Other tips;

3. If you raise your floor like mine (i raise 1 feet above), please fill with sand (as we know sand not 'takung water'). If possible do not fill with tanah or sampah sarap, usually contractor want save money, cause sand is expensive. Usually 'tanah' will 'mendap' as time goes, then there is gap between floor. Before concrete, let your sand fully 'mendap' by rain water or pipe water. Then after the sand mendap, then re fill any gap, then you can concrete after your sand is stabil.

Another reason not to use tanah or sampah2...is to avoid any water takung below your concrete.