The Ireland construction sector contracted at the fastest pace since mid 2013, data from the IHS Markit showed Monday.
The Ulster Bank construction Purchasing Managers' Index fell to 46.2 in October from 48.3 in September. A score below 50 indicates contraction in the sector.
This was the second consecutive monthly fall and the most marked since June 2013.
"The recent easing of concerns regarding Brexit crashout risk may offer some support for construction confidence and activity in the months ahead," Simon Barry, chief economist Republic of Ireland at Ulster Bank, said.
Housing was the only monitored sub-category to record an expansion in October. Commercial activity declined at the fastest pace since June 2013.
At the same time, civil engineering contracted for the fourteenth straight month in October.