HOW LONG WILL ROOF TILES LAST?
This is in fact two questions: Firstly, 'How long are roof tiles & slates guaranteed for?', and secondly, 'What is the life expectancy of roof tiles & slates'?
Clay roof tiles are, for example, manufactured to BRE standards with a minimum life expectancy of 60 years in normal conditions.
It should be noted however that 'life expectancy' should not be taken as a guarantee or warranty.
Broadly, roof tiles and slates will remain serviceable for many decades - we can supply natural slates with a manufacturer's guarantee of 100 years.
There are a number of factors that affect the length of each manufacturer's guarantee for each roof and the tiles or slates installed: To obtain a full manufacturer's warranty - which varies by manufacturer and product used - the roof will need to be designed by the manufacturer, installed to all the current standards using a complete suite of products and fixings from the manufacturer's own range.
In practical terms, the life expectancy of clay roof tiles will be 60+ years - on occasion customers bring in clay roof tiles or slates to be matched that are much older. We have seen clay roof tiles that are estimated to be at least 250 years old that still had plenty of life left in them.
Concrete tiles degrade over time in both appearance and integrity, and they will certainly be approaching their 'twilight years' after 60 years - having said that we are regularly asked to match concrete roof tiles laid just after the end of WW2 - over 70 years ago - that are still in fair condition.
The life expectancy of natural slates varies according to the type of slate used and the quality, which will as you would expect be reflected in the price, with life expectancies between 30 and 100 years, whilst man made slates have a life expectancy of up to 60 years.
Enviromental factors such as pollution or severe weather (such as in coastal locations) can have a marked effect on roof tiles: when we see old roof tiles from within the M25 boundary surrounding London, it is readily apparent how much worse their condition is than those that we see of a similar age from the Home Counties.
Roof tiles and slates are not designed to be walked on - doing so, when installing solar panels for example, leads to many breakages and leaks.
Pressure washing of roof tiles and slates is arguably the worst thing that can be done to a roof, and it is strongly advised against. If moss is a problem or unsightly, then we recommend the application of a proper Moss & Mould Remover (such as the Cromar Moss & Mould Remover that we supply), and that the instructions are dilligently followed.