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Answers

Can terrazzo be a wall panel, and what does it need behind it?

Yes, and the substrate is decided by weight rather than by the fixing. A bonded cement terrazzo wall system is 2-1/4 inches including the topping and runs 18 to 22 pounds per square foot, which is roughly 88 to 107 kg per square metre. That does not go on plasterboard. It goes on cement board or a heavy-duty backer board.
Six terrazzo processes, drawn to one scaleEach column shows the layers of one terrazzo process. Precast and cement-bound are thick; epoxy is thin; porcelain is a fired body. Dimensions are published ranges, not our measured figures.substratePrecast20 mmsubstrateCement-based12 mmsubstrateEpoxy5 mmsubstratePoured10 mmsubstrateLiquid3 mmsubstratePorcelain9 mmSections drawn to one scale from published ranges. Our measured figures are listed separately.
The six processes drawn to one scale. Layer thicknesses are published ranges.

The figures, and where each one comes from

System Build-up Weight, lbs/sq ft What it fixes to
Bonded cement wall 2-1/4 in incl. topping 18 to 22 cement board or heavy backer
Epoxy wall 3/8 in 3 to 4 a prepared slab or board
Our thin panel 8 to 12 mm ⛔ not stated, we hold no figure ⛔ ask, it depends on the size

Why the processes are not interchangeable

NTMA sets out the weights that make wall terrazzo an engineering decision: the bonded system is the one specified for interior and exterior walls and it is heavy, because the topping is ground into a system rather than stuck onto the wall. The practical consequence is the substrate. A plasterboard wall carries a fraction of what a cement board carries, so specifying a terrazzo wall over the wrong board is not a fixing detail — it is the wall failing. This is also where a thin panel changes the calculation, and where we do not help ourselves: the weight of our own band per square metre depends on the panel size and we do not publish a figure we have not measured.

What these figures are, and what they are not

The bonded build-up and weights are from the NTMA Terrazzo Systems Reference Guide; the kilogram equivalents are our conversion and EVIDENCE.md section H gives the factor. ⛔ NO WEIGHT IS QUOTED FOR OUR OWN THIN PANEL, because it varies with size and we have not published a measurement; ⛔ and no panel fixing capacity, substrate specification or pull-out figure appears anywhere, because those are determined by the panel and the wall together and we hold no test data on the assembly.

Measured data sheets and test reports

If you are specifying this

These are the forms we actually supply for this question, with production photographs where we have them:

Send a specification Ask for a sample