Applying duct tape to the outside of a household door reduced water leakage by 97% to 98% during controlled laboratory tests, according to new research from the University of Hull. The findings offer a low-cost, practical alternative for homeowners preparing for property floods before water reaches their doorsteps.
The UK government’s 2025 FloodReady Review called for affordable measures to help households understand and prepare for flood risks. Stuart McLelland, deputy director of the Energy and Environment Institute at the University of Hull, noted that the best time to protect a property is before floodwater arrives.
Laboratory Door Tests Measure Leakage Rates
Researchers at the University of Hull tested modern wooden, uPVC, and composite household doors installed by trade professionals inside a laboratory. McLelland and his colleagues increased water depth in 5-centimeter increments up to a maximum depth of 60 centimeters. They captured and pumped out water that leaked through the doors, continuously measuring the leakage rates to evaluate different protection methods.
For unprotected doors at a 60-centimeter water depth, leakage frequently reached thousands of litres per hour. Applying duct tape across the external door frame reduced that volume by 97% to 98%. Specialist sealing tapes achieved even greater reductions, according to the research.
The same individual applied the tape for all tests to minimize human bias, with each application taking between 10 and 20 minutes. Specialist flood putty tape provided an even tighter seal when applied to the outside, flood-facing side of the door.
Duct Tape Outperforms Traditional Sandbags
For decades, sandbags have served as the default emergency response to rising floodwaters. However, laboratory testing revealed significant practical limitations compared to tape-based sealing methods.
Researchers stacked 54 sandbags with plastic sheeting placed between the door and the bags. At their most effective depth, sandbags reduced leakage by only 70% compared to an unprotected door at the same water depth. Sandbags leaked because they are stacked rather than sealed.
Beyond performance differences, sandbags are heavy to transport, labor-intensive to deploy, and difficult to dispose of after contacting contaminated floodwater. Households rarely keep a supply of sandbags ready for immediate deployment.
The cost disparity is substantial. A household can purchase a roll of duct tape for £10 or less, or may already own one, whereas sourcing and deploying sandbags involves significant additional transport costs and physical effort.
Property Insurance Shifts and Future Resilience
The research intersects with changing dynamics in the insurance sector. Jonathan Kassian, head of flood resilience at Flood Re, stated that sandbags remain a symbol of flood protection, but these laboratory tests turn that assumption on its head. UK insurers are increasingly encouraging flood-risk clients to keep high-quality tape on hand and learn proper application techniques.
Duct tape is not a substitute for professionally designed flood doors, permanent barriers, or property-specific resilience plans. It functions solely as a temporary measure to reduce water entering through doorway gaps and cannot stop water infiltrating through walls, floors, or drains.
Effectiveness depends on the condition of the door and frame, surface materials, and flood conditions. For properties facing significant flood risk, professionally assessed protection remains essential. For other homes, low-cost temporary measures add an extra layer of defense as part of a wider preparation plan that includes monitoring flood warnings and securing utilities.
Frequently Asked Questions
How long does it take to apply duct tape for flood protection?
In University of Hull laboratory tests, applying duct tape to an external household door took between 10 and 20 minutes per door when executed by a single tester.
Can duct tape entirely prevent water from entering a house during a flood?
University of Hull researchers emphasized that duct tape is a temporary measure that reduces doorway leakage by 97% to 98%, but it cannot guarantee a dry home or stop water from entering through walls, floors, or drains.
How do specialist sealing tapes compare to standard duct tape?
Flood Re testing indicates that specialist flood putty tape achieves an even tighter seal against water intrusion than standard hardware-store duct tape.