Ms Geraldine Larkin:

I thank the committee for the invitation to assist in its deliberations on the issues before it. I am the CEO of the NSAI. I am accompanied by my colleagues, Ms. Yvonne Wylde and Dr. Ken Murphy. We are here today to assist the members in their work and address any questions they may have. In this session, we will give an overview of work that the NSAI was requested to undertake by Government, pursuant to its letter of 15 February 2022, including a review of IS 465. At the outset, I would like to acknowledge the homeowners, representatives of whom this committee has already heard from today, and the impact that issues with defective concrete blocks have had and continue to have on them and their families. I would like to assure all stakeholders that the NSAI and its technical committees, which comprise voluntary experts, have made and are continuing to make every effort to expedite work while maintaining integrity of the process.

On the review of IS 465:2018 and its application, at our previous appearance before this committee in December, the NSAI confirmed that work is under way by the relevant NSAI technical committees to inform the revision of IS 465:2018, and that this work would address requests by Government to consider matters related to deleterious materials such as pyrrhotite, and other matters including questions around foundations and insulation raised by the working group on the defective concrete block grant scheme, which comprised a broad range of stakeholders including homeowners representatives, local authorities and Government agencies. At that time, the NSAI also noted that the requested work is critically dependant on further technical information becoming available. The NSAI can now advise that substantive progress is being made through the defective concrete block technical matters steering group, chaired by the Department of Housing, Local Government and Heritage, to procure relevant data and research to advance knowledge for this work.

As a result, we can confirm that research programs are now under way to establish the long-term impact of pyrrhotite in walls, rising walls and foundations, which will inform consideration of the structural performance of retained blockwork post remediation. Analysis of the defective concrete blocks, DCB, grant scheme reports is under way and data-gathering and analysis is continuing. Following an open call to identify other data sources, substantive data relating to dwellings currently outside of the DCB grant scheme have been recently procured. This data will be analysed in conjunction with data available from the relevant local authorities from DCB grant scheme applicants. Modelling of behaviour of full-fill insulated walls has been carried out and those results are being considered. Substantive progress has been made on establishing a research programme to explore the long-term efficacy and longevity of alternative remediation options currently referenced in IS 465. The output from these research programmes will also be used to inform other questions raised by Government, including the question of consistency of interpretation of test reports, and criteria defining categories for remediation. In conjunction with this work a review of the guidance associated with the design and construction of masonry concrete block walls is also being carried out. Research referenced above will inform the evolution of associated European and national standards and-or guidance, by providing further technical insight into performance of aggregates, blocks, and blockwork construction.

The revision of SR 325, recommendations for the design of masonry structures in Ireland to Eurocode 6, will be informed by an extensive range of climate-related research and data procured, or being procured, including recently updated climatic data from Met Éireann; the modelling of moisture ingress through concrete block walls; and impact of freeze-thaw and other climatic conditions on the long-term integrity of masonry wall construction.

In its letter of February 2022, the Government also requested that the NSAI consider such other matters as the provision of guidance on procurement, certification and traceability of concrete blocks, consideration of a minimum cement content for blocks, consideration of a maximum specification for content of deleterious materials, and a review of the impact of pumped cavity fill and related guidance in the SR 54 code of practice for the energy efficient retrofit of dwellings. SR 54 is being revised following a systematic review and this, together with other work previously referred to will be informed by relevant learnings from the research programs under way.

It should also be noted at this point that experts serving on the NSAI technical committees for the above work are very conscious of the need for timely updates of work outcomes, and they therefore keep under continuous review the possibility of issuing interim guidance, should this be considered useful or proportionate. The NSAI understands fully its important role in relation to these standards and all standards developed by its technical committees right across the broad spectrum of standards for construction. I hope this statement has given members an overview of our work and we are happy to address any further questions they may have.