How is the thickness of the bottom board important? It sounds really easy which it also is. The bottom board is the fundament of every cat tree. The thicker, thus heavier the bottom plate is, the more stable the whole construction will be. There are a lot of competitor models that have a base of only 0.8 cm. In our point of view, this is not enough. Petrebels bottom boards are
at least 2cm high and go up to 5cm! This is what Petrebels calls a solid base!