How to Replace Moldy Grout
When grout becomes discolored, cracked and chipped, it's time to replace it. Follow these step-by-step instructions to learn how.
Sick of Moldy Grout?
Here's what you need to fix it: 1. Grout saw 2. Vacuum or soft brush 3. Abrasive cleaner 4. Rags 5. Grout (non-sanded for joints smaller than 1/8-inch, sanded for 1/8 or bigger) 6. Float 7. Citrus-based cleaner 8 Grout Sealer
Saw Out the Mold
Working in one 2-by-2-foot area at a time, run the saw up and down the grout line.
Vacuum Loose Residue
Vacuum out flaked residue, or use a soft brush to remove the grout pieces.
Clean Grout Joints
Put some abrasive cleaner on a wet rag and rub the joint to remove any remaining residue.
Mix the Grout
Lay the Grout
Clean the Tiles
Add a Skim Coat
Add a “skim coat” after the first application has dried. This will fill in any tiny holes.
Clean Dry Grout
Apply Grout Sealer
Follow the manufacturer’s instructions for applying grout sealer. If you follow the directions, you should never have discolored grout again.

Photo By: Lee Rogers / iStock
Photo By: John Loo via Flickr Creative Commons 2.0