On Jul 19, 2:03*pm, Jim wrote:

Is there any area of open vertical space next to the stairs? A picture
would be useful.

The stairs come down one side of a room, so they are open into that
room below first floor level.

How about arranging a temporary wall anchor using a piece of wood and
some wall fixings or are you trying to avoid damaging plaster? Then you
could use ratchet straps to take the load.

That's a good idea. It might be possible to find such a point on the
landing. I'm not too bothered about the plaster as it's easily
patched.

Cheers
Richard