Sealer Guide: 500ml covers 1Sqm 1l covers 2-3 Sqm 2l covers 3-5 Sqm 5l covers 10-20 Sqm Pattern tiles: Are pre-sealed in the workshop. Pattern tiles need to be sealed after installation as well. Clear concrete: Tiles are not pre-sealed in the workshop - therefore it is not mandatory to buy our sealer for the clear concrete collection All tiles: We recommend applying 2-4 sealing layers on the tiles (pre-seal of pattern tiles included), depending on the traffic/use of tiles. Please contact us on email@example.com for any questions on above. Please read through our installation and maintenance guide for any uncertainties.