Watch the video report by ITV Meridian's Penny Silvester:
A retired school teacher from Reading, who was almost conned out of £30,000, is warning others to be on their guard against rogue traders.
Ann Dismukes raised concerns when a £40 quote for clearing the gutter escalated to work on the whole roof.
She raised concerns with Trading Standards after becoming ill as a result of worrying how she was going to pay.
The traders, calling themselves The Roofing Firm, have been convicted for the attempted scam.
The work has now been done properly by professional builders at a third of the cost.
Ann Dismukes was in her garden feeding the birds when a man came up to her and asked if she would like the gutters of her house cleaned.
Ann says she thought she was helping someone to get work, so agreed for it to be done for £40.
But, within days, scaffolding had been put up and tiles were taken off the roof, as the workmen piled on the pressure and insisted the whole roof needed replacing.
Ann Dismukes says she had loads of "horrible days" and sleepless nights worrying about how she was going to be left.
She said: "I hadn't got that sort of money. I wondered where on earth it was going to come from."
Ann Dismukes, Home owner:
Ann's son, Steve Dismukes, had become suspicious at the roofing firm's reluctance to put anything properly in writing.
He called in Trading Standards and this week, the rogue traders were successfully prosecuted.
Steve says he was "outraged" when he found out people were trying to trick his Mother.
He says: "The fact that anyone could meet her and try to rob her of such vast sums of money, and leave her with a roof not fit for purpose...I just can't understand how a person could do that."
Steve Dismukes, Son:
They spent a week talking to my Mum. She likes to be friends with everyone and is the sweetest person.
Matthew Golledge from Reading Trading Standards says in some incidents with rogue traders, it's often the elderly and vulnerable who are victimised and lose their life savings.
He says: "This prosecution sends out a clear message that the council will not hesitate to act against these offenders who carry out illegal activities."
Matthew Golledge, Reading Trading Standards: