The head of a major construction company believes skill shortages will strike the Christchurch rebuild in waves.

A recent industry report into demands on the region's subcontractors has found most are struggling with skill shortages and staff poaching.

Most subcontractors reported an average 30% turnover in staff.

Master Plumbers national president Martin de Gouw said there's a high turnover of young workers across all sectors.

"The willingness of people to stay with one particular trade is not actually there. They have a lot of not only turnover of staff, but also people leaving the industry, a lot more than it was 20 years ago."

Leighs Construction managing director Anthony Leighs said the skills needed will change depending on the stage of the rebuild.

"There was a massive shortage in painting and plastering type trades, due to the demands of the residential repair programme. What we're seeing now is an acute shortage in mechanical services."

Anthony Leighs said the growing construction sector in Auckland is also pulling people away.