I recently moved into an early Victorian cottage which was build in 1852, the walls are rubble filled ashlar constructed from millstone grit and the entire thing has been re-pointed at some point using Portland sand in a ribbon or strap style which all the stone houses in the are seem to have.
As expected I have damp issues with some of the walls, mainly those on the South-Western side of the building, particularly the kitchen wall which, when it rains heavily allows water through the walls, through the travertine tiles and to pool on the worktop and the master bedroom wall which has a damp patch in all weathers and some bubbling (modern) plasterwork.
The first solution which springs to mind is to repoint the problem walls using NHL mortar as the stones on those walls are showing signs of a weakened surface which leads me to my problem:
The stones themselves seem to be stepped, the top of a stone can protrude around an inch of so proud of the bottom of the stone above it (See photos), the ribbon pointing too has bevelled horizontal segments which seem to take the odd stone shape into account (the wall viewed overall is completely vertical), have my walls simply eroded unevenly and the ribbon pointing used as a fix or have the stones been purposely shaped to allow that kind of pointing?
Moreover, how do I repoint these stones with lime without leaving a lip or is that not an issue?
A photo of the house from 1905 (attached) shows no ribbon pointing at all.
I should also note that the ribbon pointing which is visible is typical grey portland cement but once the face has been chiselled from it revealed a darker, almost black mortar which is rock hard and makes it very difficult to find the arisses, behind that though is old lime.
Any ideas please?
As expected I have damp issues with some of the walls, mainly those on the South-Western side of the building, particularly the kitchen wall which, when it rains heavily allows water through the walls, through the travertine tiles and to pool on the worktop and the master bedroom wall which has a damp patch in all weathers and some bubbling (modern) plasterwork.
The first solution which springs to mind is to repoint the problem walls using NHL mortar as the stones on those walls are showing signs of a weakened surface which leads me to my problem:
The stones themselves seem to be stepped, the top of a stone can protrude around an inch of so proud of the bottom of the stone above it (See photos), the ribbon pointing too has bevelled horizontal segments which seem to take the odd stone shape into account (the wall viewed overall is completely vertical), have my walls simply eroded unevenly and the ribbon pointing used as a fix or have the stones been purposely shaped to allow that kind of pointing?
Moreover, how do I repoint these stones with lime without leaving a lip or is that not an issue?
A photo of the house from 1905 (attached) shows no ribbon pointing at all.
I should also note that the ribbon pointing which is visible is typical grey portland cement but once the face has been chiselled from it revealed a darker, almost black mortar which is rock hard and makes it very difficult to find the arisses, behind that though is old lime.
Any ideas please?
