Professional Roof Cleaning in Blackburn

Why Blackburn roofs hold moss

Blackburn gets a shade over a metre of rain a year and sits with the West Pennine Moors to the south and Pendle country to the north. Damp air, plenty of cloud cover, and long winter spells where a north or east pitch simply never dries.

Moss and algae need three things: moisture, shade and something to hold on to. A textured concrete tile on a north-facing pitch in Blackburn gives them all three for six months of the year.

Darwen and the higher ground above it are worse again, being both higher and more exposed. Roofs up towards Darwen Tower and Tockholes take a beating.

Victorian slate and modern concrete: two different jobs

The terraced streets through Audley, Little Harwood, Mill Hill and Witton are largely natural slate on timber. Slate is hard and lasts, but it is held on with nails that do not, and heavy long-term moss loading hides slipped and cracked slates until somebody goes up to look.

The estates at Shadsworth, Roman Road and out towards Feniscowles are concrete interlocking tile. Concrete has a granular surface that can be destroyed in an afternoon by the wrong equipment.

Wilpshire and Mellor have a fair amount of stone and some clay. All of it is cleaned the same way in principle and with different pressures and dwell times in practice, which is why we look first.

What a roof full of moss is actually costing you

It is not really about how it looks from the pavement. Moss acts like a sponge across the roof, so instead of the rain running off, the tiles stay saturated. Freeze that water and it expands inside the tile, then thaw it, then freeze it again. Each cycle takes a little more material off.

The laps are the other issue. Moss growing between overlapping tiles jacks them up a couple of millimetres and gives wind-driven rain a route underneath.

Then there is the guttering, which fills with everything that washes off the roof until the outlet blocks and the overflow starts running down your wall.

Our method, and why there is no pressure washer involved

The bulk of the growth is removed by hand and with steam from a roof ladder, harnessed, without walking across the tiles. The whole roof is then treated with a DDAC biocide, which is the part that actually stops it coming back.

A pressure washer is never used on a roof. It strips the coating off concrete tiles, cracks and lifts slate, and forces water under the laps into the loft. It looks like a proper job on the day and costs you a roof over the following few years.

If someone quotes you to jet wash a roof in Blackburn, get a second opinion before they start.

The biocide and the months afterwards

Scraping removes what you can see. The spores and the root structure stay in the surface of the tile, which is why untreated roofs are green again within two seasons round here.

The DDAC treatment goes across the full roof and keeps killing growth for months after we have gone. You will see the roof improve on the day and then carry on improving as the remaining dead material weathers off in the rain. That is the treatment doing its job.

Two year no-moss guarantee as standard.

Darwen, Mellor and the higher ground

Anything above the town, out towards Darwen, Tockholes, Mellor or Ramsgreave, takes more wind and more driven rain and sits in cloud more often. Those roofs want doing every three to four years and the gutters at least annually.

Properties under mature trees are on the same shorter cycle regardless of where they sit, because of the shade and the leaf fall.

What happens to the debris

All of it is cleared. Gutters emptied, downpipes run through and checked, drives and paths washed down, windows rinsed. See gutter cleaning in Blackburn for the detail on how the gutter side is done.

If the render on the same house needs attention it is usually cheaper to do it in the same visit. See render cleaning in Blackburn.

What it costs

Area, pitch, tile type, how heavy the growth is, and access. Those five things set the price and there is no sensible way to quote a roof without knowing them, which is why we do not publish a price list.

What you do get is a fixed price before we start, in writing, with no extras invented halfway through. Photos from the ground and the address are usually enough for a same-day quote.