If you put a 48 straight edge up against the most sunken areas there s a gap of almost a 1 2.
													
																	Tiling very uneven walls. 
									
	
		
	
																	Preparing an uneven wall surface plastering. 
																	One very big problem that not many people realise if the wall isn t really flat a brick joint pattern will show off every out of plane point in the wall by virtue of sticking out a half tile from the tiles above and below it. 
																	If you don t think you can trowel a coat of mortar to get it even withing about 1 4 the tiles will further even it out when set i would investigate a possibility of mounting a cement board onto the bricks instead. 
																	The problem is that the wall is uneven. 
															
													
									
	
		
	
																	The board will create a perfect backing that will make setting tiles on thinset look like a walk in a park. 
																	This is known as lippage and it can diminish the most professional of. 
																	The mortar is spread. 
																	There is also a spot near the window trim where the wall appears to be built up too much enough so that the tile could end up proud of the trim which i m pretty sure won t look so hot. 
															
													
									
	
		
	
																	If you re tiling over an uneven section of wall the corners of the tiles may stick out slightly from the rest of the tiles. 
																	Plastering a wall can be a super straight forward task but if you have no prior plastering experience it may be worthwhile getting a professional in to help achieving a perfectly flat surface for tiling is essential and this isn t always easy on your first attempt.