A £250,000 refurbishment project on the fire damaged Kingsdon Inn is due to be completed in time for a grand re-opening on December 9.
Disaster struck at the 300-year-old building in March when Mr Napier lit the wood fire.
"Unknown to me, a spark must have come out of the top of the chimney and set fire to the thatch," he said.
"The first I knew anything was wrong was when someone came in and said the roof was on fire."
Despite the fire brigade arriving within a few minutes, the flames spread rapidly and there was no chance of the roof being saved.
But now the inn is being restored to its former glory and the director of W. Coombes & Sons (Construction) Ltd, Colin Berry is confident everything will be completed on time.
"It is a major project because the whole roof will have to be reconstructed whilst there's a lot to do inside because of the smoke damage and the effects of the water used to put the fire out," he said.
"We've got the advantage that the building has a water proof covering over it, which makes things a bit warm at this time of the year, but will be helpful when the weather turns cooler and wetter," he said.
The work will include the creation of three high letting bedrooms and it will be topped off by a thatched roof.
"There was actually no requirement to replace the thatch because we have photographs from the 19th century showing the building with a tiled roof," he said.
"But it was clear that villagers and our regulars were keen to see the thatch renewed so the owners agreed to do it, even though it involved more expense."