"Bogus traders" and "cowboy builders" are operating in flood-affected areas, the government has warned.
The Department for Communities and Local Government (DLCG) said that fraudsters were offering a range of services in areas where reconstruction work is ongoing.
A spokesperson said: "Fraudsters are offering a range of work from construction, tree-chopping, garden clearance and roof cleaning. Clearly substandard work may be dangerous and will only add to the misery of local people and bring additional costs."
Discussions are also being held with the construction and insurance industry to ensure that only reputable builders took part in the rehabilitation effort.
Communities secretary Hazel Blears said: "While the vast majority of people, including the building industry, are responding positively to the challenge it is extremely saddening that some people are trying to cash-in and exploit the hardship of others.
This behaviour is completely deplorable and I would urge residents to be vigilant if they are approached. There are a number of places where people can go for free advice including National Federation of Builders, the Federation of Master Builders or Consumer Direct."
Ms Blears acknowledged that the recovery effort would "take months", adding that work on an aid application to the European Commission to support flood recovery was ongoing.
Advising home owners about how to avoid being duped by fraudsters, National Federation of Builders chief executive Julia Evans said: "Getting detailed estimates in writing from at least three referenced builders is a vital first step to ensuring remedial work is done to a high standard. Alarm bells should start ringing if the work is offered free of VAT.
"People need to ask themselves if they really want the work done by someone who does so little work that they do not reach the VAT threshold, or, if they are dodging their tax liabilities what else will they try to dodge," she added.
Government figures indicate that substandard home improvement work costs £1.5 billion a year. Over 111,000 complaints about cowboy builders were registered with trading standards officers in one year.
A spokesperson for the Association of British Insurers estimated that the costs of repairing the damage caused by the floods were approaching £3 billion.
According to the government, the insurance industry body also recently announced that 45,000 households had made insurance claims in relation to the floods in June and July.
A total of 14,500 claims pertained to damage to commercial properties such as schools, roads and other infrastructure, according to a spokesperson.