Hi Sam, All polished porcelain tiles need sealing both before and after installation. You should use a quality polished porcelain sealer like HG. We have this item on the site. Please check for availability. Many thanks, Builder Superstore

Hi Becky, They certainly can be used on walls. As our information states floor tiles can be used on walls however the load bearing wall must be strong enough - often floor tiles are heavier than normal wall tiles. If your adhesive is strong enough then there shouldn't be a problem. Remember though we recommend you use floor tiles on the floor. Thanks for your enquiry.