old or new slates?

Following advice from this group
I'm looking at getting a professional roofer to felt and reslate my roof.

There's a posh side which is visible from the road,
and hidden bits which aren't.

My first thought was to use the old slates on the posh side,
and new ones on the hidden bits of roof.

But if the old slates are from different bits of the roof,
some from north facing, some from south facing,
won't they be weathered different,
and thus the posh side would have a splotchy chequerboard look.

So would I be better getting them to put new slates on the posh side,
so all the slates look the same,
and will weather together?


--

[george]

~ [g] ~
~ george at dicenews dot com ~