replacing tile at fireplace
#1
We are replacing the tile in front of our fireplace. The area is 5 ft. x 1.5 ft., a small area. We've removed the tile, but need to know how to prep the area to be retiled. The mortar under the original tile has the impression of the old tile in it. How to we need to remove this, or do we, in order to have a flat surface to retile on? Any other useful hints for first-time tilers!?
#2

If the existing mortar is solid, then get a hand held grinding stone and knock off all of the high spots. Then with the same polymer modified thin set that you will use with the new tile...use the flat side of your trowel to skimcoat the fireplace. When it's dry, use the stone again to smooth out any other high spots...and your ready for tile.