I need to tile an L-shaped section which is currently a rounded wall corner (corner faces towards you - external?). My plan is to square the corner, then tile in two square sections. The round corner is probably a 150mm radius curve. I was thinking of a section of angle iron at 90 degrees, secured into the plaster/ brickwork which would be then either tiled directly or covered with board, then tiled. Or a series of corner brackets spaced, then connected with board. The idea is to match the 90 degrees with the existing walls, not to just add plasterboard to it. Any advice? I cannot seem to imagine the best way to achieve a strong finish suitable for tiling. Thanks.