During the three months to the end of September, Geberit sales fell 7.5% to 790.7 million Swiss francs ($788.33 million).
The company, seen as a proxy for the broader construction sector, also said it now expected a full-year core operating profit margin of around 27%, down from its August view of 28%.
It also tweaked its sales outlook lower, now expecting growth in the mid to high single-digit percentage range, down from its previous outlook for a high single-digit increase.
"This prudent outlook is shaped by the prevailing high macroeconomic uncertainties," Geberit said.
($1 = 1.0037 Swiss francs)Reporting by Noele Illien; editing by John Revill and Kim CoghillOur Standards: The Thomson Reuters Trust Principles.