We found National Sealing Company online while in search of a solution to correct the slick surface of our travertine pool and lania pavers. Kenny explained the process, even connected us with a local power washing company, which is needed before the seal is applied. The results look great, the sealer makes our travertine tile look fantastic! The surface now has a bumpy feel when walked on with bare feet but so worth it to not have the worry of someone getting injured! Good experience - would recommend!