You are in your backyard and a truck with a couple of hard-working-looking men passes by.

The truck stops and one of them tells you – in a worried and concerned way - that they are working on a job in the next block and they have noticed that your roof is developing a problem. He reckons you will have big problems with water leaking through your shingles very soon. “By the way these look (pointing to yours) not sure if you can survive the next storm.”

However, since they are in the area, if you are interested, they could give you a good price for fixing your house. You might accept, thinking that you don’t want to be caught off-guard by the weather.

After shaking hands, they will start working on your house, but they will charge you for things that are not needed, while making a big mess (sometimes sticking spikes in your roof).

In addition to the job you hired they for, they will keep finding more things that need doing, such as painting specific zones or spraying a special compound to stop the surface flaking, etc.

However much you tell them you only want the shingles fixed, they will explain that in order to do that they need to do all these other jobs as well.

How to avoid: never trust people who will just recommend themselves to you as home improvement specialists – always go with your acquaintances’ recommendations. Legitimate contractors give written proposals.

Always hire somebody whose previous work you have seen. And never pay an upfront deposit to workmen you don’t know when they say they need money for the materials first. Proper workmen have credit arrangements in place with building suppliers. The crooks will run away with your money.

There is some key phrases that scam contractors use:
"I just happen to work in this neighborghood"
"This offer is only good for today"
"I can help you finance the project"
"I need cash up front"
"I have materials left over from my last job".