Guides
Sealed or unsealed is the wrong first question
Almost nobody sells unsealed terrazzo and almost everybody talks about it as if they did. The real question is which binder you have, because that decides whether sealing is possible at all.
“Is it sealed?” is asked in almost every specification conversation, and it is nearly always the wrong question, because the answer is a property of the binder rather than a decision somebody made.
With a cement binder, sealing is possible and expected
A cement-bound matrix is porous. Water absorption is one of the four figures the grade is set by — 8.0, 6.0, 4.0 or 1.0 per cent depending on the class — and a penetrant is applied to slow what that porosity does.
The question that follows is not whether to seal but with what, and how often.
With a resin binder, there is nothing to absorb
An epoxy terrazzo does not take a penetrant in the same way. It is already the densest thing on this site by a wide margin — which is also why it is chosen where chemicals, water and heavy traffic are the problem.
So “is it sealed” has no useful answer until the binder is named.
Where the question goes wrong commercially
A supplier who answers “yes, sealed” to an unsealed question has said something the specification did not ask. A supplier who answers “no” has said something the buyer may not have meant. Both are answering a question about marketing rather than about the floor.
The useful sequence is short. Which process. Which grade or binder. Then, and only then, what protection that system takes and how it is maintained.
A related confusion worth naming
Sealing and antistatic resistance are different requirements, measured by different methods, with different thresholds. A floor can satisfy one and not the other, and a specification that treats them as one item is underspecified in a way that only surfaces at the test.
What we do not say here: no sealer product is named and no maintenance interval is given. Both belong to the binder and the ambient conditions rather than to terrazzo, and a number here would be wrong on most sites.
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