Cut though wall for patio doors - Tile Advice

[Old_Brown]

I am an experienced DIYer and "finishing off" after a builder!

We cut through the solid stone wall to install patio doors with an existing slate floor in situ The builder has laid DPC and put self level down in the threshold voids created. I have cut out damaged slates and levelled the floor where a hearth was totally removed, also a single slate in the middle of the floor where a newel post used to be (staircase removed). Here the floor is 'nearly' at the right level for tiling cement to be used and pretty flat, i.e. to the level of the original screed. In the patio door threshold, the self-leveller is still about 30mm lower than the top of the existing tiles.

I will cut down 50 400mm square slate tiles to the original 9" x 14" to fit back in the gaps. The originals seem to have been laid in thick-bed mortar on a concrete screed, with the same mortar used as grout!

I have three questions if anyone can advise me!

1. For the floor where the tiles were cut out and I will have the 9x14 to go in - what adhesive to use.

2. Will the grout stain the slate. Should it be sealed BEFORE grouting.

3 How would you raise the patio door threshold level to be ready to tile. Would a mortar mix do the job.

Many thanks!

 

[colski76]

1. A grey single part flexible adhesive
2. Yes they should be sealed before grouting... Then the whole floor (definitely the tiles you're putting back in)perhaps another 2 times after fixing
3. Not sure about that

 

[Time's Ran Out]

Fix the ones in the threshold with sand and cement.
Seal whenever - slate is quite impervious.
Other tiles with fast set flexible adhesive but I'd put a skrim accross the joint first.

 

[Old_Brown]

Fix the ones in the threshold with sand and cement.
Seal whenever - slate is quite impervious.
Other tiles with fast set flexible adhesive but I'd put a skrim accross the joint first.

What would you use for the scrim - would it be like plasterboard scrim, please.

 

[White Room]

Plasterboard scrim would'nt be adequate, if you have enough depth under the tile some expanded metal lathing or some trusted chicken wire....

 

[White Room]

You could also put a strip of ditra across the area where it's been jointed....