It's a double brick wall and the face on some of the "tie" bricks has
spalled. I'd expect this to be less of a problem being the side of the
brick and, anyway, the chances of getting it out almost impossible. What's
the best way to prevent any further spalling? Just face it with some
mortar?

Limewash it. You'd probably want to tint the limewash with some brick
dust

I bought one of these standoffs quite recently, for a similar job:

http://tinyurl.com/4pm6g or
http://www.screwfix.com/app/sfd/cat/...72002&id=32096

It really is the mutt's nuts - I now wouldn't even consider doing any
sort of brickwork from a ladder without one now (which isn't to say a
tower wouldn't be better still). Otherwise where do you put the mortar,
the spare brick or bits thereof, the various tools etc, all without
falling off or dropping things. The wide separation of the feet against
the wall really helps make it more stable too.

Every time I use mine I curse its design. Yes it is great having
widely separated feet and a tabletop to put things on but how about
the four sets of nuts and washers and wingnuts which have to be fixed
in position around ladder and standoff while the ladder is propped up
and over something and the standoff is balanced on top of it cos if
the ladder is laid flat you can't get at the nuts. After the job is
over the standoff cum ladder contraption is too awkwardly bulky to
store so it all has to be taken apart and the nuts and washers and
wingnuts and standoff connected together again cos if I don't then
they will have gone walkabout before I need to use the standoff again

Must have been designed by a man

Sits back and waits for outrage

Anna

~~ Anna Kettle, Suffolk, England
|""""| ~ Lime plaster repairs
/ ^^ \ // Freehand modelling in lime: overmantels, pargeting etc
|____| www.kettlenet.co.uk 01359 230642