Mark Kempster, 50, of no fixed abode, was sentenced at Winchester Crown Court on Friday, March 11 after admitting six counts of fraud by false representation at previous hearings.
The court was told that between January 1, 2013 and February 2, 2015, Kempster repeatedly called on a 61-year-old woman in Southampton, after replacing some roof tiles at her home.
He demanded more and more money for the work and obtained from her a total of £15,000.
The court heard that on February 17, 2015, Kempster visited a 90-year-old woman at her home in Andover and persuaded her that her roof needed repair work.
He asked for cash up front and drove her into Andover town centre to go to a bank. He then left when the bank manager became suspicious.
On May 8, 2015, Kempster visited an 82-year-old woman in Alresford and charged her £1,860 for roof repairs that were never completed.
The court also heard that on November 24, 2015, Kempster received £2,650 from an 84-year-old woman in Gosport for work on her roof that was never completed.
A confiscation hearing under the Proceeds of Crime Act will take place on July 18.
Investigating officer Detective Constable Paul Barry said: “Mark Kempster targeted the elderly and the vulnerable and took substantial amounts of money from them.
“This is a despicable type of crime. Throughout the investigation, he showed no remorse to his victims and preyed on their good nature by offering to carry out work on the roofs of their properties.
“This work was often not even required and the work that was completed was to a very poor standard and grossly inflated in price.
“This sentence should serve as a reminder that Hampshire Constabulary will always pursue criminals who commit these types of offences.”