Hi I am about to build up a concrete floor on an extension. I intend breaking up a mountain of old bricks and concrete for the hardcore. What size should I be looking to break them down to. Also once laid does it need to be compacted afterwards by machine or is it possible to do it by sledgehammer. ![Eek! :eek: :eek:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)