Suspended ceilings are very simple to install. The first thing you need to decide is the height of your ceiling, and then you need to fix the perimeter trim to this height. Once this is complete, the next step is to decide on the layout of the ceiling. As a rule of thumb using a 600x600mm system you should have the largest cut tiles as possible around the edge. For example if your ceiling is 2700mm long then your edge tiles should be 450mm wide (not 150mm wide), with an equal cut size on the adjacent side. There is a ceiling calculator that will help you determine the size of your edge tiles. Once you’ve determined the layout you need to fix the main tees (main support bars) at 1200mm centres using ceiling suspension wire. Then clip the 1200mm cross tees at 600mm centres inbetween the main tees and 600mm cross tees inbetween the 1200mm cross tees. For cross tees at the edge of the ceiling, professionals always use 1200mm cross tees, because they are slightly longer than two 600mm cross tees. To finish off its just a matter of fitting the tiles. Ceiling tiles can usually be cut very easily using a stanley knife and a straight edge. If all this sounds a bit too complicated, then you could always use a professional ceiling contractor.