How to replace nib tiles when wall render comes down onto top row?

[stechi]

Hi, Can anyone advise please.

I have a bay window roof on a 1930 semi which has many broken and cracked tiles. The top of the roof meets the upstairs wall which is done with thick hard render which comes down on top of the top row of tiles. So it looks as though I won't be able to lift the tiles to unhook them.

Many of the top row are cracked across and have been repaired with mastic, maybe someone tried to lift some before. It is not actually leaking at the moment.

One end the roof meets the brick wall of the hallway that projects forward, and at the other end it meets the neighbours bay roof which has been re-done with slates.

Is there a clever way to get the tiles out? They are ordinary flat red clay tiles with nib.

 

[vinn]

If you have "many broken and cracked tiles" then it would be best to replace the lot, and insulate, and felt the roof to modern standards.
We dont know, without a photo, what type of bay roof you have or how it abuts at either side.

By snapping a chalk line on the render just above the top tiles you could cut to the line with an angle grinder and free the top tiles.
If you do as I suggested above, and replace all, then think in terms of cutting the render to allow a chase for flashing.

 

[stechi]

Hi Vinn,
Thanks, I don't think it is so many I need to do the whole lot. Yip, I suppose cutting all the way along might be necessary, but not an easy job as this render is really hard.

 

[vinn]

If you find the above too difficult:
Then carefully break up the top course (literally, softly smashing the tiles or snapping with a tile nipper), chip away the render holding the tile course fast, and lift the nibs free - then replace the top course and any other tiles.

Presumably the only flashing you could install would be a fillet of sand and cement to fill any gaps at the render junction.