They will also see their morning break restricted to 15 minutes. In return their working week is reduced by 30 minutes.
The reforms are part of a new pay deal struck between the Building & Engineering Services Association (B&ES) and the trade union Unite.
Under the new B&ES operative national agreement, which relates to mechanical operatives across the building engineering services sector, a wage increase of 2.5% on all hourly rates will be applied from Monday 6th October 2014.
This will be accompanied by a corresponding rise in daily travelling allowance and Premium Rate 1 and Premium Rate 2 (which are used to calculate overtime rates), and in other allowances and provisions, including death, disability and accident benefits.
A second increase of 3% in the hourly rate and associated benefits will be introduced from Monday 5th October 2015.
The employers’ contractual pension contribution will also rise, to 4% of basic pay in October 2014, to 4.5% in October 2015 and to 5% in October 2016.
The agreement also introduces a reduction in the working week from 38 to 37.5 hours, a cut in the morning tea break to a quarter-of-an-hour, and the abolition of the afternoon tea break.
The one element of the agreement that comes into force immediately is an increase in sick pay.
B&ES head of employment affairs and skills Peter Rimmer said: “As well as providing operative labour cost certainty over the next two-and-a-half years, the new arrangements significantly enhance productive time by removing the afternoon tea break and limiting the morning break to 15 minutes.
“This has allowed a small reduction in the length of the working week which, effectively managed, should also lessen the need for overtime working.”
He added that the settlement continued the development – which had begun in 2009 – of the contractual entitlement of employees to participate in an employers’ contributory pension scheme.
“The association and the trade union have undertaken to continue their discussion of longer-term issues regarding pension provision under the agreement, including a more structured approach to securing employee contributions,” Mr Rimmer added.