On 15/05/2020 07:29, John wrote:
Ordered and received a 175cm x 125cm (drop) black 2.5cm slat blind to fit
a front window recess. All geared up and ready to fit in an hour. Drilled
5 holes through the sophit at the top of the recess, but some felt as
though there was no hard plaster behind. Tried several positions and some
of the better ones fell inline with the mechanism inside the blind, so no
good. After much up and down on my 3 step stool, I decided to use an
existing hard wood battern, previously used for curtains. I was then able
to fit the blind very securely, but 7.5cm short of full closure.

Much to be said for fitting a batten in the right place first. Something
I do regularly in my old house with rubble stone walls and lath and
plaster internal walls (with studwork all over the place).