Q: We are often asked about sealing natural products outside. We were told we should seal our product such as Travertine? Below is why we recommend not sealing and the disadvantages of it.
For the sealing, we do not ever recommend it outside for a variety of reasons. Sealers can change the look of the Travertine, and if the wrong type, can ruin it because it traps moisture and then the natural stone is not allowed to breathe as needed. Second, being an outdoor application, the UV rays from the sun have a huge diminishing effect on the effectiveness. So areas will start to weather differently, those in full sun may last 12-18 months whereas areas in the shade may last up to twice as long. Therefore, once you begin sealing the stone, you have to continue doing it. Lastly, we have seen the manufacturers consistently changing their formulas, or going away completely. One of the things about sealers is that you must continue to put down the same type or else it will become an issue. Travertine outside will naturally weather over time, but it is one of the most durable products to take the expansion and contraction in our environment. In the end, unless it is a commercial job with high traffic, we usually just recommend just taking the normal care and then some periodic cleaning. If something like red wine is spilled, hosing it off right away is best, or pouring white wine on it right away (like with carpet) and then hosing it off works well too.