The work is scheduled to end on December 17, but the contractors warn it could take longer if the weather is bad.
There are three individual phases of work from Catchfrench to Lean Quarry, Cartuther to South Treviddo, and Trerulefoot to Catchfrench.
Each phase will have traffic management systems in place.
Highways England have also announced that from Monday, November 9, the A38 through the Glynn Valley will also be closed to traffic for five weekday nights, for essential repairs.
Peter Heron, spokesperson for Highways England, said: ‘Please be assured we are working with both contractors to minimise the combined impact of these works.’
The A38 resurfacing will be carried out overnight between 7pm-6am and traffic flows will be monitored prior to starting. If these are judged to be too high the start time will be put back.
Quieter
Some temporary lane closures during the day can also be expected.
The Highways Agency says the existing surface has reached the end of its serviceable life and will be replaced with new, low noise material.
The works have been planned to take place at a quieter time of the year and overnight to keep disruption to drivers to an absolute minimum.
Mr Heron added: ‘We are writing to those living immediately adjacent to the works and will provide escorted access to and from properties with direct access onto the A38.
‘We apologise for any inconvenience caused to the local communities by these essential maintenance works.’
The hotline number people can ring should they have any concerns is 0300 123 5000.
Full details on the diversions - see this week’s Cornish Times