How long does the screed need to dry before installing vinyl flooring?

Vinyl is to be laid in the living areas. The painter does not want to start yet - the screed has been there for about 4 months - because he thinks it is not dry enough yet. Afterwards, bubbles might form and then everything would have to be torn out again. Apparently, you can tell because the screed still looks patchy. Is that correct?

For such questions, there is a standardized residual moisture measurement. After the measurement, you know exactly whether you need to wait or can already proceed with covering.

@ "Heidi1965": It is really unbelievable how the lines of argument turn out! However, I assume that you did not make a typo and in the above posting you did not accidentally write "months" instead of "weeks". In this case (of a typo) it could well be that a cement screed (not calcium sulfate screed) has not yet sufficiently dried. Please accept: a screed (is it a cement screed or a calcium sulfate screed?), which after 4 months of laying time under normal conditions is not dry, meaning: ready for covering, will never become dry (and therefore ready for laying). Please ask the painter on what basis (residual moisture measurement method and with what result) he relies on his view that the subfloor is not yet dry. If he does not use the term "CM measurement" in his answer, then you know at least that the delay in floor covering installation is not due to the subfloor, but only due to the installer himself. Regards: KlaRa