If you have a leaky roof and have done a bit of Googling or spoken to neighbours, you may have heard about clay roof tiles beginning to "fret".
So, what is tile fretting and what does it mean if you have fretted tiles on your roof?
This is what a fretted roof tile looks like:
As you can see, the tile has started to "fret" or crumble away in the lop left hand corner. This is a gradual process which occurs to some terracotta tiles over decades.
Local sun and moisture conditions, proximity to the sea, quality of materials and other factors can affect how much and how quickly the tiles fret.
Unfortunately, fretted tiles are a bit like ants: there's never just one. If you find a fretted tile, there are bound to be many more nearby.
The worst part of it is, the hole which is letting water in to the roof is entirely invisible from the outside! In the picture above, the fretted part would have been covered by the overlapping tiles above and to the left of it, and there would be no way of telling that the tiles were crumbling away without lifting them all out of their position on the roof.
There is simply no way to tell which tiles may be causing the leaks without removing them all. Even if we were to replace the fretted tiles that could be found, many others will be in a similar state, and will likely leak in the future as they continue to deteriorate.
We are often called out to investigate a roof leak, only to discover that the tiles are fretting away like this. When that happens, we have to deliver the unfortunate news that the only way we can guarantee to make the roof watertight is to replace all the tiles with new ones or with metal deck roofing.
Yes, we could replace the ones we can find and hope for the best. But we are not interested in delivering work we can't stand behind. We would prefer to do it right, and know for sure that the roof is going to last at least another generation.
If you are able to do it, a re-roof is your best bet in the long run. Otherwise you may be repainting your ceilings forever and throwing good money after bad.
In the case of badly fretted tiles, a roof replacement is your only fully guaranteed option. The added value, improved appearance and peace of mind also make it something worth aspiring for.