The skills body is pumping-in an extra £17.8m to support employers in training and retraining more workers.
The CITB Onsite Experience Commission will be inviting contractors to apply for funding over the coming months.
CITB Chief Executive Sarah Beale said: “This major investment will build on the success of the Construction Skills Fund and represents an historic investment in training a site-ready workforce for construction employers across England, Scotland and Wales.
“Onsite Experience comes at a critical time for construction when it will need to grow more of its own workforce.
“We face the perfect storm of an uncertain post-Brexit migration system, and an ageing workforce with many set to retire in the near future.
“It is therefore essential that the industry attracts, trains, and retains new talent wherever it can be found to ensure construction isn’t hampered by a shortage of site-ready workers.”
Over the next three years 20 new hubs will be established on construction sites across England, Scotland and Wales.
Hubs will be tailored to provide training in trades where particular shortages have been identified and connecting new talent with educators and employers.
Each hub will develop links between employers, colleges and local government to meet locally identified skills needs.
Many of the hubs will be in rural and “left behind” areas that have also not benefitted from the earlier and complementary Construction Skills Fund (CSF).
Beale added: ” I am confident that by making its largest ever investment in the Onsite Experience Commission, CITB can provide the construction industry with the modern workforce it needs to become more inclusive, more sustainable, and construct a better Britain.”