So confused over which product for external wall

[Dazls]

1930s Semi, Exterior walls. Previously covered in lime plaster with lime mortar.
Walls now cleaned with some mortar intact and some needs re pointing

.


Wall has a cavity and the outside is exposed brick lower half and then pebble dash top half. Plan to remove pebble dash and render.
Outer face of wall...


Whats the best approach here? Do I need to re point and render inside and out with hydraulic lime and sand mix?

Can I get away with using any gypsum products like hardwall and point with a weaker sand and cement mix?

 

[Retired Spread]

this requires your expertise @John j

 

[tapit]

1930s Semi, Exterior walls. Previously covered in lime plaster with lime mortar.
Walls now cleaned with some mortar intact and some needs re pointing

View attachment 62884.View attachment 62885


Wall has a cavity and the outside is exposed brick lower half and then pebble dash top half. Plan to remove pebble dash and render.
Outer face of wall...
View attachment 62886

Whats the best approach here? Do I need to re point and render inside and out with hydraulic lime and sand mix?

Can I get away with using any gypsum products like hardwall and point with a weaker sand and cement mix?

If the wall has a cavity you can pretty much use whatever you want in and out.

 

[worthwords]

1930s Semi, Exterior walls. Previously covered in lime plaster with lime mortar.
Walls now cleaned with some mortar intact and some needs re pointing

View attachment 62884.View attachment 62885


Wall has a cavity and the outside is exposed brick lower half and then pebble dash top half. Plan to remove pebble dash and render.
Outer face of wall...
View attachment 62886

Whats the best approach here? Do I need to re point and render inside and out with hydraulic lime and sand mix?

Can I get away with using any gypsum products like hardwall and point with a weaker sand and cement mix?

how was the cavity confirmed. i'm a bit confused with the brick - it's a flemish bond in the last picture suggesting the base might be solid wall,
There are a number ot mixed type houses built late 1920-1930s which had cavity ground floor / solid upper floor or vice versa with the top floor rendered. An odd step around the stairwell is sometimes a givaway.

There were also rat trap bond used in 1920s which may have a cavity but should be treated as a solid wall(see pic).

If you are repointing a solid wall then hydraulic lime is not necessarily the best option, particularly as there is so much variability in NHL products marketed as a the same 'strength'.

 

[ChrispyUK]

1930s Semi, Exterior walls. Previously covered in lime plaster with lime mortar.
Walls now cleaned with some mortar intact and some needs re pointing

View attachment 62884.View attachment 62885


Wall has a cavity and the outside is exposed brick lower half and then pebble dash top half. Plan to remove pebble dash and render.
Outer face of wall...
View attachment 62886

Whats the best approach here? Do I need to re point and render inside and out with hydraulic lime and sand mix?

Can I get away with using any gypsum products like hardwall and point with a weaker sand and cement mix?

use insulated Pb. If building control was involved and whole walls hacked off then they would specify an upgrade. You can obviously do what you want though.