On 25/08/2015 10:17, Davidm wrote:
On Tue, 25 Aug 2015 09:33:37 +0100, "Brian-Gaff"
wrote:

Have you tapped it to see if its blown, ie hollow sounding and hence no
longer attached to the underlying wall.
It might not be what you want to hear, but I had to have several feet of
this removed and re rendered as nothing was holding it on in some places.
One supposes it was water getting behind it and freezing etc.
Brian
It's not blown - yet, which is why I want to repair it now before the
water gets in and freezes.


Most things aren't fine enough to penetrate a 1mm crack (certainly not
mortar) but the 2 part Profil from Toolstation works pretty well IME