We had travertine pavers installed when we remodeled our pool. The company that did the install suggested that we leave the travertines unsealed because they get very slick. We did what they suggested for 3 months in the middle of Florida’s rainy season. Algae was a problem from the get go. I used chlorine on them to clear the Algae and noticed some fading in the tiles where it was applied. I power washed but also noticed some of the imperfections of the travertine (porosity) expanded. In addition, the sun was already fading the section exposed to it versus that which was undercover. I had already spent a solid amount to have this product installed and had to find a way to protect it. I searched and found National Sealing, which had a 3 part non slip coating application. The deck turned out awesome. The look of the travertines is enhanced and non slip as they said it would. Easy to work with and accommodating. They are more expensive than the locals, but you get what you pay for and I figured it’s a wash when considering this lasts 3X longer and protects against fading. I have seen unsealed Travertines after they were installed 3 years ago in the neighborhood, they are significantly faded and look bad. Other neighbors just had them sealed, and it’s like walking on ice. Very dangerous. Get it done right and call these guys.