Over the last couple of years I've had visits from roof coating companies (the most recent being Thermashield who have insisted that my roof, being 40 years old, is very likely to need replacing if I don't use their services. They have told me that the life expectancy of my roof, when the house was built, was only 25-30 years. I have always looked on this claim with some scepticism, however I was just wondering if there was any truth in the claim. The most recent price I was given was £2000 for a 60 square meter covering.