A question for roofers: Aluminium nails on slate roof?

[phil63]

My partner had a roofing job done on a joint freehold flat in 2016; a late victorian mid-terrace in London, to replace the original slate.
At the time, they were using aluminium nails, although the spec. asked for copper.
A few years down the line, and a tile has detached and is sitting in the gutter. I haven't been able yet to find what caused the problem, whether the tile failed or the nails.

The original 'roofer' who did this work is not proving very good at returning calls, or talking about fixing the problem.
A question for roofers then: Are aluminium nails a no-no on slate roofs for a decent lifespan? What redress do we have on work done four years ago, if it turns out to be aluminium nails failing, and the spec. calls for copper?
Thanks in advance.

 

[datarebal]

They have a decent life span.
The problem is likely to be a failed slate.
Having said that , copper is best, as are stainless steel.
Which ever fixing was used the slate may have still failed. Post a picture of the slate in the gutter

 

[phil63]

Thanks for replying Datarebel; I was actually there today, and took some snaps.. The slate in the gutter is intact, and I can see the two fixing holes which don't particularly look 'blown out' or oversize; difficult to tell. What also worries me is there is obviously mastic or adhesive on the tile; I don't think this was in the spec?! I'd be interested in your opinion on the slate quality, as it looks all over the place to me, and zooming in as I have done you suddenly notice a lot of overlapping edges where the slate should be butting, and some very large gaps.
I'm so worried about this, I'm going to take a ladder over tomorrow and have a closer look; I'll try and see if there is sealant under every slate, or whether that was a one off effort to try and fix the single one - which obviously failed anyway.
I'd be interested if there is anything else you think I should be looking for while I'm up there.

 

[datarebal]

Looks like they have stuck it back with mastic of some sort as you say.
I'd guess one got damaged so they replaced it in this shoddy manner.
I still don't think you need worry about the actual nails. They won't have failed. Not the neatest bit of slate work, looks to be a low grade slate by the rusting pyrites.

 

[catlad]

Not worth using copper nails on those slates!

 

[phil63]

Catlad do you think the slate quality is that bad? The original spec. was to re-use any useable old slate on the front elevation, and use entirely new reconstituted slate on the rear elavations, which no one can see anyway. Next thing he apparently turns up and does the job entirely in this grade B slate, suggesting he's doing them a favour...

 

[catlad]

Well obviously I didn't see the original slates but I wouldn't be surprised if they outlasted what you have now.

 

[datarebal]

Probably sold them on

 

[catlad]

Almost certainly...