Only hire contractors who can provide you with images of previous work they've accomplished. Metal roofing is a difficult project for two reasons: waterproofing and symmetry. You want to make sure that your contractor is capable of installing roofs that are strong and durable. Pictures are a great way to get a general idea of how skilled the contractor is.

The contractor should be willing to offer you an estimate. He or she should also be willing to put the estimate in writing for you. It is likely that the estimate will have a disclaimer on it stating that the estimate could change over time. This is normal and you should be fine with this. If a contractor is not willing to put the estimate in writing, then he or she may not be the contractor for you.

Don't hire a contractor who expects you to pay a deposit of more than 25 per cent before work begins. This 25 per cent is calculated as one quarter of the total estimated cost of the project. There is no reason for you to have to pay more than this to get the contractor moving.