Check for water leaks by checking your water meter. Turn off the water, and note the measurement on the meter. Check back in 30 minutes, and see if the meter reading has changed. If so, you have a leak somewhere. A toilet is your first suspect.
Have you decided that your house deserves a new roof, it's a good idea to start out with the project to investigate the needs of the roof of your house should be able to meet in order to be the optimal solution.