Dr Joan Walsh has a BSc in Chemistry and Mathematics from the National University of Ireland and a BSc in Geology from the University of Glasgow. In 1995 she was commissioned by Historic Scotland to survey all the slate quarries in Scotland with a view to identifying a new source of Scottish slate. This work formed the basis of her doctorate which she was awarded in 2000. The work was published by Historic Scotland as a Research Report, Scottish Roofing Slate: Characteristics and Tests, and a Technical Advice Note Scottish Slate Quarries.

Based on the findings of this research, the Scottish Stone Liaison Group extracted blocks of slate from quarries representing two different types of Scottish slate. The slates were tested using procedures developed as part of her doctorate.  The results of this work were published by Historic Scotland as two Research Reports: (1) Ballachulish Slate; Extraction and testing of slate from Khartoum quarry, Argyll. and (2) Macduff Slate; Extraction and testing of slate from the Hill of Foudland, Aberdeenshire.

From 2000 to 2006 she was a senior research fellow at the University of Paisley (now the University of the West of Scotland). The scope of her research expanded to include slates from the rest of Britain and slates imported from around the world. During that time she was the leader of a project on Improving materials testing and technical information in the UK roofing slate industry under the Partners in Industry Open 2002 Project sponsored by the Department of Trade and Industry.

She also acted as an adviser to Historic Scotland on the impact of the new European standard for natural slate on Scottish roofing practices.

In 2006 she became an independent consultant geologist giving advice to architects, builders and home owners on all matters relating to natural roofing slates. This included identifying the provenance of used slates, testing and reporting on the quality and performance of slates and interpretation of the European Standard for slate.  She gives frequent talks at seminars and workshops on roofing slate.