Pointing on my patio keeps breaking, even after having pointing replaced

It could be the mortar strength, it could also be that the pointing is not pushed down far enough it to the joints. But looking at your question (tiles & pointing keep breaking) I would say you have loose slabs, but if the slabs are breaking then you have very well adhered slabs and there is movement. For slab laying you should always have a good sub base compacted, I always five dot my slabs - this allows any water that may get under to not to touch the slabs as in winter water turns to ice which expands and contracts thus not affecting the slabs. Pointing - I always use a strong semi dry mix brushed in, then I use a jointing iron to really ram the mortar home. If it is really hot, I wet the joints first and then wait for the slabs to dry on top before pointing, then when finished give the whole patio a light misting of water. Hope this is of help.

best option if is wall movement use this https://www.permagard.co.uk/heavy-duty-crack-stitching-kit?gclid=CKjLsvOPz9ECFScz0wodplYAVQ

Sounds like loose slabs disrupting the pointing. In could also be the strength of the mortar and if it’s been done properly.

Try stronger mix with mersey grit in it

.

.

It’s either the mix is off or whoever pointed the job wasn’t pushing hard enough with the trowel. For the mix you always need to add a plasticiser, it’s key. Especially in our climates here in England. It stops the pointing from freezing and therefore cracking.