Qadad

Imagine a special kind of plaster, like super-thick paint, that people used to make buildings strong and waterproof. That's Qadad! It's made from lime, which is like chalk, mixed with oils and fats. This amazing mixture has been around for over a thousand years. It’s so good at keeping water out, it’s like a superhero shield for buildings!

How did they make this magical plaster? They mixed lime with special ingredients like volcanic ash. This ash is like tiny, super-strong rocks that help the plaster stick together and become waterproof. It takes a very, very long time to prepare, sometimes over 100 days, and even longer to dry completely. It’s like baking a giant, super-slow cake!

Why is Qadad so important? Because it helps buildings last for a super long time, even in wet weather. It protects them from rain and keeps them cool. This means people can live and work in these buildings safely for many, many years. It's like giving a building a special coat that keeps it safe and sound.

You can still see Qadad on very, very old buildings. There are even parts of an ancient dam, called the Marib Dam, that were built with Qadad over a thousand years ago and are still there today! This shows just how strong and amazing this ancient building material is. It’s a real piece of history you can still see.