Conservatory Roof Cleaning Cardiff

What a conservatory roof collects

Conservatory roofs sit at a shallow pitch, usually somewhere between 15 and 25 degrees, so they never get the scouring rain that sheets off a steep tiled roof. Water sits, dries and leaves behind whatever it was carrying: a green algae film, black spotting where panels stay damp, moss creeping out of the ridge and the bar joints, tree sap, and bird droppings along the ridge line.

Roath, Penylan, Cyncoed and Lisvane are the worst for it because of the mature trees. Anything under a canopy collects leaf litter that rots down to a black mulch in the gutters. A north-facing roof barely dries between October and March, so the algae gets months of growing weather. Most people notice from inside first, when the light coming through the roof goes flat and faintly green.

Nobody should be standing on your conservatory roof

A conservatory roof is not built to carry a person. The panels sit in glazing bars on rubber gaskets, and the load runs through the bars into the frame, not through the sheet. Polycarbonate flexes under a boot and lets go at the fixings. On a glass roof the risk is the bar deflecting and the sealed unit shifting in its gasket.

So the whole job is done from the ground. A carbon fibre water-fed pole reaches the ridge of a standard lean-to or Victorian conservatory from the lawn. The brush is soft bristle, and the water is filtered and deionised so it carries almost nothing dissolved, which means it dries off without spotting and needs no detergent. No ladders, and no weight anywhere on the structure.

The green line down the edge of every panel

This is the part a quick wash always misses. Each panel sits on a gasket inside the glazing bar, and that junction holds a line of water long after the middle of the panel has dried. Algae colonises the wet edge and creeps under the capping. From inside it reads as a green stripe down both sides of every panel, which is why a roof can look filthy while the open glass looks clean. Clearing it means working the brush along the bar itself, not sweeping across the panels.

What the clean covers

• Glass or polycarbonate roof panels, including the shaded strip at each panel edge
• uPVC glazing bars, capping strips and the gasket lines between the panels
• The ridge, the finial and any crestings, where moss and droppings start
• The box gutter where the roof meets the house, cleared by hand and flushed through
• The conservatory's own gutters and downpipes, plus the house gutters, fascias and soffits above it
• Frames, transoms, sills and the outside face of the windows and doors
• The dwarf wall, and the render or brickwork behind a lean-to

The gutter above matters more than people expect. If it is blocked it overflows onto the roof and streaks it within weeks, so cleaning the panels and leaving the gutter full is money wasted.

Glass and polycarbonate are different jobs

Polycarbonate

Most older Cardiff conservatories have multiwall polycarbonate: hollow sheets with flutes running down the slope and a thin UV layer on the top face only. Pressure washing it is the worst thing you can do to a conservatory roof. It abrades the UV layer that stops the sheet going brittle and yellow, and it drives water into the flutes past the breather tape at the ends. Algae growing inside a flute cannot be reached from either face. At that point the roof is a replacement, not a clean.

Glass

Glass roofs are sealed units, often tinted for solar control and sometimes carrying a self-cleaning coating. That coating is a few nanometres thick and needs daylight on it to do anything, so scrapers, abrasive pads and strong alkaline cleaners strip it, and a film of algae switches it off. A coated roof still needs washing. It just needs washing gently, with a soft brush and pure water.

Box gutters and the join with the house

The box gutter is the flat channel where a lean-to roof meets the house wall. It is the highest risk point on the structure and almost nobody looks at it. It sits under the eaves, catches what the house gutter overshoots, and has very little fall. Pack it with mulch and moss and it backs up, then water tracks under the flashing and shows as damp on the inside wall or a stain on the plaster above the doors.

We clear it by hand, flush it, and check the outlet into the downpipe actually runs. We look at the flashing and the sealant while we are there, and if the lead has lifted or the sealant has perished you get told and shown a photo. We clean; we will not pretend a failed flashing is a cleaning problem.

Conservatory cleaning in Cardiff is not a window round

Search for conservatory cleaning in Cardiff and nearly every result is a window cleaning company. That is not a dig at window cleaners. They have the pole and they will make the glass look good. The difference is everything that is not glass: moss in the ridge, a packed box gutter, algae bedded into the gasket lines, black growth on the bars, and a plan for where the debris and the water end up.

This sits inside a wider exterior cleaning round run out of a unit in Cardiff. If the conservatory roof is green, the render behind it and the patio in front of it usually are too, and one visit costs less than three separate ones. We have been cleaning exteriors around Cardiff since 2019, and our Google rating is 5.0 from five reviews.

How the job runs

1. We look before we touch. Panel type first, glass or polycarbonate, then the gaskets and capping, the box gutter, and whether the house gutters above are clear. Anything broken or leaking, you hear about it before we start.
2. Solid debris comes off first. Leaves, twigs, moss clumps and gutter mulch are lifted by hand and bagged, not washed down the slope. Flushing that lot into the downpipes only moves the blockage somewhere worse.
3. The roof is washed from the ground. Soft brush on the water-fed pole, panel by panel down the slope, with the bars, capping and gasket lines worked along their whole length. Filtered water only, so nothing is left behind on the panels to attract dirt.
4. Frames, glass and the base. Frames, sills, transoms and the outside of the windows and doors, then the dwarf wall and the render behind. Stubborn staining gets a soft wash, which is a cleaning solution put on at low pressure and left to work, rather than more pressure.
5. Rinse, check, clear up. A pure water rinse from the ridge down, then we look at it from the garden, from the doorway and from inside, because the panel edges are where anything missed shows. The bagged debris leaves with us.

How often it needs doing

Once a year suits most Cardiff conservatories. Under trees, or on a north-facing roof that sees no direct sun after September, six to nine months is more realistic. Leaving it five years is a false economy: moss holds water against the bars and the gasket line, and that is where leaks start.

What changes the price of conservatory cleaning

As a guide, a straightforward lean-to of around three by three and a half metres, with the frames done and the gutter cleared, tends to land between £90 and £180. Bigger Victorian, Edwardian and P-shaped roofs, heavy established moss, or a box gutter needing a full clear out run higher, commonly £180 to £300.

Those are indicative bands rather than a quote. What moves the price is size and shape, glass or polycarbonate, how long since the last clean, whether the box gutter is included, and access: a roof reached off a level lawn is quicker than one over a raised deck or a steep terraced garden. Send a photo from the garden with the whole roof in frame and you get a real number.

Ready when you are: arrange your conservatory cleaning quote

We cover Cardiff and South Wales, from Canton, Pontcanna and Llandaff across to Roath, Penylan, Cyncoed, Lisvane, Llanishen, Whitchurch, Rhiwbina and Radyr, and out to Barry, Newport and beyond. Call or text 07576 128903, or email Liamdunn2406@outlook.com. We answer from 7:00 to 21:30, seven days a week, and quotes are free.