A 37-year-old drug user set fire to his family home in Pichit after an argument with his mother about money, and the blaze burnt down an entire block of houses on Sunday.
The fire was first reported about 9.50am in Khao Sai market in Thap Khlo district.
By the fire was put out, it had destroyed a block of 10 houses.
On Monday, firemen remained on watch to ensure the fire did not rekindle among the ashes. Total damage was estimated at 50 million baht.
The fire began in a home owned by a woman identified as Ms Wanna that also operates as an outlet for cooking gas.
Police believed her grown son, Yutthana, had deliberately started the fire.
Mr Yutthana had an argument with his mother about money. He was left angry afterwards and went to his room, where he started the fire.
He was charged with arson with intent to destroy property, which is a serious offence carrying the death penalty.
The suspect was also found in possession of methamphetamine and a gun.
