There is a small area of render, on the outside of a ground floor timber framed extension of my house, which every year seems to suffer frost damage. This year it was particularly bad, one crack is about
800mm long and 3-5mm wide with a couple of other ones nearby not looking good either.I'm getting fed up of patching it all the time. Obviously water ingress is the root cause here, but I can't find any damp on the inside, all the rainwater goods are in good shape and the roof isn't leaking, either.
What would be a good way to repair this permanently, short of demolishing the extension and rebuilding with bricks ;-) ?