On January 21, 2016, NSERC CREATE Heritage Engineering hosted a one-day workshop organized by the Working Group on Repointing Mortars for Masonry in Canada. Held at Carleton Immersive Media Studio, Carleton University, the workshop attracted 42 participants from private sector (19), government (12) and academia (11). Ten students participated, including three in the NSERC CREATE program and others interested in conservation and material treatments. The workshop provided an exchange of information on recent developments in the repointing and repair of mortars in historic masonry buildings and structures in Canada.
Mario Santana and Mariana Esponda of Carleton University welcomed participants and provided an introduction to the NSERC CREATE Heritage Engineering program. Ken Trischuk of the National Research Council introduced the Working Group on Repointing Mortars for Masonry in Canada. Since 1998, the Working Group has provided a platform for the exchange of knowledge and practical experience with a high-level, technical approach to the study and repair of historic mortars. It brings together scientists, technicians and professionals involved in the research and study of historic mortars to present and discuss advances in the field. A special focus of the group is the reciprocal exchange of research and technical knowledge to inform conservation practice.
The workshop comprised two sessions: updates on research developed over the last two years in Canada; and the presentation of case studies. Three updates on ongoing projects were provided in the morning session:
- Lyse Blanchet (Heritage Conservation Directorate) spoke on the performance of repointing mortars;
- Paul Amaral, Katherine Buckley and Ann De Mey (Heritage Conservation Directorate) presented a statistical approach to the evaluation of mortar performance in situ; and
- Ken Trischuk (National Research Council) gave an update on NRC mortar-testing projects in the East and West Blocks of Parliament Hill, Ottawa.
During the afternoon, five case studies were presented on the challenges of repointing:
- Ann De Mey of HCD, PWGSC discussed repair versus restoration, and the use of Portland cement versus NHL mortars;
- Philip Sawoszczuk of King Packaged Materials Company spoke about his work with density measurements of cements, lime and sand, and batching by volume or mass;
- Marc Côté of MLC Heritage Masonry explained his results in freeze-thaw cycling and the use of de-icing salts;
- Fernando Pellicer presented his work in applying Polymer Modified Mortars in interventions in Montreal churches;
- John G. Cooke of J.G. Cooke Associates explained the damage that Portland cement has produced in Lock 43 at Kingston.
In keeping with the goals of the NSERC CREATE program, the workshop promoted the exchange of information between students and practitioners in heritage conservation. It provided an important opportunity for learning about recent advances in the repair of mortars and the challenges involved in interventions and permitted attendees to identify gaps in existing research.