NEC ECC: Change to Works Information / CE

The Client released a core report 3 weeks after contract award. This showed a hard (german) concrete road below the asphalt road but was within the (700 series )mill 100mm (continuous) rate. They refused a CE as said the rate should cover milling both materials, however we now need to mill the asphalt first , change picks on miller then mill concrete.
As this is not continuous surely it must be a change to the works information / CE. I appreciate this is more of a Highway spec question but any help with this would be great. Cheers.

It is not clear from your question if the “core report” has been issued as revised Works Information, ie the previous WI showed a different pavement section, or if the report was issued as revised Site Information or just for information.

If it was the first, a change in WI, then you should notify the matter as a compensation event. If it is one of the others then, assuming it is an Option B contract, you should check the Method of Measure to see if the BoQ is required to differentiate between different materials to be milled. I suspect it doesn’t but if it does then raise a compensation event for an error in the BoQ (60.6).

Failing either of the above, I would suggest that you raise a compensation event under 60.1 (12) for physical conditions. You will have to justify that the hard material was not foreseeable based on the information available at time of tender – see clause 60.2.

Hope that helps.