R D S wrote:
I've fit (fitted?) a banister to the mother in law's wall.
4 brackets, about 40mm round against wall, three screws in each.

3 went on OK, one is in an area where there is no solid wall.
I glued some plugs in but it's not happening.

At home i'd drill big holes and glue/hammer fat dowels in and screw
into that but I want to contain whatever destruction I cause behind
the bracket

I can't decide what to do that would cause least disruption to the
decor.

Ideas appreciated.

Take the brackets back off and screw a length (equal to ar slightly longer
than the handrail) of 150 x 38mm bevelled edged door lining to the wall with
some long No10 or 12 screws as a backboard.

Finish it to your satisfaction and then screw the handrail brackest onto
that.

NB. If you wish, work out where the brackets will be and put the screws
holding the backboard at those points - and then screw th handrail brackets
over the tops of them.

This is a far neater and stronger method of fixing handrails.

Cash