Qué tipo de material utilizan los beliceños para construir sobre el agua?

The question is:

"What kind of material do Belizeans use to build on water?"

In Belice there is a type of construction called "Palafitos", which are houses build above calm water, sustained for  

wooden beams, this type of construction is done primarily with wood, but there may be other materials used, like metal and straw (for the roof).