This part of a house is made from tiles or slate. It keeps the rain out. What is it?

What are things made from? They can be solid, like a brick, or they can be made of liquids or even gasses. Some things, like rock and wood, are natural. But other things have been made. The chair you are sitting on may be made of wood, but it has been made in a factory. Many things are made from lots of different materials.