An additional loan on a property which already has a mortgage is called a "second mortgage". For example, if you have a house worth $100,000 and the mortgage balance is $20,000. If you need more funds to fund your education or a car purchase; you can get a second mortgage on the same property.
The second mortgages are little difficult to get, especially if your credit is not strong because the lenders who will give you the second mortgage will have second position on the property title.
At MortgageBidder.ca, we can help you find lowest Canadian mortgage rates if you are interested in getting a second mortgage.