Advice on the best way to repair please

[shabbaranks]

Hi
As you can see the plaster has completely come away from the wall. Given the recent heat its really hard and brittle to touch and Im wondering what the best way is to repair it?

Im relatively handy and will give anything a go - my feeling is to get some kind of one coat plaster but given its block work behind Im guessing there's nothing for it to key on to?

So any suggestions welcome thanks

 

[Wayners]

Knock it off.
Seal well. Lash on 2 coats of PVA watered down 3 to 1.
Let First coat dry for 2 hours.
Plaster skim over.

One bag of multi finish will do it.

 

[shabbaranks]

Thanks given its a small area would it be worth using Zinsser Gardz as Ive read its really good stuff?

 

[opps]

Thanks given its a small area would it be worth using Zinsser Gardz as Ive read its really good stuff?

The PVA will help to reduce the suction and if the second coat is still tacky, it will help adhesion.

You can buy 1L tins of PVA, alternatively use PVA wood glue if you have some- you might need to dilute that more though.