Ever wondered why pool tables are incredibly heavy? That’s (partly) because they’re built with one of the heaviest and most durable naturally-occurring materials on the planet: slate. Yes, underneath that greenish cloth on the best pool tables is a rock that you’ll also find in walkways and roofs.
The idea of using slate as a pool table surface mainly comes from tradition, though it is easy to see why the earliest pool table makers chose this material. Unlike many types of rocks, slate is actually composed of hundreds of sediment layers, making it incredibly durable yet relatively easy to polish at the same time. Most pool tables use a 0.75-inch thick slab of slate, while the pricier ones used in professional pool tournaments have 1-inch thick slate surfaces.
Some pool tables use a single piece of slate, while others have a three-piece bonded slate surface. The latter is arguably the best because a bonded surface makes the table more resistant against warping.
However, since slate is rather expensive and difficult to obtain, some pool makers have begun using other materials like synthetic slate, honeycomb plastics, and medium density fiberboards. While they’re invariably cheaper, these non-slate materials don’t provide the same performance and durability as genuine slate surfaces.