[header] How to install ceiling tiles [title] Clean the ceiling. [step] If the ceiling isn't very dirty, simply use a broom covered with a tee-shirt to dust away any dirt. If your ceiling is dirty or greasy, use a sponge to scrub one small section at a time using an all-purpose cleaner. 
It's important to let the ceiling dry thoroughly before applying your tiles. [substeps] A clean surface will make your tiles stick more effectively.