expansion joint

Hi, We are getting the ground floor tiled - apx 80sqm in a bunch of rooms - and need to check a few things: Where do i need to put expansion joints? We have screed on the floor with the fibres, and in some places this has cracked over the past few months - should i put the expansion joint...

There is something I do not understand and would be grateful for clarification. The idea of a control joint is to allow a wall to move and therefore prevent it from cracking. At the same time we put rigid elements such or a bond beam that prevent movement. Do we really need control joints in...