Garage render

[BeckyEdinburgh]

Hi
I have an outside garage that has been rendered but the top layer has blown.

Can I replace the top layer only or do I have to take back to brick?

Thanks

 

[ree]

OP,
Take it back to brick.
Scarify the first coat & allow first coat to dry for 24 - 48hrs.
The new render should finish with a plastic Bellcast about 150mm above ground level.
Use plastic angle beads.
FWIW: your gutter is a bit wonky?

 

[BeckyEdinburgh]

Thanks hadn’t noticed the guttering just moved in lots to tackle