To prevent water from entering through a door during a flood, a simple strong adhesive tape could work better than sandbags.
When water levels rise, sandbags remain one of the best-known forms of protection. Yet they are heavy, take a long time to put in place, and are far from watertight. Researchers at the University of Hull in the United Kingdom wanted to compare their effectiveness with that of solutions that are easier to find in stores.
Sandbags stacked in front of house doors in Lamont, Iowa, before a flood in June 2008. Photo: Patsy Lynch/FEMA, public domain.
They installed six types of residential doors in a laboratory capable of reproducing a flood. Behind each door, they collected and measured the water that managed to get through. They then gradually raised the water level to 60 centimeters while testing different protective measures.
The most surprising result involved reinforced adhesive tape, often called duct tape. By covering potential paths for water around the outside of the door, the researchers reduced leakage by 97 to 98% compared with an unprotected door.
A special synthetic rubber tape performed even better, reducing leakage by 99%. The sandbags, although stacked in front of the door with a plastic sheet, were less effective: at best, they reduced leakage by 70% under these conditions.
Strong adhesive tape.
Pixabay
The side of the door also matters. Adhesive protections worked much better when placed outside rather than inside. Doors that open outward also resisted leakage better than those that open inward, even without additional protection.
Why does adhesive perform so well? Sandbags slow the water down, but often leave gaps between them or along the frame. Tape, on the other hand, can directly cover the small spaces through which water seeps. In the experiments, the researchers took about 10 to 20 minutes to apply it.
However, simply putting down a few strips is not enough to make a house watertight. The results concern specific doors in a laboratory, with the water level limited to 60 centimeters. During a real flood, water can enter through walls, vents, or other openings, and the pressure can damage the structure.
The researchers therefore present these tapes as an additional temporary protection, not as a replacement for professional equipment or safety instructions. Their study mainly shows that for limited water intrusion around a door, a simple and inexpensive solution can sometimes prove highly effective.