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How Terrazzo Works

Terrazzo Installation: Groundwork

No matter which type of terrazzo you choose, it's all going to be more intensive than putting in carpet or hardwood. Many types of flooring lend themselves to weekend projects or DIYers -- terrazzo isn't one of them. Unless you happen to be a mason. If you want terrazzo installed in an existing building, you need to call in contractors who specialize in it. Each one goes about it a little bit differently. While I've laid out the three main and most common types of terrazzo, there are all sorts of variations and contractors have their preferences and specialties. So let's pretend you're going get terrazzo.

First, your contractor will have to assess your current sub-flooring. If you want traditional terrazzo, you'll need a thick concrete base. That might mean excavating down under your house, because there's that sand layer on top of the cement before the actual terrazzo topping is laid and naturally you want that to jive with the existing floor level in the house. That's a lot of time and money spent, but if you're having it installed outside, it might not be as big of a deal. If you have a concrete slab already and you're getting polyacrylate or epoxy terrazzo, it'll just need to be checked to be sure it's sound and level. Your contractor will also locate existing joints in the concrete. And some types of epoxy terrazzo can be laid on top of plywood sub-flooring -- what many of us are most likely to have in our homes.

But let's go with the concrete slab, shall we? Workers will clean it, repair any defects, and prepare it for the type of terrazzo you're getting, a process known as creating the CSP (concrete surface profile). A thicker type, like traditional terrazzo, requires a rougher concrete surface, while thin-set systems like epoxy can go on a relatively smooth surface. You may also need a special membrane onto top of the cement to help prevent cracking, or in the case of epoxy terrazzo, to act as a moisture barrier.

If you're going with traditional, next you'll get the layer of sand, then a layer of cement, and then onto the design. But with polyacrylate and epoxy, it's straight onto the design. That'll all be planned out ahead of time, of course, differ depending on the type of terrazzo. Some contractors will print out the design on paper and lay it, full-sized, onto the floor. How detailed do you want it? Color changes in the design are separated by dividing strips, which might be made out of plastic, copper, zinc, brass or other materials -- the color can be part of the design, and they might also be different thicknesses. Really intricate designs might be laid out on panels of wire mesh ahead of time, or even use templates cut with water jets, while the rest is bent on-site. Workers solder joints together and then glue or otherwise attach the dividing strips to the concrete. The end is in sight...