In our new house, I have 100mm blockwork downstairs which will be dry lined (12mm boards I assume) and skimmed (dot and dab) What width frame should I fit? Also I have 90mm studwork up stairs which will be faced with plasterboard (12mm I assume?) and skimmed- again what width frame should be fit??
Howdens standard sizes are 4.5 inch (which is only about 4.25 inch when measured!!) or 5.5 inch which is probably about 5.25 inch measured!! Please can you advise. Also should they be fit before plasterboarding or afterwards ??