I've got a fibre slate roof (Marley Eternits) datestamped 1991 on the back of them.
Considering the install was a bit crap (half inch plasterboard nails) they've done ok. Where the short nails have worked loose the rivet hole and nail holes have got a bit big from movement. Refixed with copper nails they're fine, not rattling now.
The top surfaces are getting a bit pitted and discoloured but there's no curling or delamination and it still keeps the rain out.
Think the slates themselves are guaranteed for 30 years so they'll make that easy enough, see what happens as the years go by
Considering the install was a bit crap (half inch plasterboard nails) they've done ok. Where the short nails have worked loose the rivet hole and nail holes have got a bit big from movement. Refixed with copper nails they're fine, not rattling now.
The top surfaces are getting a bit pitted and discoloured but there's no curling or delamination and it still keeps the rain out.
Think the slates themselves are guaranteed for 30 years so they'll make that easy enough, see what happens as the years go by