Free hosting has nothing to do with professional hosting.
Free hosting is a business model where the customer does not pay for their hosting, you (the host) either pay for this yourself as a loss leader, good intention or by generating revenue from advertising that is displayed either on the customer's site or by requiring people to join communities on your own site where they are exposed to advertising which generates your revenue. With luck you will generate sufficient revenue from these ads to pay your server bill. If not you just close down and give up leaving your customers with no site and they move on to the next person who thinks they can make it work. Not many hosts do make free hosting work, however there are some that mange to keep running.
If you value your site, then I'd suggest paying a few £'s a month for a reasonable quality host.