1. Are you licensed? (County Required) Make sure they have this document for the county you live in, many companies will show you their occupational license only, do not accept only that.

2. Do you carry Workers' Compensation and Liability Insurance on all your employees? This will be found on a document called liability of Insurance. Liability will protect the property damage but does not protect against a workers injury, you must make sure that every single employees has workers comp. Many will protect property damage but don't protect against injuries to employees.

3. Do you hire Sub Contractors? Many companies use sub-contractors and very often they don't have the proper license or insurance and this can make you liable.

4. Do you have a warranty? A good warranty should be at least 5 years.

5. Do you require a deposit? Most legitimate contractors will not ask for a deposit.