js.b1 wrote:
Plaster thickness is everything re whether this will work.

16mm hard plaster, end-expansion plug, tight hole - whilst the 19mm
screw does not reach the brick it may grip enough for shear and light
pull-out resistance.

3mm hard plaster, 20mm rubbish sand-cement render, MID-expansion
Fischer SX6 30mm plug - whilst a 25mm screw sounds longer, it causes
mid-expansion of the plug and very weak pull-out resistance. I know,
because a test-pull of a radiator fitted thus removed the plugs from
the holes with screws still snugged tight up to the bracket!

And yet you could sit on it and it din't come off....

THINK about it.

UNDERSTAND moment arms shear force tensile force etc etc..