With just over 9,000 votes cast out of more than 48,000, turnout was 18%.
Mr Murphy polled 5,475 votes. The other candidate, carpenter Jerry Swain, polled 3,529 votes.
Steve Murphy has been regional secretary of Ucatt’s Yorkshire region since March 2010 and was previously regional secretary for the Midlands since 2004. Mr Swain is London regional secretary.
Mr Murphy said: “I am honoured that Ucatt members have elected me general secretary. I thank them for their support. I want to work with all members, full time officials and staff so we can build a stronger union to represent workers across both the private and public sectors of the construction industry.
“During my period of office Ucatt will be a campaigning union tackling the rogue employers that blight our industry. But I will be willing to work with good employers to secure our members jobs, pensions and their futures.”
Acting general secretary George Guy said: “I am delighted that Steve Murphy has been elected. He will make an excellent general secretary. This was a critical election for the union and it is now the responsibility of all Ucatt members to unite behind him.”
Mr Murphy will formally take over as general secretary on Monday 9 January 2012.