you could also consider using concrete screws - pilot hole then impact the screw in. So for example 7.5mm screw needs a 6mm pilot hole
My favourite fixing method into far from perfect walls. Quick and easy to add multiple fixing points which give a nice strong hold.
@Familyman started
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you could also consider using concrete screws - pilot hole then impact the screw in. So for example 7.5mm screw needs a 6mm pilot hole