Gypsum or Lime

[Ahad]

We are in the process of renovating an 1820s townhouse. 
 

Having a nightmare trying to line up a lime plasterer. Front elevation is double skin brick without a cavity, facing pretty much due South.  
 

What would be the consequences of going down the gypsum route for the internal plaster? We’ve managed to safe the original lime on almost all of the other external walls. 

[nod]

If the original lime is skimmed with putty lime It will look exactly the same as gypsum 

[Ahad]

Our builder seems convinced that we’d end up with damp and problems down the line….

[Mr Punter]

If the brickwork is getting saturated you could treat it externally with a coat of StormDry.