sergiu

If it helps it is not lead lined. Looks like gpr at the bottom and cromapool or acripool sealant.

What's the best solution here? My gutter is sloped the wrong way. 25mm over 4,5 metres. My idea was to add a layer of felt or some self leveling compound Liquid rubber ' inside the gutter to correct the slope would work? If yes what's the best? Many thanks