On 19 Jun, 20:00, " wrote:
I've got a large North-facing house wall of soft Norfolk red bricks -
and a large number have spalled.

It's really an impractically large number to cut out and replace.

I've been trying to patch over them with lime mortar (lime putty,
sharp sand and red brick dust).

Mix is good consistency & sticky - but it still isn't bonding very
well to the bricks (which have been gone over roughly with a wire
brush, brushed down and then wetted).

So I'm thinking - maybe wet down with 10% pva solution?

Other suggestions?

Dear Dom
Without question the best repair will be the lime - which is in effect
a lime render shaped to look like bricks. However, if you wish to
reconsitute the bricks then one way of doing this that I have done
sucessfully with a 20 year (so far) no-problem success rate is to:
key the brick and remove all friable material (you don't want
expanding salts contaminating the substrate
if it needs it screw in some stainless steel eml with stainless screws
apply SBR and put in a light coloured sand /brick dust/ cement mortar
(you will have to get lots of damaged old bricks)with sbr in the mix
and when set but not hard cut out the pointing area later to be
pointed
once set point in gaps

Chris