if tiles are loose then that is a health and safety issue, offer to stick em down one day then clean them another, all in with the price of ccourse, i often stick the odd loose tile down when cleaning commercial, never many so do it for free but make a point of letting them know ive done it. always carry a can off tacifier on the van. if extremely dirty i'd trucmount and bonnet after with dry pad like i always, well at least i think i would, i'd have to see em first. obviously keeping moisture down to a minimum and the dry bonnets and blowers so's not to make the same mistake as the last cleaners.