Hi there,

Thistle Hardwall is intended as an undercoat for wet plaster; so I wouldn’t recommend using it for bonding dry plasterboard to masonry.

There are two methods for fitting plasterboard to brick walls. The one I’m assuming you have in mind is called ‘dot and dab’. With this technique, you apply thick lumps of special dry wall adhesive (such as Gyproc Dri-Wall Adhesive) onto the masonry wall and gently press the board into position. Gyproc recommends applying the Dri-Wall adhesive in dabs 50mm-75mm wide and around 250mm long in three vertical rows for each board. There are various alternatives – Wickes has its own range of Gypsum-based plasterboard adhesive, for example.

The other option is to build out fixing points from the masonry wall using either strips of timber, an entire timber stud frame or a proprietary metal system. You would then attach the plasterboard to the timber/metal supports much in the same way as if you were building a simple stud wall. See https://www.self-build.co.uk/how-fit-plasterboard for a guide to fitting plasterboard to timber studs.

Hope this helps!

Chris (Deputy Editor & Online Editor, Build It magazine)