bath
Sconce mounting 1 - have your contractor install junction boxes for sconces where needed (height, width). 2 - if large heavy sconce you might need blocking/support in wall. 3 - have local mirror person come over to the space to measure for the mirror and make 'knock outs' where junction boxes are located. 4 - mirror gets installed with holes for sconces. 5- electrician comes back over to install sconces.
tiles
Q