How to tarp/ seal flat roof


I have a flat roof that on a garage that is in bad shape. I think the garage is 30 by 50. The plywood is starting to rot away and the main beams are bowed.

I think I’m going to have to build another garage next year but somehow I need to keep the water out from now until then. Any ideas would help. I have attempted to put a tarp on but it really did not work well.

How can I put a tarp on it if it has parapet walls?

There is no wood for me to nail two by fours. There is only concrete from the parapet walls up.


There is no easy way to tarp a flat roof that size. Upload a picture and somebody might have an idea.