Large tiles need special attention because, if the floor surface is not perfectly even, you will find the tiles may not sit flush with each other. There are two ways of overcoming this problem. One way is to completely resurface the floor either by rendering or by using a self-levelling compound. The other way is to use the Go-Tile-It System method which I will now explain to you.
image/text credit: Roy Southby
This video shows how to lay large tiles on an unprepared , uneven concrete screeded floor without using a self levelling compound.The Superspreader used in this video has been redesigned to incorporate a fold-over which reinforces the spreader and alleviates the necessity to apply any further reinforcement as mentioned in the video.
The large-format tile also has its installation challenges. Working with large-format stone requires tighter tolerances in the substrate. In addition, its weight makes it harder to handle in both floor and wall applications.
Generally, if your floors still remain uneven after levelling, it is either because the product used is of inferior quality or an insufficient quantity of levelling compound has been used. If you skimp on the quantity of bags applied, your floor may still be uneven.