Over the last 10 years, I have seen a dramatic increase in the number of companies offering to seal, coat and paint roof tiles, ridges, hips and valleys. These guys are all over the place because it is a very profitable business, because their mark-up is huge, the material and labor costs are minimal, and they charge more than doing it according to the manufacturers specifications. These companies often have huge marketing budgets and mislead the clients into thinking that they must seal the roof to ‘waterproof’ it.
Lets Dispel a Myth. One sales technique often used by salesmen is that old tiles and ridges will become porous and water will seep through them and into the property.