Help with whether to lime plaster or just plaster

[Chren]

I’ve started renovating a Victorian property in central Cambridge.

Behind where the skirting board was is just brick wall and in places the plaster crumbled a fair bit (ref photos).

I need to move into the house in 2.5 weeks and want to move the project along without injuring my arm any further (I rebuilt an entire lath and plaster wall).

My question: should I still use haired lime mortar etc on the outer walls where the old plaster has failed (and leave the inside walls to the plasterer to finish off) or would the repairs with regular plaster not matter on what is essentially a smaller surface?

 

[Cubist]

Assuming you mean if you use a gypsum plaster rather than lime then the issue is that you may not get a clean and solid bond between the old and new plasters and you may see some separation/cracking at the joint line.

 

[larry]

The lower bit of the wall is where the breathability and water tolerance is likely to matter most especially if you don't have a DPC. Looks pretty chuky, though. There are plenty of products you could use. I've had success (as DIY only) with a thicker NHL base coat (NHL mixed with plastering sand) and breathaplasta thin on top.