How To Remove And Replace Grout

Several years after a renovation, you may find that the grout from your tile installation is starting to show signs of wear. You may also encounter that the old grout may be moldy and no longer capable of being cleaned. Or, you may decide you would prefer to have different grout color. While you may only need to clean the grout to help maintain a more polished appearance of your tile, removing and replacing the grout may be the best option when damage or wear occurs over time. 

Removing and replacing grout is easier than you think and can be a great DIY project that doesn't require hiring a professional. This article will help guide you through the process step by step.

Before You Begin

Before you begin, you will need to decide if you want to remove and replace the grout manually or with power tools. While it is possible to remove it manually, it will take more time and effort. Opting to use power tools will help produce a better result. However, manual grout removal tools do exist and can be purchased online. The instructions below will assume you will be using power tools to complete the job. 

Please note that the new grout will need the proper amount of time to dry, so plan to not use the area for at least three days while it is drying.

What Tools and Materials Will You Need?

There are also a few other items needed when using power tools to remove grout. These include: 

• Safety glasses
• Dust mask
• An oscillating tool with grout removal blade
• Shop vacuum
• Carbide tip grout removal tool
• Utility knife
• Buckets
• Margin trowel
• Grout float
• Grout sponge
• Soft cloths

Materials:

• Powdered or premixed grout
• Grout haze remover (optional)

Using Power Tools to Remove Grout 

The area and the size of the room will determine which tools you should use when removing grout. The first option for a larger, more complex job is to add an accessory tool to a reciprocating saw designed to remove grout. You can also use an oscillating multi-tool with a grout removal blade that can also be used for larger jobs.  

If you are only replacing a small section of grout using an oscillating tool like a Dremel, it can be easier to use as it gives you more control. You will need to use a flat head screwdriver or small chisel to remove grout that does not come off while using either power tool for a clean finish.   

Process to Remove the Grout

It's crucial to protect your eyes, so be sure and wear safety goggles during the entire removal process! Also, you don't need to remove all the grout. Focus on removing all of the dirty grout on the surface. This will give the new grout something to bond to. We broke down the process to remove the grout, below: 

Step 1:

While holding the power tool horizontally to the grout line, slowly lower and press the blade into the grout. Be sure to let the tool do the work and press down lightly. (Pressing too hard can cause damage to the tiles adjacent to the grout.)

Step 2:

Once you have finished grinding the grout line horizontally, you will need to slightly angle the tool to remove the remaining grout. 

Step 3:

Use your chisel or flathead to remove any bits that did not come off when using the power tool. You may find a utility knife with a dull blade is needed for an even cleaner finish, so keep one handy as you complete the job. The dull blade is essential due to the hardness of the grout and the potential hazard of breaking off the tip of a sharp blade.

It is best to vacuum as you go and keep the vacuum hose nearby to remove grout and dust created during the removal process. Be sure and clean deep into the grout line, so the area is prepared for grout replacement. 

If there is any mold or mildew in the grout, make sure it is completely removed before you start regrouting, or it will just reoccur. We recommend using a bleach solution to clean and erase mold and mildew in joints after using the grout saw. 

Replacing Grout

Now that you have removed all the old, grimy grout, it's time to replace it! Before you start, you should read over the manufacturer's instructions carefully. 

Mix the Grout

Grout comes in two different forms: a dry powder or a premixed tub as a semi-liquid paste. 

When using the powdered grout, you will need to mix it with water in a small bucket, using a margin trowel. We recommend you start by adding 1/2 of the recommended amount of water in a plastic bucket with 1/2 of the recommended amount of dry grout powder. Mix thoroughly, then gradually add more water and more grout powder until you have enough to cover around 3 to 4 feet square.

The mixture should be a smooth, paste-like consistency that is just barely pourable. ​Some grout may need to sit for a short period before applying. See the manufacturer's instructions regarding this. 

Fill the Grout Joints

Using your rubber grout float, scoop up some grout and smear it onto the tile surface. Hold the float at a 60-degree angle, pressing and spreading the grout into the joints. We recommend working in alternating directions to be sure the joints get filled. You can either gather excess grout and move it to the next tile area or reload the grout as needed. Repeat the process until all of the joints are filled.

Some tips when filling the grout joints:

• Move the float diagonal to the joint lines to ensure an even fill.
• Does your tile have rounded or beveled edges? If so, the joints may need to be tooled (the process of removing the upper layer of grout). There are special tools available for this. You can also use the round eraser on a pencil to drag along the joint lines of the grout when it is semi-dried.

Sponge the Joints and Tiles

This is a slow process. Using a damp (not soaked) sponge, remove excess grout once the lines are filled. (Too much water will pull grout out of the seams.) Lightly stroke the sponge across the tile surface without pressing too hard and moving at a diagonal to the joints.  

Continue to clean out your sponge and move it across the tile surface until all excess grout is gone. Rinse the sponge frequently in the water, and change the water as it becomes dirty.

Remove the Grout Haze

Once the grout has completely dried (or as stated in instructions), you will notice a faint haze on the surface of the tiles. Use a soft cloth to buff and remove the haze from the surfaces of the tile, or you can use a purchased haze-removing product to polish the tiles. 

You should seal the powdered form of grout for stain resistance (after the grout has fully cured). Premixed grout usually doesn't need to be sealed. 

In Conclusion 

Even the best grout jobs will start to age eventually. When that day comes, remove and replace it to maintain the tiles’  integrity and beauty, and make the surface sparkle again. 

By using the above tips, you can add new life to your tile job and enjoy your home for many more years to come.