If you're planning on hiring a contractor to do construction, renovation, or repair work on your home, remember that paying "under the table" for a job is not a better deal. If you pay under the table, you probably have no warranty, no recourse for poor workmanship, and you have the added risk of liability if an injury takes place on your property.
Before you hire anyone, be sure to ask a lot of questions, get a written contract, and ask for proof of Workers' Compensation or equivalent private-liability insurance to cover injury as well as any damage that could occur in your home. This will protect you from being liable for an injury in your home, as well as damage to your home and the worker's equipment.
There are many experienced and reliable contractors working in your community--highly skilled professionals who do business the right way.
Information is the key. Know the businesses and individuals with whom you are dealing, and use the information at your disposal, including the information about the underground economy on the Canada Revenue Agency's Web site, to protect yourself!