There are several product companies who offer 3 year, 5 year, 10 year and even lifetime guarantees on their sealers. Sounds great, right? Ideally, yes it is great but read the fine print. Most stipulate that the sealer has to be correctly applied (something you can’t verify or contest) and only with the best conditions. This means that the product company can simply argue that you failed to meet one or more criteria and you are out of luck. I’m not saying these sealers are not any good; I’m simply stating that sealers need to be reapplied once every year to 3 years depending on usage. A high traffic area needs to be cleaned and sealed yearly. In a business, you may want to even have it cleaned and sealed every 6 months or quarterly even. Consider this: we do work at a local car dealership and we come in once a quarter to clean and seal their terrazzo. They are constantly having not only people coming and going but moving cars across their floor. On the other hand, I have a customer who has been with me since the beginning. He only has me come in every 2 years to re-polish, clean and seal the travertine, marble and granite in his home. The sealer we use at both locations is meant to last 3 years, with the right conditions, which is about normal. If you do not use, touch, and most importantly spill anything on this stone, there’s no way for the sealer to wear, so yes, the sealer could potentially last forever. For most, we use the areas that have stone.
Back to the point, read the fine print. Understand that just because a sealer comes with a “guarantee” does not mean it’s better than one that doesn’t and vice versa.