I have used resources in this thread to investigate cracks, and have another recommendation to add.    Robert Walton-Sharp visited the property, carried out a full survey, made recommendations. It was extremely helpful.    He is a structural engineer, so better versed in the specifics of this than a building surveyor, and his prices were reasonable - the lower end of the quotes I got from structural engineers (and the same as some building surveyors). Worth mentioning that some of the building surveyors I spoke to referred me on to structural engineers.      Robert Walton-Sharp  BSc(Hons) CEng MIStructE  SHARP  Structural Design Ltd ? Chartered Structural Engineers  07973 253 164  020 8764 2602    I also had a bad experience with one of the contractors mentioned in this thread, and would be happy to provide info over DM.