How to Remove Old Grout from Used Marble Floor Tiles

What You'll Need
Flexible putty knife
Empty spray bottle
Clean rags

A marble floor makes a statement in any home. Installing a marble floor is expensive unless you can recycle old marble tile. You can find these tiles at demolition projects, home renovations and secondhand building supply stores. Using used marble tile to build a marble floor will save you money. One issue with a marble floor made from used tiles is grout left behind when they're removed, and this makes them impossible to install. The article that follows will show you how to remove the grout from the old marble tiles and how to do so in an eco-friendly way.

Step 1 – Soften the Grout

Most grout material is made out of silicone or latex which makes the grout great as a way to waterproof the marble tile. This also means that the grout can be softened by other chemicals. There are many chemicals in the market that are harsh for the environment but there are also plenty of all-natural products too. Acetone is a derivative of alcohol which makes it a great alternative to other cleaners and solvents. Vinegar also possesses many qualities that a solvent does. In a plastic spray bottle combine equal parts water, vinegar and acetone. Spray the grout on the marble tiles with solution and let it sit for several minutes. The older the grout the longer you should let the solution work.

Step 2 – Remove the Grout

Once the grout has had ample time to soak up the solution it is ready to be removed. What the solution does is reconstitute the dried-out grout and dissolves the chemical bond that is formed between the grout and the marble tile. Once the grout is ready to be removed it is important that you are very careful when doing it so you do not damage the tile. Use a plastic putty knife that is firm but flexible so it will not gouge the marble tile. Hold the marble tiles firmly in one hand or braced on a flat surface against a wall or other structure. Put the putty knife on the marble tile at a slight angle and slowly push the blade along the tile so that it digs under the grout. Continue pushing the blade until the grout is removed. Continue in this manner for each marble tile you have and each side that has grout attached to it.

Step 3 – Remove Grout Film

Unfortunately when you remove the grout there will be a film left behind. Depending on the marble tile it may not be that noticeable so take a good look at it. The film will be somewhat off-color and oily to the touch. This oil will make installing the marble floor difficult because the new grout will not adhere to the film. The film will yellow and stain the marble if left alone. Removing the film is easy as all you need to do is dip a rag in acetone and scrub the marble tile.