Sweep the tiles with a broom to remove dirt, hair and debris. Sweep the debris into a dustpan and discard in a trashcan.
Open windows in the room for ventilation, and put on rubber gloves. Mix 1 cup of ammonia with 1 gallon of hot water.
Submerge a clean sponge in the diluted ammonia mixture. Scrub the yellow discoloration with the saturated sponge in a vigorous back-and-forth motion.
Submerge the sponge in the mixture when it becomes dry, and continue scrubbing until you have removed all traces of the discoloration. Continue if yellowing remains.
Saturate a nylon scrubber in the ammonia mixture, and scrub the lingering yellow stains vigorously.
Rinse the VCT floors with a cloth saturated in cool water. Wipe the tiles dry with a towel.
No