cement or mortar?

[Effy66]

Evening folks... quick question...

Topping our brick wall we have some stone slabs, a few which have come away now due to loose mortar. What do I 'stick' these back with - cement or mortar and is the ready to use mortar any good? Thank you!

 

[Deleted member 267285]

Mortar generally (which is sand and cement). You could use quick setting cement, but sounds like you need mortar as it’s easier to work with. Ready to use stuff I think can be too sandy.

 

[DiyNutJob]

Be sure you don't test the strength of the mortar until many days after. It's an easy beginner mistake to make. You can spray on some water after dry to improve strength.

 

[Effy66]

Thanks.. how should I prep the area underneath the stone slab as just parts of the old mortar have come away leaving a piece of solid mortar in the middle .. can I just patch it up around the existing mortar and hope the slab will 'stick'?

 

[Deleted member 267285]

Might need to seal with a Pva/water mix. Remove any excess old mortar though (edited as had a re-read. Thanks @DiyNutJob!).

 

[DiyNutJob]

You can use hammer and stone chisel to chip away the old mortar. Wear eye protection. Having the existing mortar in place will mess up the alignment of the loose slab relative to the adjacent ones. That or you won't have enough of the new mortar to stick it down.

 

[Effy66]

Thank you all!