Interlocking slates - Sandtoft or Redland or other?

[underclassy]

Hello,
Removing the original slate roof from an Edwardian end of terrace. Nail rot, blown ridges, no felt and uneconomic slates (6000x 9x9') means it's going in the skip so I want a cheap light weight replacement and my eye has alighted on either Sandtoft Britlock or Redland Cambrian. They seem to be roughly interchangeable but due to the Sandtoft claims of carbon neutrality and 80% recycled slate content and my limp-wristed bleeding-heart-liberal eco-guilt the Britlock is what i'm leaning towards.
Anyone worked with these?
I have bonnets on the front and wanted to wet-bed baby ridges on the small hips but Sandtoft want me to use their legged duracoat ridge. Do they feel the edge of the baby ridge won't go far enough past the join between the slates? I notice Redland have a grey plastic hip 'soaker' which seems to do the job admirably. Want a lead-free roof so can't do lead hips+ saddle. Do I need eave trays or is felt and fillet just as good? I have a breather membrane? Ta!

 

[BethesdaSlate]

Both Sandtoft Britlock and Redland Cambriams have had significant problems with uneven colour fade in the recent past, Cambrians being completely withdrawn from the market for a period this year - they have just been pulled off from a regeneration scheme in North Wales as the residents complained about them being too shiny!

Natural Welsh slate will be a lot more eco-friendly than any of these man-made products, splitting a rock with hammer and chisel v. Factory manufacture, and far less transportation.

Capital grade Penrhyn slate will be the best (and light) but unfortunately not the cheapest.

 

[underclassy]

Hmm, yes the idea of putting them on a regeneration project in Wales seems totally wooden headed - backhander anyone?
However, I could strap tarps over my roof and no one would care round here so weight is the thing. Also want it lead free for water recovery so it's not going to be flashed in traditional methods anyway. I'll do my artisan roofing bit when i've got a worthwhile project and will consider Bethesda slate then.

 

[BethesdaSlate]

I think if I was you I'd be more tempted to go for a fibre cement slate - Marley/eternit boast all sorts of eco-friendly credentials for theirs.

They are clean, very light, quick and can be easily detailed neatly (with baby ridges on the hips for example) and you can jump all over them afterwards as long as its a nice flat roof slope, you only have to look at Cambrians or Britlocks to break them.

However I can't quite bring myself to recommend them, it hurts too much !! (or have I just done that?)

Regarding eaves trays- Although we do use a lot of 5U felt at the eaves, I'd say it's easier to use plastic eaves trays as they do away with the need for a timber fillet behind the fascia.