Stephen O'Kane was part of a wider gang who targeted four vulnerable residents, including in Sunderland and South Shields, by carrying out repair work to gutters, roofs, and fences.
Newcastle Crown Court heard the 38-year-old swindled a total of £175,000 between a period spanning 2019 to 2021.
Prosecutor Joe Hedworth told the court that the offending began in May 2019 when a fictitious company called North East Roofing attended an elderly woman's address in South Shields.
She was told her roof needed to be repaired by a man named Tom and after agreeing she paid out £6,500.
The lady was then contacted numerous times by the defendant in the months that followed for more proposed building work.
In total, the complainant paid £13,850 and had to fork out her life savings to pay for the costs, the court heard.
In January 2020, O'Kane targeted an 89-year-old woman who lived in Gateshead and told her a dead bird was in her gutter.
Mr Hedworth said: "He then informed the complainant the felt was rotting on the front of the house.
"He said it would cost £2,500 to remove the felt and £2,500 to put new felt on."
The court heard she was charged a further £600 to repair flashing on her roof, and another £5,000 for more rotten felt but at this point her son contacted thepolice.
Later in the year, O'Kane committed the biggest fraud against a widower who lived in Penshaw, Sunderland, who returned home one day to find the defendant repairing his chimney and roof.
Mr Hedworth said: "The complainant was happy for the work to be carried out for his own safety.
"The defendant gave the complainant an invoice for £25,000."
However, the man was then invoiced for a further £35,000 which he transferred over, and then another £65,000 which he raised concerns over.
In total, the man was conned out of £126,000 but O'Kane had tried to fleece him out of £149,840, the court heard.
The last victim was an 86-year-old man who lived in Whitley Bay, North Tyneside, who was first offered by O'Kane via leaflet to have his gutter cleaned for £40.
However, when the defendant returned and carried out work on the man's gutter he informed him it would cost £3,500.
Mr Hedworth added: "He returned the following day and said the cost was more than the £3,500 and it was in fact going to be £7,000.
"The complainant said he would not be paying any more than £3,500."
O'Kane, who has eight previous convictions, pleaded guilty to four counts of fraud by false representation and possession of an article for use in fraud.
He also admitted fraudulent use of vehicle registration and driving without insurance or licence in relation to the van that he used.
The court heard that he pleaded guilty on the basis he was not the leading player in the operation, and was carrying out the work to repay a drugs debt.
Mr Recorder McKone told O'Kane, of Borough Road in Middlesbrough, who appeared via video link from custody: "You're still only 38.
"It's clear you are putting your time in prison to good use and you have addressed your heroin addiction you have had for some 20 years.
"You developed a bad drug habit and you had a drug debt.
"You met people from the travelling community who offered to pay the drug debt off if you worked with them."
However, the judge accepted immediate custody was the only option and jailed him for four years and nine months.
David Callan, defending, said his client was living a "miserable" life and wasn't spending the money obtained on an extravagant lifestyle.
The court also heard the majority of the money did not go to O'Kane but instead the group he was working for.