When does this roof need replacing?

[Jazzuit]

It's a house built in the 1970, so the roof must be of original construction. From what I can see, the tiles are plain concrete type (?). After reading numerous websites, the apparent life span of those varies widely, from 25 to 60 plus years. Roofing companies usually give it just 25-30 years, for obvious reasons, other would say it could last over 50 years if looked after properly.
There are no visibly damaged or cracked tiles and no leaks/dampness/outside light visible in the loft.

So the question is, if cleaned of the moss and kept in good condition, will it last for another 10+ years? Any comments appreciated.

Here is the picture of the roof in question:

 

[vinn]

Your tiles and roof structures look to be in great condition. They could be good for another 40 years.
Leave well alone and do not allow anyone any kind of access to your roofs - they will walk on your tiles and leave trails of damage.
The moss doesn't appear to be significant. Keep any local foliage or trees in well trimmed order.

 

[Jazzuit]

Your tiles and roof structures look to be in great condition. They could be good for another 40 years.
Leave well alone and do not allow anyone any kind of access to your roofs - they will walk on your tiles and leave trails of damage.
The moss doesn't appear to be significant. Keep any local foliage or trees in well trimmed order.

Thanks for the reassurance. Do you think it's better to leave the moss alone too? I've read somewhere that it could be harmful for concrete tiles...

 

[Burnerman]

It does no real harm but it retains a lot of moisture......I had to scrape some away from a Velox flashing not so long ago as there was a huge build up.
In fact my own roof produced 4 wheelie bins full two years ago
If you are looking for an anti moss chemical then Bayer Garden do a good one as a trigger spray (B&Q.) Maybe you could reach between the dormers with that.
John

 

[chappers]

Just leave it be

 

[datarebal]

You or others will likely cause more damage de mossing.. Maybe hook the big bits off, no scraping or jet washing.
You could try the copper strip trick between the dormers.. after time it can work......a bit.

Flat roof to dormers will fail before the tiled roof. Yes concrete Plain Tiles