Chapter 1: Why are pine needles and moss clogging the gutters and tiles on our Burghfield Common house?
What we find
Scots pine and other trees shed constantly, and what lands on a roof does not blow off a low pitch. Needles slide into the gutters and wedge at the outlets. Seeds and leaf litter settle in the valleys and at the foot of each slope, rotting into a soft mat that holds water. Shade prevents the tiles from drying, and moss takes hold, spreading from the damp lower courses upwards.
Moss grips concrete tiles, packs the overlaps between them and lifts the edges, which allows wind-driven rain to get under them. A gutter blocked by needles overflows down the wall and soaks the fascia. The warning signs are a green or black crust on the north-facing slope, water spilling over the gutter lip in rain and fascias with a dark, damp edge.
What we fix
We clear moss by hand and apply a biocide, which stops it growing back, rather than blasting the tiles with a jet wash that can strip the surface of older concrete. Gutters and outlets are cleared on the same visit, and loose or cracked tiles are replaced as we find them. Where overhanging branches are the cause, we suggest trimming them, but that is a job for a tree surgeon, not a roofer.
Hand removal with a biocide wash is priced in typical UK guides at £748 for a small roof, £863 for an average one and £978 for a large one; jet washing comes out at £553, £638 and £723 for the same three sizes. Your fixed quote follows the survey. Our roof cleaning and moss removal page explains the method, and our guttering page covers outlets and guards.