Mortar or Expanding foam?

[Caiport85]

Hi,

Im in the process of having some building work done, whilst replace an upstairs window we have noticed that, on both the inner and outer wall, the mortar has come loose and there are a fair amount of gaps. Would it be better to re mortar the brickwork or would expanding foam do the same job?

 

[John D v2.0]

mortar if the bricks are loose, expanding foam if it's not
would be my unqualified opinion