Repairing an exposed cavity on an external window reveal

[Flinstone]

Hi all

I would like to seek ideas on how best to proceed with repairing a hole in a window reveal at a friend's semi. The attached photo shows what I mean. I have arrived after the event but it looks to me like it may have been a failing of a previously 'made good' repair when the window was installed many years ago. As you can see the cavity is exposed so presumably something will need to be used to reinforce first before patching over with a cement render?

- any ideas please?

TIA
Flinstone

 

[Wayners]

Expanding mech or fine chicken wire shove in hole.
Sand and cement.
Put uPVC plastic along sill under window. Maybe brown wood effect uPVC

That will hold until you get new window when it can be done properly. Bricked up hole with sill looked at. Maybe soldier bricks along sill.
That's my Idea.