Search templates

Nice theme! Just started developing a site using it, and noticed that the search results and no-results are not displaying properly. The page header is not being picked up, and the text is full width instead of left column.
See e.g. https://websitesahoy.co.uk/particulart/?s=dioxin&submit=Search and https://websitesahoy.co.uk/particulart/?s=abcdef&submit=Search

Thanks, Clare