My question is, do I need a builder, a renderer or a damp expert? Our Victorian mid-terrace has been extended twice and rendered (not by us). I understand from when we tried to have cavity wall insulation put in that the second 2-storey extension is breezeblock or similar with no cavity. There are hairline cracks in the render. With all the rain, moisture has got in (I'm not sure if through the cracks or some other way) and we now have large patches of blistered paint and plaster inside in the second storey. They don't feel wet / damp. I don't know whether anything's got in on the ground floor as it's a competely tiled bathroom. Thanks.
