Two weekends of roof repair for Sergei, a school janitor in Novosibirsk

I'm a school janitor living in Novosibirsk. During the last storm water started coming through the ceiling in 4 places, and the kids' bedroom is no longer usable. A roofer quoted $760, which isn't something I can pay. The good news: a local hardware store has donated the corrugated iron sheets and timber. What I don't have is people to do the work. I'm looking for a small crew who can help over a weekend. Experience helps, but it isn't essential - I'll have a licensed roofer supervising for safety. All you need is to be comfortable with heights or willing to help from the ground. I'll provide lunch, water and lots of thanks. The work will be done on the ground and roof with proper harnesses. If you can only help for a few hours, that's welcome too. Thank you so much.