Hi.  We are looking at a large project involving removal of stains and cleaning up glazed brick walls in an old school.  I am pretty sure some of the yellowing is from old wax.  Not sure what some of the other stains are.  We are doing a test late next week.  Some areas of grout are deteriorating due to water damage, it appears, from the outside wall migrating in.  Don't think the  custormer is looking for perfection, just a better, cleaner look.  Was wondering if anyone has experience as to efficient methodology - equipment, chemicals, techniques etc.

This is one of those jobs that is probably open ended enough that I would probably want to bid time and materials.  The whole building is 48,000 sf and includes 3 stories of hallways and a large gym.

I attached some photos below.  Thanks.
Baird