot and dab then.

As it'll be on the warm side and used to hold the insulation to the wall as long as every things well sealed prior to the final installation of plasterboard I think its ok.
with a lamented solution you still get the problem of getting the cable through from the cold side (if that's where they are) or cutting into the insulation for the runs if doing it warm side.
i understand your concerns re dot and dab , Ive seen issue many time with penetrations into the cavity not sealed and draught running behind the PB but hopefully those doing the refurb insulation will be interested in making sure thats not the case prior to covering.
I guess I like it because it seems to me to give a bit of extra security to the structure and good fixings for both insulation and PB , much like the method commonly used in pitched roof insulation for attaching the under rafter layer of board.

Posted By: tonyRe battens on the inside of the insulation, the danger is that wind or air from outside gets into this void bypassing all the insulation and for me raises all the same heckles as dot and dab then.

In the details I've seen for such a construction, the main airtightness barrier/VCL is placed inside of and immediately adjacent to the surface of the insulation (indeed it might be the foil surface, suitably taped at joints) so there should be no air at all passing from outside to the inside. The battens and resulting service void are often held to protect the airtightness layer against accidental penetrations, although that does rely on nobody using long screws.