They’ve taken dirty nappies and used them to replace some of the sand needed to build a house with concrete.

Siswanti Zuraida and her team collected used nappies, cleaned them up, and treated them with chemicals to get rid of any bad germs. Then the nappies were dried and shredded into small pieces that could be added to concrete.

The researchers tested out their idea by making different mixes of concrete with various amounts of shredded nappies. They found that this new kind of concrete was just as safe and strong as regular concrete. It also didn’t have any harmful germs in it.

Overall, the scientists say that nappies could replace up to 8% of the sand used in the concrete needed to build a house. In the parts of a house that support a lot of weight, 10% of the sand could be replaced with shredded diapers. In areas that don’t have to support much weight, as much as 40% of the sand could be swapped out for nappies.

The scientists didn’t just test the strength of the concrete. They actually built a small concrete house to test their ideas in real life.

The researchers think their idea could make it less expensive to build homes.