In order to protect your travertine wall tile from damage, you should seal it immediately after you install it. While you could call professionals to handle your tile installation, you can save money when installing and sealing travertine tiled walls by doing it yourself.
Step 1 - Preparing the Wall
If possible, grout the tiles before sealing.
Immediately before sealing the wall, use dish soap, and water, or a specialized stone cleaner to remove any dirt and dust from your travertine wall. Rinse your wall off with distilled water and allow it to dry.
Step 2 - Sealing the Wall
Now that your wall tiles are clean, you can seal them without entrapping any materials that can lead to unattractive wall tiles or a weak, easily damaged seal. Use your brush to apply the sealer according to the manufacturer's instructions.
Step 3 - Adding More Coats
Allow the sealer to dry completely on your travertine tiles. Once you have done this, you may want to add additional coats of sealer. Whether this is a good idea will depend on the particular brand you are using. Consult the instructions, and brush on further layers of sealer if your specific product recommends you do so.