Michael Lockwood told a public meeting on Wednesday that the charred building, in North Kensington in London, would be covered in August.
He said that he expected the demolition of the tower block, where at least 80 people died in the fire on 14 June, would begin "towards the end of 2018".
He added that some possessions could be retrieved from 33 of the block's flats.
Speaking at the Notting Hill Methodist Church, Mr Lockwood said the recovery operation tower block could last until November this year.