Cavity wall hole - boarded over

[ZZ1990]

Hi all,

 

Moving a bathroom about - existing soil pipe previously entered the bathroom passing through both external and internal cavity walls at an angle (not a neat 4” hole, more like a 250x400mm hole in both skins). Luckily this isn’t exposed directly to outside as the soil pipe entered a single story uninsulated loft space first. 
 

It’s currently been dabbed straight over with standard 1/2” plasterboard and some rockwool placed in the void in an attempt to prevent draft. 
 

I’ve no idea if this is going to suffice or create problems in the future. It’s not exposed to daylight as such… but there’s a substantial opening through both skins to a loft space. 
 

Could anyone please advise on best course of action (if any) or highlight any issues that may arise? 
 

Many thanks.

[JohnMo]

Maybe a photo of the hole not the ladder would be good.

 

But I would do a proper job - patch the two walls with blocks and cement, after cutting away to make hole to neat shape. Prior to doing the final wall reinstate insulation in the cavity.