Tiling
#1
#2
Group Moderator
Maybe but it's not best practice. I would remove and install CBU instead (assuming the rest of the structure is sufficient for tile).
#3
Group Moderator
I have installed tile over painted sheetrock/green/blue board when it's been for something light duty like a back splash. If is going to get any abuse I'd feel better removing the blue board and install cement board or Hardie Backer.
#4
Forum Topic Moderator
What kind of wall is it? Tiling over painted drywall usually isn't a big concern if it's a dry location but if it's a tub/shower surround you definitely need to replace the blue board with cement board.
#6
Forum Topic Moderator
It should be fine. Since it's probably painted with latex enamel it would be a good idea to scuff sand it first so the thinset will adhere better.