An alternate or additional test is for a dye to be put into the roof gutters with a view to testing whether it can find its way into the sewers. Rainwater downpipes connected to the sewerage system are one of many defects that may exist in a building. There may be structural defects. Subsidence may be another problem. Readers will be aware of cases in which extensions or alterations have been made to a building without the consent of the requisite authorities.
Flooding can be a problem.
There can be defects in the electrical connections, the gas connections, or the water connections. There may be termite or borer infestation. Another issue is the value of a smoke test report. The cost is not insignificant. Obviously, a purchaser will have a remedy if the report is wrong but the position of a subsequent purchaser from the purchaser who obtained the report, when the subsequent purchaser seeks to rely on the report, is not clear.