The UK's top 20 construction companies are facing a collective pensions deficit of more than £1bn.
A Building investigation reveals many firms are struggling to control the mounting debt in their final salary schemes. A volatile stock market and longer life expectancies means it is likely firms will have to consider closing schemes and replacing them with less generous alternatives.
Most firms have already closed the schemes to new entrants, replacing them with money purchase or defined contribution schemes.
Industry bodies have expressed concern over the massive debt and have backed the right of companies to close final salary schemes.
Peter Commins, chairman of the Construction Confederation, said: "Final salary schemes are simply unsustainable in the current market. I think most employees will be realistic about this, given such a huge deficit."
Simon Storer, external affairs director for the Construction Products Association, said that the government should be taking the lead. "We can't drive our own way out of this. The Treasury needs to take control and offer guidance."
Industry bodies were also concerned that companies will expect a quick-fix solution to the problem and warned that firms will instead need to chip away at the massive deficit.