Some unevenness is to be expected but if your installer did not use a level or the proper setting materials or if someone stepped on the tiles while they were setting up, you may have some serious lippage. This can be dangerous as it is a tripping hazard.  If this is a problem you are facing, there is a solution that does not involve tearing out the affected tiles. First, the floor must be fully ground down to level out the tiles. This can be a bit tricky because if you grind the floor too much, holes start appearing in both the tile and the grout. Sometimes, even if you are careful, holes are created through the grinding process and will have to be filled before sealing. The next step in the lippage removal process is to polish the tile back up. That process is a slow one which will take several steps depending upon how highly polished the customer wants it.  After you have polished it to the desired shine level it’s time to put a penetrating sealer on it. We use Modern Stone Technologies Line of penetrating Sealers.