While it would be ideal to start a business debt-free, this is not always possible depending on an individual’s financial situation. Starting a roofing business requires some minimum necessary equipment such as a roofing vehicle, ladder rack, ladders, tools, insurance, and other miscellaneous items. A small business loan may be all that is needed to get a successful roofing business started.
In the United States, the Small Business Administration is another good place to start when trying to get a roofing company off the ground. They have information on getting business loans here: https://www.sba.gov/loans-grants .
The US Small Business Administration has three different ways to help: debt financing, surety bonds, and venture capital financing. They do not offer grants.
The state in which you reside should also provide helpful information on getting the funds you need to get started.
If by any chance you live in Texas, you can take a look at Texas business loans on this link.