Replacing Welsh Slates - what slates do I have? And are these replacements ok?

[GavIsGone]

Hi

We've got a decommissioned wood stove and we'll soon be having the flue removed, so the hole will need to be patched over...  The same will be needed for a roof window or two we're having removed later in the year.  We are supplying the slates.  Our existing slates are 20" x 12". 

I've been told that ours are likely Penrhyn Heather Blue, and wondered whether you guys agree? 

Also, we went to the reclamation yard at the weekend and picked up some matching slates for the patch up work needed.  I'm guessing it is hard to tell from photos, but I wondered whether anyone can tell what condition they are in?  I read that they are supposed to ring when tapped; these certainly don't.  But then I also read that not all old tiles will ring. I could try a short video of me tapping them with a hammer and post it to Google Drive?

Are the size of the holes and the damage around the holes a problem?

The reclaimed ones are also a tad larger; just by a few mm. Will that make the roofer's job more difficult or is that quite normal and expected?

Any thoughts before the workman comes to fit them would be much appreciated.

Many thanks

PS - I've uploaded the photos to Google Drive as there are quite a few of them.  Hope that's ok.  I'm happy to upload them into the thread via the forum if that's preferred?  Just let me know.  Cheers. 

Slates on house:
https://drive.google.com/drive/folders/1YpUPrAZ6QQ35g5d1BtWdEUwxTb9iPOi8?usp=sharing

Reclaimed slates bought:
https://drive.google.com/drive/folders/1byJSHXGQ35OGeQbRsBeFQwSI6b3gIDc1?usp=sharing

[stinga]

G'day,


I guess....

>Are the size of the holes and the damage around the holes a problem?
They should be able to re-hole further in, so should be a non-issue.

>The reclaimed ones are also a tad larger; just by a few mm. Will that make the roofer's job more difficult or is that quite normal and expected?
They should be able to trim them down.

>I read that they are supposed to ring when tapped; these certainly don't.
If they go 'dunk' it maybe they are cracked, some sore of sound when a plate is cracked.
Ours never ringed but didn't go dunk either

A lot depends on the roofer, some are cr*p.
We have Delabole, in case there is a difference. Wet lay, scantle, diminishing course.

[Nickel2]

I had to look that one up; I'm electronic not building! 
https://jsroofing.co.uk/wet-lay-cornish-scantle-roofing/

[GavIsGone]

Many thanks for the replies. 

It's actually our stove installer who will be doing the repair. He will be installing the new stove, but whilst here taking down the old flue from another part of the house and doing the patch up. So he's not a roofer / slater, but certainly seemed happy and confident enough to do the job

Having no experience with slate, I'm still not 100% how they should sound /"ring" when tapped. I've got nothing to compare them to so it's hard to tell. I'd guess that they're ok, but can't be sure. I'll see if I can find any relevant youtube videos...  That might help. 

Thanks again

[biff]

 Hi GG,     
         I have a cousin, a retired plasterer who had a very profitable hobby collecting old slates. He became an expert in old slates and used to show me is packs of graded Bangor Blues. He travelled all over collecting and storing his slates  Then he would fill orders for new roofs.
   The only thing I can advise you at this point is to ensure that your plumber/roofer uses a roof ladder and does not  walk about on the roof.  Good luck.
     Biff