Internal wall insulation - Best Fixing Method

[goeddiegogogo]

I want to internally insulate the outward-facing walls of my victorian house (no cavity) in Dublin, but I have had some mixed messages from different sources about the best method. (Yes, There are some 4 year old posts on here about this but none are very conclusive. Can we make this post a good reference for others?)

- Googling "how to install internal wall insulation" some of the top posts use battens.
- I did a plastering course and the plastering trainer told me dot and dab is standard but I could batten "if I want" and if I did I could add extra insulation between battens.
- The builders' merchant told me that insulated board "can be fixed straight to the wall" and was surprised when I asked about battens.
- An architect told me "whatever you do don't fix it straight to the wall"

The wall is uneven and battening could be challenging, dot and dab would be much easier but I don't want to do something that won't last on the inside of a windy and rainy Dublin wall.

So, what's the truth? Is there a truth?

 

[noseall]

Solid (cold/damp vulnerable) walls are better battened. If you don't mind losing a wee bit off the room - fix a chunky top and bottom batten then fix smaller section uprights to these, in order to get over any lumps.

 

[wwwebber]

We installed insulation (50mm) backed plasterboard to the inside of our solid internal walls using dot and dab. Some of the walls were damp and the old batons had rotted. Lived there for 8 years before moving out - not a single problem. Nice and warm, quiet and no damp. We did remove all of the old plaster though.