Photo by Damian Gillie/Construction Photography/Avalon/Getty ImagesGetty ImagesShares in brick manufacturer Ibstock sank on Friday as tough market conditions forced it to cut expected full-year earnings estimates. At 122.8p per share, the FTSE 250 company was down 8.2% and the biggest faller on the UK mid-cap share index.Ibstock said that “a more uncertain near term backdrop in the group’s core construction markets has led to weaker than expected demand,” impacting off-take for both its clay and concrete pr ...