Simplify the job by purchasing a grout removal kit that attaches to a dremel tool.
How to replace old wall tiles grout.
Use a spray bottle and some cold water to wet the areas where you removed the grout.
If the width is 1 8 of an inch or smaller use an unsanded grout.
If the space is larger than 1 8 of an inch use a sanded grout.
Match the caulk at most tile specialty shops you can get or order sanded caulk most floor grouts are sanded that will closely match your existing grout color.
This will remove the grout you freed with the grout saw.
The existing grout color is no longer pleasing to you and you wish to change it.
Clean the damaged grout with white vinegar and water.
Finally wipe away excess water or grout with an old towel or rag.
The old grout might be moldy and beyond cleanable.
Leah demonstrates how to remove damaged grout with a grout saw and then re grout the damaged areas.
Choose the correct type of grout based on the width of your tile joints and where the repair is being done.
Clean joints with a grout saw.
Some areas of grout will be difficult to reach with the multi tool.
Then take an old toothbrush and scrub the seams.
As you do this hold the float at a 45 degree.
Mix one part white vinegar and one part water in a bowl or bucket.
Then dip a clean toothbrush in the mixture and scrub the damaged grout until all the dirt and grime comes off.
This fix is only practical for interior tile floors and when the gaps between the tiles are 1 4 in.
It lets you work up close to the edges without damaging the tiles.
Measure the space between the tiles.
Renewing old grout has always involved long hours of hacking away at old worn grout with a tiny grout saw.
This is where the grout saw comes in handy.
Links to grout tools.
Attach the removal unit and set the bit depth to 1 4 in.
That way you can see the exact color of the grout and buy new grout that matches it.
In many cases it is faster and easier to remove the grout than to clean it.
Care must be taken to avoid damaging the tiles and it is very repetitive the old grout must be removed to a depth of at least 2mm preferably 3mm for re grouting to work properly.
Once you have properly mixed the grout in a bucket apply it with a plastic towel then use a grout float to press the mortar deeply into the joints.
Run the tool guides between the tiles and grind through the old grout.