We have, for a considerable amount of time, been prepared to believe the claims of product manufacturers. I’m a dentist and this toothpaste makes your gums stronger and your teeth whiter (because it contains an advanced anti bacterial system with added whitening molecules). Anyone older than 40 will remember the anti travel sickness strips people used to fit to the rear of their cars.
The Dutch philosopher Baruch Spinoza, a contemporary of René Descartes thought (unlike Descartes) that the very act of understanding information was believing it. Finding evidence to the contrary would enable a ‘mind change’, but until that time we believe everything. Whether or not we like the idea, the success of advertising techniques and more recent experimentation indicate Spinoza was correct. Add into this equation a seemingly quick easy fix for a problem and you are onto a commercial winner. This has been around for along time. ‘Mundus vult decipi, ergo decipiator’, attributed to Petronius, a kind of first century roman Oscar Wilde, literally translates as ‘The world wants to be deceived, so deceive it’.
It would be unfair to suggest the various ‘urban building myths’ (such as what wood borers and wood decay fungi can actually do) were somehow initiated by those companies that would ultimately profit from them. It would be fair to say those companies have no commercial interest in a considered scientific approach and actively propagate the myths. They often affect draconian and specious treatments, using the vehicle of a guarantee that their (predominantly) unnecessary work will be effective. The ‘remedial guarantee’ is a marketing tool, which proved so commercially appealing (allowing building owners, insurers and lenders to ‘pass the parcel’ with liability) that it became endemic in the building industry.
It goes without saying a builder has to ensure the quality of his work or a professional indemnify his advice, but a point had been reached where some mortgagers would only lend against a 400 year old timber framed property on condition the timbers were sprayed or injected with biocide, or lend against a rubble walled vernacular building on condition the walls were injected with a damp proof course. Thankfully this is now changing, with some national building insurers such as the NHBC changing their policies to reflect the realities of existing and historic buildings.