I am looking at using bricks as the base for a new hearth which I intend to tile on to with large floor tiles. As the picture shows, the level of the opening is slightly lower (approx 1cm) to the height of the bricks (will be >1cm once brick mortar applied to secure them to concrete floor). I was wondering whether i need to use SLC to level the opening to the same level as the bricks or whether I could get away with just using a bit more tile adhesive? Also, there is a gap between the bricks and the lip of the opening. Will this need filling first? Or could I just tile over the gap once level? This is purely a decorative hearth - not for a burner/fire. Thanks in advance