In Frankenstein, how does the creature try to mend the damage when he burns down the De Lacey's cottage?
Chapter 16, of Mary Shelley's novel Frankenstein, provides the details regarding the burning of the De Lacey's cottage by the creature. To provide a little background, one must first explain why the creature burned the cottage in the first place.
The creature (abandoned by his "father" (Victor), beaten by villagers, and left alone to fend for himself) finds life to be far too cruel. Thinking that he would finally be accepted by another, the creature tried introducing himself to the patriarch of the De Lacey family. The old man, blind, was believed to be the one who would not judge the creature upon his appearance. Unfortunately before he could be protected by the old man, Felix comes home and attacks the creature.
Enraged by the attack, the creature flees the cottage destroying everything in his path. Eventually he returns to the cottage. Finding the cottage abandoned, the creature finally rests (exhausted from his rampage). Later, Felix returns with the owner of the cottage. Felix begins to tell the landlord that his family cannot return given he fears for the life of his father.
Upon hearing this, and the departure of the landlord and Felix, the creature beings to gather materials to burn the cottage. Torching the cottage at night, the creature is sure that "no assistance could save any part of the habitation."
The creature never returns to the cottage.
Therefore, there is no time where the creature tries to mend the damage to the cottage (after setting it ablaze). In fact, he wishes nothing more than the cottage to be burnt to the ground.