Obviously there are some big signs that you need to replace your roof. It might have a tree lodged in it! Or it might have sunk completely in a section of the roof, however, there are other more subtle signs that might make you think its time to get that roof replaced.
Tiles Are Peeling / Came Loose:
The first sign that you may need a new roof is a loss of sheen on the tile. Manufactured tiles come with a sheen texture because they serve a couple of key purposes for the tiles themselves. The first is that they help reflect UV rays off of your roof, which in turn cools your home. They also offer an extra layer of fire resistance, which makes them particularly important in dry, arid climates.
The last benefit is simply their aesthetic appeal, although this isn’t as important as the first two. While a moderate amount of sheen loss is normal and nothing to be concerned about, if your tiles are mostly bare, you should seriously consider a roof replacement like Mcdaniel did.
If you noticed that your tiles are curling up around their edges, this is a sign that you need to replace your roof. There are two potential issues with roof tiles that are curling away from your roofing structure. The first is that water will seep underneath the roof tiles and damage the structural integrity of your roof which you can read about here https://www.tor.com/members/singermcdaniel99/ .
The second is that if there is a particularly bad windstorm, it could end up ripping the tiles off of your roof, and if they begin to lift off of your roof, it likely won’t be just a tile or two.
Cracked shingles are an issue for a similar reason as curled tiles. A cracked roof tile will allow moisture into your roof deck, where it can create much more damage as discussed here with common reasons for a roof leak, such as rot or mold. If you notice that you have cracked roof tiles on your roof, they should be replaced as soon as possible, as they are even more likely to cause damage to your structure than curled tiles.
If you ignore a few cracked tiles, you might turn what could have been a simple fix into a major problem.
Moss and Algae
Another issue your roof could face in a cooler climate like Ireland is moss growth. If your roof doesn’t get a lot of sunlight, you may find that moss grows on your roof, especially in between your tiles. This can be an issue because the moss will hold moisture against your roof, which could cause damage either to your roof deck, or to the tiles themselves if it freezes. While moss isn’t quite as pressing of an issue as cracked or curled tiles, it is still worth contacting your roofer about it.