Thanks for the replies.
If I was to waterproof the roof prior to slates on battens and counterbattens, surely the fixing of the counterbattens through the waterproof layers to the OSB/sarking would defeat the purpose of a waterproof membrane?
Looking for a bit of guidance here.
I'm trying to find a slate (or other product with natural slate appearance) to fit to a new lean to roof with an angle of only 12 degrees.
It's a planning stipulation that it's to be slate appearance but I've only found the Tapco slate which is suitable for...