Victorian building damp issue


New Member
The dwelling is on the first floor of a random stone, rubble infill, Victorian building converted to 12 flats in 1970 when lime mortar pointing was replaced with cement and rendered , render since removed.

There is some penetrating damp in external wall.

I have received varied advice from property surveyors.

1) Remove internal plaster and tank.

2) Render the wall.

3) Replace cement pointing with lime based.

4). Treat wall with latest breathable sealant

Would you recommend any of these ?
Any you would disagree with ?

Is it possible to succeed 100% in eliminating damp issues in old buildings ?

All opinions welcome.