I've read many of the responses to this post and what is absent in the conversation is working with the facilities engineer at this charter school.  This facilities engineer should know the building and appropriate code.  Discuss your proposal with this person and possibly obtain a Hot Work Permit.  While  hot work permits are generally used for welding and related activities I think it is worthwhile in this case.  This facility engineer would also be the person most likely to contact the local fire department for suggestions and fire extinguisher training.