Hi there, hubby and I are insulating our garage. It shares a wall with neighbouring garage. Party wall is single stud frame. The neighbours switchboard is on the shared/party wall. When we removed the plasterboard on the party wall we noticed a difference with the section backing the neighbours switchboard. Not sure what it is? It still looks like plasterboard but when we cut it, instead of white plaster dust is was a grey colour.
We have put in our earthwool insulation and are now up to replastering - what plasterboard should we put behind the neighbours switchboard? Iām guessing it was some type of fire check?