Pressure Washing in Caerphilly for Moss, Roofs & Exterior Surfaces

Why Caerphilly is harder on outside surfaces than Cardiff

Cardiff city centre is barely above sea level. Caerphilly sits in a basin ringed by high ground: Caerphilly Mountain topping 270 metres to the south, Mynydd Eglwysilan to the north west, Mynydd Machen to the east. Higher ground catches more rain, the air stays cooler, and those hillsides throw shade across whole streets from November. A north-facing wall in Trecenydd can go most of the winter without an hour of direct sun.

Surfaces that never dry grow algae, algae holds moisture, and moisture lets moss root into a paving joint or a roof tile. That is the chain we break. Getting the green off is the easy half. The work that matters is leaving the surface so regrowth is slow, because a straight rinse on a shaded valley street looks tired again by spring.

The surfaces that dominate here

Caerphilly housing runs in layers, each with its own problem. Method follows the surface, never the postcode. Slopes complicate all of it, because very little of the town is flat.

• Victorian and Edwardian terraces in Llanbradach, Abertridwr, Senghenydd and Bedwas. Pennant sandstone fronts, slate roofs, soft lime pointing. Stone and lime need low pressure and patience, never a turbo nozzle.
• Postwar estates at Lansbury Park, Penyrheol, Ty Isaf and Trecenydd. Roughcast and pebbledash render, concrete paths and garage aprons. Pebbledash turns up on more walls round here than any other finish.
• 1970s to 1990s estates at Hendredenny, Energlyn and Churchill Park. Concrete interlocking roof tiles, brick and dash walls, and tarmac drives mostly replaced by block paving.
• Newer building at Ystrad Fawr and around Bedwas. Thin coat silicone render such as K Rend, grey block paving or resin bound, and white uPVC that greens over fast on a shaded elevation.

Driveway and patio cleaning in Caerphilly

Block paving is the default drive across Hendredenny, Energlyn, Penyrheol and the newer streets off Nantgarw Road. On a slope, and most of them are on a slope, jointing sand washes down towards the kerb every wet winter until the blocks start to rock and weeds take hold. We rotary clean, pull the growth out of the joints, then re-sand with kiln dried sand once the blocks have dried. Skipping the re-sand is the usual corner cut in this trade, and it is why some drives look worse six months later than they did before.

Concrete drives and garage aprons on the older estates take a straight pressure clean, though we check for spalled patches near the gully before we start. Tarmac gets lower pressure and a wide fan, because a turbo nozzle lifts the bitumen and leaves stripes nobody can put back. Indian sandstone and riven slabs need a biocide and dwell time for black lichen, sometimes more than one application, rather than more pressure. Oil stains are a separate job with a degreaser, not a harder blast.

Once a block drive is clean and properly dry we can seal it. Sealing locks the joint sand in place and slows the algae film on shaded blocks. It needs a genuinely dry run of days rather than one dry afternoon, so we book sealing between late spring and early autumn.

Render and pebbledash: soft washing, not pressure washing

Neither pebbledash nor thin coat render should ever meet a pressure lance. On pebbledash the stones come off and water is driven in behind the render. On K Rend and similar silicone systems the lance burnishes the finish and leaves tracks down the wall. Both are permanent, and both cost far more to put right than the clean was ever worth.

We soft wash instead. Low pressure, a biocide left on the wall long enough to kill the algae and lichen off properly rather than a jet stripping the top film away, then a controlled rinse. The wall carries on improving for a week or two after we leave as the dead growth weathers off, so do not expect it to look finished the moment we pack up. On gable ends facing the mountain we use more product than on a sunny Cardiff wall, and we say so at the quote. House washing and painted masonry are handled the same way.

Roof cleaning and moss removal

Two roof types cover most of the borough. The valley terraces in Llanbradach, Senghenydd and Bedwas mostly carry natural Welsh slate, which is dense, worth cleaning, and brittle underfoot, often hanging on nails and battens that are a century old. Estates built from the 1960s onwards have concrete interlocking tiles, and that is where the serious moss lives, because the surface is porous and holds damp for months on a north slope.

We scrape the bulk off dry, then soft wash, because a lance takes the granular face straight off a concrete tile and shortens its life. Slate is treated from a tower or a pole rather than walked on. Every roof clean finishes at the gutters and downpipes, since a roof full of moss has to go somewhere and a good share of it lands in the guttering on the way down.

Gutter, fascia and soffit cleaning

Sycamore and beech along the mountain roads and around Morgan Jones Park make the autumn leaf load heavy here, and it lands on whatever moss the roof has already shed. A blocked downpipe usually shows up indoors as a damp patch above a bay window, or outside as a green stripe running down the render. We clear guttering with a ground-based vacuum on carbon poles, which matters on the narrow terraces and steep drives of the Aber valley where there is nowhere safe to foot a ladder. Fascias and soffits are washed on the same visit, and you get camera shots of the cleared line.

Decking, fences, conservatories and solar panels

Timber decking and close board fencing take low pressure and a fungicide. A lance held close raises the grain and leaves the timber furred, and drying will not bring it back. Conservatory roofs, glass or polycarbonate, are soft washed from a pole so nothing puts weight on the glazing bars. Solar panels want deionised water and a soft brush, never detergent, because the residue pulls dirt back onto the glass within weeks. Panels this side of the mountain need doing more often, since a damp shaded roof grows a film on the glass. We also take on graffiti removal and hot water work where a surface calls for it.

How a Caerphilly job runs

1. Send photos and a postcode. Call or text 07576 128903 with a couple of photos and your CF83 postcode. For drives, patios and gutters that is usually enough for a firm price. Roofs and hillside plots we come and look at first.
2. We plan water and access. We carry our own tanks, and we can work from an outside tap where that is simpler. On terraces with no side access we work out the hose run before the day rather than on it.
3. Protection goes down first. Borders, ponds, air bricks, gullies and thresholds are covered before anything is switched on. On a sloping drive we work uphill so the slurry runs away from the house instead of under the front door.
4. The right method per surface. Rotary cleaning for hard paving. Low pressure and biocide for render, roofs and timber. Where the two meet, at a render wall above a patio for example, we mask the boundary.
5. Detail, rinse, re-sand. Edges, steps, kerbs and the strip under the car are done by hand. Block paving is re-sanded. Run-off goes to a gully, not down the pavement to dry as a tide mark.
6. Walk round before payment. We walk the finished job with you and put right anything you are not happy with while the kit is still out of the van.

What it costs in Caerphilly

Prices here sit in line with Cardiff. As a guide, gutters on a three bedroom semi usually land between £80 and £150, a block paving drive of the size found on the Hendredenny and Energlyn estates between £180 and £320, a render soft wash between £250 and £450, and a roof between £500 and £900. Treat those as indicative rather than quotes. The real figure depends on square metres, how many years of growth there is, access on a steep plot, roof pitch and height, and whether the drive needs re-sanding or sealing on top of the clean.

Areas we cover around Caerphilly

We work out of our base in Cardiff. Caerphilly is about half an hour over the mountain road on the A469, or the same again round through Nantgarw on the A470 and A468 when the top of the mountain is icy. We are up that way most weeks, so there is no travel surcharge on anything in this list.

• Caerphilly town and CF83: Castle Street, Cardiff Road, Van Road, Pontygwindy, Watford Park, Hendredenny, Energlyn, Penyrheol, Trecenydd and Lansbury Park.
• The Aber valley: Abertridwr and Senghenydd, plus Llanbradach on the Rhymney line.
• East of the town: Bedwas, Trethomas, Machen and Rudry.
• Up the valley: Ystrad Mynach and Hengoed in CF82, Bargoed in CF81 by arrangement.
• Over the mountain towards us: Thornhill, Lisvane, Tongwynlais and Taff's Well in CF14 and CF15.
• Towards Newport: Risca and Crosskeys in NP11.

Commercial cleaning in Caerphilly

We take commercial work across the borough too. Shop fronts on Cardiff Road and Castle Street, pub terraces, yards and car parks on the Pontygwindy and Bedwas industrial estates, school playgrounds, forecourts and cladding. Most of it is better done outside trading hours, and our day runs from 7am to 9.30pm, seven days a week, so an early start before a shop opens is normal for us rather than a favour.

Getting a price

Call or text 07576 128903, or email Liamdunn2406@outlook.com. We have been cleaning exteriors across Cardiff and South Wales since 2019, and our Google rating is 5.0 from five reviews. Quotes are free and we do not charge to come and look. We will also tell you when a surface is better treated than blasted, and when a job is not worth doing yet.