Fascias, soffits and cladding: the strip everyone forgets

What the discolouration actually is

Three things overlap. Green algae grows in the permanently shaded soffit and on the north side. Black streaking on fascias is airborne dirt washed down and concentrated by run-off from the gutter lip. Yellowing on south-facing uPVC is UV degradation of the plastic itself and is not dirt at all, which is why the sunny elevation never comes up as bright as the shaded one no matter how long you scrub.

This guide sits under our Gutter Cleaning & Clearing work, covering 20-mile radius of Plymouth.

Why abrasives are a mistake

Cream cleaners, scouring pads and wire wool remove the smooth outer skin of uPVC. The surface then holds dirt in the micro-scratches, so it looks dirty sooner and each subsequent clean is harder. The damage is cumulative and permanent. The right approach is a soft brush, a suitable detergent and time, not more abrasion.

How it is cleaned properly

Water-fed pole with a soft brush handles most domestic properties from the ground, which avoids repeatedly repositioning ladders along an eaves run. Detergent is applied, the surface is agitated gently along its length, and pure water rinses it so nothing dries as a streak. Bargeboards on a gable and the underside of soffits need deliberate angles rather than a quick pass.

Doing it with the gutters

Cleaning fascias without clearing the gutter behind them is a short-lived result: the next downpour brings dirty water over the lip and straight down the freshly cleaned board. The gutter exterior, the fascia and the soffit should be done as one item, and it is far more efficient than booking them separately.

Vents, mesh and bird entry

Modern soffits have ventilation strips that must stay clear to keep the roof void dry. They clog with dust, cobwebs and paint from previous work. While cleaning, it is worth checking for gaps where birds have got into the eaves, which is common on older conversions and shows as a hole at the fascia-soffit junction.

Painted timber instead of plastic

Older properties still have timber fascias and soffits, and these need washing gently rather than treating like plastic. The clean often reveals flaking paint and soft spots, particularly behind a gutter that has been overflowing. That is useful information: rotten fascia found early is a board replacement, found late it is a roof edge repair.

When cleaning will not be enough

If uPVC has yellowed through UV, is cracked, has become brittle, or the fixings have pulled through, cleaning improves it but does not solve it. Similarly, boards that have distorted or are supporting a sagging gutter need replacing. We will tell you honestly when we think a clean is polishing something that has reached the end of its life.

How often

Every one to two years alongside the gutter clear keeps them consistently white. Left for five or ten years, the algae establishes properly and the black streaking becomes ingrained, so the clean takes much longer and the result is not quite as good. Like most exterior maintenance, frequent and light beats rare and heavy.