I had a damp proof system installed several years ago and it has failed. The guarantee has exlcusions and the contractor is very being less than forthcoming. If you have had a similar experience, let me know. People are taken in by guarantees and give up - guarantees are not the "be -all -and -end all"...you have legal rights. For example, a guarantee cannot exclude your rights at common law or under Statute..you may be able to claim foreseeable losses eg redecoration, which is usually the expensive part and is usually excluded by a guarantee...don't be fobbed off.