The contractors used aluminium-backed insulation. On top of all the other stuff too. Vodafone sim in my work device gives off 1 bar and really poor readings in the cell info app, Three contract - my personal device gives off 1 bar and equally poor readings and my partners o2 simmed device gives off again 1 bar and poor readings all round. Signal increases slightly nearer windows as expected and increases dramatically outside the properety.
Thanks for all the help, I'll press ahead with the device you bought and post back in what may be a few weeks with the results.
