I have a plastic fascia board and soffit (wood underneath) with a gutter attached, approx 17m in length. Water at one end of the gutter has overflowed causing the wood behind the fascia to rot and the gutter to lose stability. It seems to me that the wooden parts need replacing and re-covering with plastic and the gutter renewed to achieve a greater fall, allowing water to drain more efficiently.

Separately I need to replace a sagging gutter on an agricultural shed approx 25m in length. The gutter is at approx 3m height.