It is a common problem for holes, voids and cracks to develop in travertine tiles. Filling these holes in travertine will prevent dirt, debris and contaminates from getting stuck in these holes and improve the appearance of the tile floor.
Travertine tiles in their natural state have many holes and voids in them. Travertine is formed from calcite organic compounds. When these organic materials decompose carbon dioxide gasses are formed causing the many holes and voids in the travertine tiles. When travertine tiles are processed at the factory the holes and voids are filled and then the tiles are ground flat and polished. Depending on the quality of the filler and the type of travertine used for the tiles the travertine filler can come out of the travertine causing holes and voids.
Travertine tiles vary a lot depending on the type of travertine used to make the tiles. If the travertine has a lot of voids in the stone then over time new voids can form in the week portions of the travertine. Also polishing travertine can create holes in the week areas of the travertine stone tiles. You can see below the back "natural" state side of a travertine tile that has not been filled or polished.
There are many different types and colors of travertine tiles. The most common type of travertine tile is the lighter colored beige travertine tiles. Darker colored travertine tiles such as the "walnut" colored travertine is also popular in many tile installations.

There are two ways to fill holes in travertine tiles using either an epoxy filler or simply filling the holes with grout. Epoxy fillers for travertine will match the smooth texture of the factory installed travertine filler. Travertine epoxy fillers are generally colored to match the lighter beige colored travertine tiles. For darker walnut colored travertine's you can still use the beige travertine filler but you may want to add a colored tint to the beige colored travertine filler to darken the color of the filler material. Using colored tints to darken the travertine tile filler can take some practice and skill to get the color right and you also will need to know the exact colored tint to match the walnut colored travertine tiles.
To prepare the travertine tile filler you need to follow the manufactures instructions. In general the travertine filler will need to be mixed with a small amount of hardener. The travertine filler will usually set in about 7-10 minutes so you will have to work quickly to fill any holes and voids before the travertine filler sets. If you are filling many holes then you will have to mix multiple batches of travertine filler with the hardener. It is good to have a smooth flat non porous surface for mixing the travertine filler. A spare ceramic tile works well for mixing the epoxy based travertine filler.
To fill the travertine tiles you can use a putty knife for filling the holes with the travertine filler. It can help to tape up the areas around the hole so you are not required to clean up a lot of overflow of the travertine filler from the surface of the tiles. You can then remove the tape and use the putty knife to gently smooth down the travertine filler so it is even with the surface of the travertine tile. You should then carefully clean the surrounding areas of the travertine tile with acetone to remove any excess travertine filler from the surface of the travertine tiles. It is important to remove this excess filler before it has set so you will have to work fast in removing it. You will also not want to disturb the just filled portion of the travertine tile so that the filler retains its flat and even texture.

Another way to fill holes in travertine tiles is to fill them with normal sanded grout. It is necessary to use only sanded grout for filling the holes in travertine tiles. The sand in the grout will give the grout more substance to fill areas of tiles without cracking or breaking apart. The sand in the grout will give the filled area a course texture that does not completely match the smooth texture of the travertine tiles. Still in many cases filling the holes with grout is a simple and easy way to fill the travertine holes without having to use with an epoxy filler.
For filling beige colored travertine tiles a "bone" colored grout works best to match the color of the beige colored travertine tiles. Custom Polyblend's Bone colored grout from home depot works well in these cases. For darker walnut colored travertine tiles a darker colored grout like Custom Polyblends Linen colored grout from home depot works well. Odd colored travertine tiles may require you to use an odd colored grout to match the color of the specific travertine tiles you have. The good thing about travertine tiles is that there are usually many shades and colors throughout every travertine tile so slight shade variations in the filler material will not be noticed.
When using grout to fill holes in travertine tile you should try to mix the grout to a thick consistency with only a small amount of water. You can use a grout float to force the grout into the hole and leave the grout slightly higher than the face of the tiles. Then you can use a grout sponge to gently smooth down the grout so it is even with the tile. You should wring out your grout sponge as much as possible and use as little pressure on the grout as possible. This will ensure that you do not remove too much of the grout in the hole leaving the travertine hole lower than the face of the tiles. It may take a few tries and some practice to use the grout sponge and get the hole filled up even with the face of the travertine tiles.

After you fill the holes in the travertine tile with grout then you should use a terry towel or cheese cloth to remove the grout haze around the surface of the travertine tile hole. You do not want the grout haze to set on the surface of travertine tiles because it can harden up and be extremely difficult to remove later without damaging the surface of the travertine tiles.
When using grout to fill the holes in travertine tiles you should seal the grout 72 hours after applying the grout to the travertine tile holes. The epoxy travertine filler does not have to be sealed but when using grout to fill holes in travertine tiles you will want to seal these areas of grout. Grout will be extremely porous and these filled areas can become extremely dirty and stained over time if they are not properly sealed.
Filling holes in travertine tiles will never give you a 100% factory finish and look to the travertine. If you want the travertine tiles to look perfect after filling them then you will be required to hire a stone restoration pro to restore your travertine tiles. Stone restoration professionals will be able to match the color and look of the travertine filler to exactly match the color of the existing travertine tile filler material. Also a stone restoration company will over fill the holes in the travertine tiles and then use a diamond polishing system to grind down the excess travertine filler giving you a near perfect look to the filled hole. Stone restoration professionals can also take out any scratches and polish your entire travertine tile floor to make the travertine tile installation look like new again.
You can read some valuable information and tips on how to hire a top rated stone restoration contractor at our contractor information page here.