Bumpy under lintel

[bureaucrazy]

Tiling around window:.

The tiles are 60X30 10mm porcelain.
The wall tiles will be cut and fit around the shape of the window and then the reveal tiles will go on overlapping with a butt joint. (The tiles are the same colour throughout so will look better than trim I think). So, there will be a 4mm grout line between the wall tiles and the reveal tiles as you look from the front. The edges of the cill/reveal tiles will be visible facing towards you.

The lintel is level but is very bumpy with old adhesive on it. The builder could not get it off and did not want to damage so left it. The roughness is about 6mm deep and it is fairly consistently bumpy all the way along. It is stuck very solid.

I think it could be a problem to tile straight on to it as it is hard to know exactly where to cut the wall tiles and how much adhesive to use to get the 4mm grout joint.

Please advise from your experience what to do here:

A: Tile under the lintel 1st and then cut and fit the wall tiles over it?

B: Skim under the lintel with adhesive to make it flat? (like on the wall above)

C: Use tile adhesive to stick a length of no more ply under the lintel. Leave it to set and tile walls then reveals?

I think with plan C, could the extra weight cause it to fall off? Can it be screwed as well? (not easy to drill concrete lintel)

D: try and remove the old adhesive but it is likely there will be a residue/thin layer left behind which might not be good to stick to.



What do the pros do in this situation?

Thanks

 

[Dave]

Hi , that kooks like a bonding coat snd imho unsuitable to til to as it is. It doesn't look very stable either.
Id be hacking of and D&D sone plasterboard.

Can i ask , why so wide a joint.

 

[bureaucrazy]

Thanks Dave. The photo colours are orangey cos of the lighting but the stuff on the lintel is grey and looks like tile adhesive but I can't be sure what it is. I thought bonding was a pinkybrown colour. It is not as soft as bonding.

You may be right though. it also has wavy grooves running along it. They must have used some sort of toothed trowel when it was applied.

The wavy white lines look like another sort of adhesive (tubbed?) left in the wavy grooves when old tiles were removed. I can't remember what was there before the builder ripped it all out.

I think the best option is to get it removed but there will likely be a thin layer still stuck to the rough concrete surface. Not sure if that can be just primed and tiled on of if as you suggest a board should go over it. Surely that would only add more weight though?

I think the concrete is too hard to drill and screw.

 

[Dave]

Thanks Dave. The photo colours are orangey cos of the lighting but the stuff on the lintel is grey and looks like tile adhesive but I can't be sure what it is. I thought bonding was a pinkybrown colour. It is not as soft as bonding.

You may be right though. it also has wavy grooves running along it. They must have used some sort of toothed trowel when it was applied.

The wavy white lines look like another sort of adhesive (tubbed?) left in the wavy grooves when old tiles were removed. I can't remember what was there before the builder ripped it all out.

I think the best option is to get it removed but there will likely be a thin layer still stuck to the rough concrete surface. Not sure if that can be just primed and tiled on of if as you suggest a board should go over it. Surely that would only add more weight though?

I think the concrete is too hard to drill and screw.

I
Its just the pic makes it look like bonding.
If its not and stuck solid , then simply clean up and tile. You can skim the head in with adhesive.