The $4 household item that could save your home in a flood

Dale Stevens Lake Conjola’s home was flooded in 2025. Picture: Thomas Lisson

---

A $4 household staple could be the surprising trick that helps keep floodwater out of your home, with scientists finding duct tape can outperform sandbags in an emergency.

New research has found the everyday item, already sitting in many kitchen drawers and toolboxes, slashed water leaking through doors by up to 98 per cent during flood testing.

Scientists at the University of Hull found common duct tape and specialist sealing tapes were significantly more effective than sandbags at reducing the amount of water pushing through doors during a flood or major rain event.

MORE NEWS

Named: Suburbs with toxic drinking water

‘Hear next door take a piss’: Tradie’s shock housing truth

‘Deflated’: Gran hit with $42k council tree bill

In laboratory testing, flexible synthetic rubber tape reduced water leakage by 99 per cent compared with an unprotected door, while standard duct tape cut leakage by 97 to 98 per cent. Sandbags, by comparison, reduced leakage by about 70 per cent at their most effective.

Professor Stuart McLelland, professor of water science, said the findings could offer “immediate benefits” for households looking for a quick, cheap way to reduce flood damage.

Three doors, ready for flood-testing. (Stuart McLelland)

---

“We captured any water that leaked through the door in a sealed enclosure behind the door, as we increased water depth in 5cm increments to a maximum depth of 60cm,” he wrote in an article published on The Weather Channel.

“We pumped out any water that leaked through the door and continuously measured the rate of water leakage to evaluate the performance of doors and different types of protection applied to them.”

The Hull University research team tested a variety of commercially available tape on a number of different doors.

---

The testing found even the worst-performing tape still reduced leakage by 80 per cent, while taped outward-opening doors generally performed better than inward-opening ones.

For unprotected doors, leakage often reached thousands of litres an hour at 60cm of water depth.

“For unprotected doors, leakage often reached thousands of litres per hour at 60cm water depth. Applying duct tape across the external door reduced that leakage by 97-98 per cent. Specialist sealing tapes achieved even greater reductions,” Professor McLelland wrote.

The findings challenge the long-held view that sandbags are the best emergency option when floodwater is approaching.

Researchers said sandbags have practical drawbacks.

They are heavy, messy, labour-intensive and difficult to dispose of once they have come into contact with contaminated floodwater.

Most households also do not have a ready supply sitting at home.

Source: University of Hull

---

During the tests, researchers stacked 54 sandbags with plastic sheeting between the sandbags and the door.

Even then, sandbags were outperformed by tape-based sealing methods.

“In our tests, sandbags provided less effective protection against leakage through tested doorways compared to the tape-based sealing methods,” Professor McLelland wrote.

The cost difference is also stark.

Many Australians may already have a roll of duct tape at home, while buying one from a hardware store such as Bunnings would cost as little as $3.99.

Sandbags, by contrast, can involve sourcing, transport, lifting and disposal costs.

Still, researchers warned tape is not a miracle fix and should not be seen as a replacement for proper flood protection.

Professor McLelland said duct tape was not a substitute for professionally designed flood doors, barriers or a property-specific flood resilience plan.

Prof Stuart McLelland and his team replicated low-level flooding.

---

However, it can minimise water damage restoration costs, which typically sit between $1500 and $8000 for residential properties, while major structural flood damage involving contaminated water or entire ground floors can exceed $10,000 to $30,000, depending on the size and clean-up needs.

“It is a temporary measure that may reduce water entering through particular gaps; it cannot guarantee a dry home or prevent water entering through other routes, including walls, floors, and drains,” he wrote.

“Its effectiveness will depend on the condition of the door and frame, the surfaces to which the tape is applied, the quality of the seal and flood conditions.

Sandbags reduce water leakage by about 70 per cent at their most effective.

---

“For properties at significant flood risk, professionally assessed protection remains important. For others, low-cost temporary measures could provide an additional layer of protection, though they cannot guarantee a property will remain dry.”

The broader message, researchers say, is that improving flood resilience does not always have to begin with a major investment.

“A ($3.99) roll of duct tape cannot stop a flood. But our research suggests it could help keep out some of the water entering through a doorway. And that makes it a useful part of a wider plan to be prepared before the water arrives,” Professor McLelland concluded.