| Abstract | This report outlines a study funded by Architecture Sans Frontières Québec (ASFQ) and Canada Mortgage and Housing Corporation (CMHC) as part of the “Building for the Future” initiative. Flooding remains the costliest natural hazard worldwide, with damage exceeding US$320 billion from 2018 to 2023. Increasing instances of flooding, fueled by climate change, aging infrastructure and extreme weather conditions, present serious risks, particularly in Canada, where 80% of cities are located in flood-prone areas. With a significant proportion of Canada's real estate stock located in flood-prone areas, cost-effective solutions are essential to protect these properties. This project aims to: • Evaluate the effectiveness of Canadian building standards against the effect of floods. • Evaluate various temporary residential flood barriers under different conditions. • Develop experimental protocols in line with existing international standards.
Two phases of testing were carried out at the National Research Council of Canada (NRC): Phase 1: focused on assessing performance (leakage rates) through standard Canadian residential construction. Phase 2: evaluated the performance of various temporary opening flood barriers in two experimental setups.
Overview Phase 1: Standard residential construction (NBC, 2020)
1. Leakage behavior: a. Leakage rates were highest at between the sill plate and the foundation, followed by leakage between the door and its frame. b. Increasing water depth correlated with higher leakage rates, although wood expansion reduced leakage over time.
Phase 2 Opening barriers
1. Barrier performance : a. Proprietary barriers outperformed traditional measures (sandbags, plywood). b. Leakage rates for most barriers exceeded the levels suggested by ANSI 2510, particularly at greater water depths. c. Some barriers failed under wave action and debris impact due to displacement or detachment from the opening or component failure.
2. Influence of water level: a. Performance decreased as the depth of water above the opening sill increased. b. The main source of leakage was between the base of the barrier and its frame. Overflow, or wave overtopping only occurred for barriers that did not completely fill the opening and at the highest wave height.
3. Comparison with ANSI standards: a. Testing revealed discrepancies between actual performance and ANSI-certified results, highlighting the need for specific and localized testing, a need to investigate repeatability effects, and clearer testing guidelines.
Key findings and future recommendations
1. Improve test standards: a. Develop Canadian-specific test protocols to ensure barrier suitability and reliability under regional conditions. b. Establish clearer guidelines for barrier installation to minimize user error. c. The results of this study will be forwarded to the committee working on the development of a testing standard for perimeter barriers (CSA W212), with the goal of including opening barriers in a future edition.
2. Improved testing: a. Conduct repeated testing on various Canadian building envelopes to account for construction variability and develop an understanding of acceptable margins of error. b. Include interdisciplinary research on moisture damage and structural performance and integrity.
3. Public confidence: a. Increase transparency of experimental methods and results to build confidence in flood mitigation solutions. b. Promote education on proper installation and maintenance of flood barriers.
4. Training of highly qualified personnel a. The project contributed to the training and further education of four highly qualified personnel at INRS: two undergraduate research trainees and two PhD students.
This study highlights the critical need for adaptable, standardized flood protection measures tailored to Canadian contexts. While many of the proprietary flood barriers tested showed promise, performance inconsistencies under real-world conditions underscore the need for rigorous, standardized testing. The knowledge gained here has laid the foundation for future research, policy development and public adoption of effective flood mitigation strategies. |
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