Hi folks,
I know a question was asked back in September about cell phones on school Wi-Fi networks, but this is a slightly different question and suggestion. As someone who spends a lot of time in school gyms during non-school hours (evenings and weekends), it is usually very difficult to get cell signals in those gyms or hallways near gyms. As has been discussed before, there are many districts that do not allow guest Wi-Fi access at all. This can make things difficult for people running events in your school. 
I wanted to just mention, from the perspective of someone who is often a guest at Vermont schools, that having wifi available to folks who are renting the space on weekends or evenings, would really be doing a wonderful service for those folks. Another option to keep people off of your network could be setting up a repeater or booster to bump up cell service within those concrete block spaces so people can use their phones as hotspots. 
As someone who ran a fencing tournament all day on Saturday in a school gym, there were a number of messages about folks pulling out of the tournament or participant info that we needed to look up and each time we had to walk outside of the building and wave our phones around in order to get a signal do that.
Thanks for considering,
Genevieve/Fencing mom