There are several reasons why vinyl flooring turns yellow. Depending on the reason your flooring has yellowed it can be relatively easy to removing the yellowing--or it can be impossible to clean it like new. The first step is to determine the cause of your floor's yellowing. If your floor has yellowed because of a chemical reaction to the rubber or plastic backing on a carpet or because of a reaction to a long-term contact with any form of rubber, then your chances of removing the stain are almost nil. However, if yellowing is due to a build-up of waxes and/or floor cleaning agents, then your odds of removing the waxy yellow build-up are considerably improved. If you are not certain of the cause of the yellowing, give this simple cleaning method a try before writing off your floors as a total loss.
Mix one cup of lemon juice and 1/2 cup of baking soda. Stir until the baking soda dissolves.
Mop the lemon juice / baking soda solution on your yellowing floor using a sponge mop. Don't be afraid to use a little elbow grease and really work the mixture in. Allow it to dry on the floor for 10 minutes.
Damp mop with plain water to remove the lemon and baking soda from your floor. If the yellowing has lessened but is still fairly uniform on the floor then repeat Step 2. Allow the lemon and baking soda to dry for 10 minutes once again and then mop clean with plain water.
Mix two tablespoons of lemon juice and one tablespoon of baking soda and place on a damp sponge. Scrub any problem areas with the sponge, allowing the lemon and baking soda to dry for 10 minutes.
Damp mop the entire floor to remove any lemon and baking soda. Allow the floor to dry for a minimum of one hour. Fans can be used to speed up the drying time.
Apply a good commercial vinyl floor sealer as per the manufacturer's instructions. Allow it to dry thoroughly, following the manufacturer's instructions before using the floor.
Stubborn yellowing spots may require individual attention with a sponge and the lemon/baking soda mixture. Don't be afraid to really scrub hard.