An Etymological Dictionary of the German Language/Estrich
Estrich, m., ‘floor, plaster-floor, pavement,’ from the equiv. MidHG. ęstrĭch, ęsterĭch, OHG. estirĭh, astrĭ(hh), m.; comp. MidLG. astrak, esterck, Du. estrik (these two forms are not recorded). In Middle Germany the word, which was unknown to Luther, is not found. Perhaps it is really native to the valleys of the Rhine and Danube, being introduced by Roman colonists. Comp. early MidLat. astricus, astracus, ‘paving,’ Milan. astregh, Sicil. astracu, Ital. lastrico; OFr. astre, Fr. âtre, ‘hearth,’ lit. ‘pavement.’