Professional Roof Cleaning in Preston, Lancashire

Flatter ground, more wind, the same moss problem

Preston is not hemmed in by hills the way the east Lancashire towns are, and people sometimes assume that means less trouble with moss. It does not work out that way.

What Preston gets instead is wind and moisture off the Ribble estuary and the coastal plain, around a metre of rain a year, and very little shelter. Driven rain hits elevations and roofs harder here than it does in a valley, and the air carries damp in off the water for a lot of the year.

The result is the same green north pitch, just arrived at by a different route.

The Ribble, the estuary and what the damp does

Properties closer to the river and out towards the estuary sit in damp air far more of the time. Penwortham, Walton-le-Dale and the low ground near the Ribble see it most.

Damp air means slower drying, and slow drying is the whole story with roof moss. It is not about how much rain falls, it is about how long the tile stays wet afterwards.

Algae usually shows up first as a general darkening of the pitch, then lichen as crusty patches, then moss thickening along the lap lines. By the time it is obvious from the pavement it has usually been established for two or three years.

New build estates and their roofs

Preston has a lot of newer housing, out at Cottam, Broughton, Ingol and the developments north of the city. Those roofs are almost all concrete interlocking tile, often quite smooth and light coloured, and the algae shows on them early and obviously.

A ten year old roof on one of those estates is frequently the one we get called to, because the staining looks dreadful long before there is any structural moss problem. That is usually a straightforward soft wash and treat.

Older stock through Fulwood, Ashton and Longridge has more slate and more variety, and wants a more careful survey first.

How we actually clean a roof

Inspect first and photograph anything slipped, cracked or already failing. Remove the growth by hand and with steam from a roof ladder, harnessed, avoiding foot traffic on the tiles.

Then treat the entire roof with a DDAC biocide, not just the visibly affected parts. The biocide keeps killing growth for months afterwards, which is what stops the roof being green again in two seasons.

Then clear the gutters and downpipes of everything that has come down, and wash off the drive, paths and windows.

What pressure washing does to a tile

The granular surface on a concrete tile is what makes it weather-resistant and gives it its colour. A pressure washer takes that off. The tile underneath is porous, so it holds water, breaks down faster through frost cycles, and grows moss more readily than it did before it was cleaned.

On the newer smooth tiles around Cottam and Broughton it also leaves visible lance striping that never fully goes.

And on any roof, high pressure pushes water up under the laps and into the roof space. We will not do it, and we would not recommend letting anybody else.

Longridge, Fulwood and the older stock

Longridge, the edge of the Ribble Valley and the older parts of Fulwood have more stone, more slate and more mature trees. Trees mean shade and leaf fall, which means shorter cleaning cycles and gutters that need doing annually without fail.

Slate roofs also hide their problems well under moss. On an older property we would rather find the slipped slates during the survey than have you find them in the first winter gale afterwards.

Gutters and the tidy up

Clearing the gutters is part of every roof clean here, because a roof clean pushes a lot of material into them. Downpipes get run through and checked.

See gutter cleaning in Preston for how the gutter work is done, and render cleaning in Preston if the render on the same property could do with attention while we have access.

What a Preston roof clean costs

Area, pitch, tile type, severity of growth and access. A modern estate semi with easy access is at the lower end. A large detached with multiple pitches, dormers and a conservatory in the way is at the other.

Fixed price, in writing, before we start, with no extras appearing partway through. Address plus a couple of photos from the ground is usually enough for a same-day quote.