Patios, terraces and decking · Hertfordshire, Bedfordshire and NW London

Patio cleaning in Hertfordshire

Natural stone, porcelain, resin, decking and pool surrounds cleaned and treated – including the black spot that water alone will not shift. Priced by the job, with the owner on every clean.

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Cleaned Indian sandstone patio in Little Gaddesden, Hertfordshire
Sandstone patio in Tring part way through cleaning, cleaned section against the dirty section
What we do

Patios cleaned properly, not blasted

Patio cleaning is the removal of algae, moss, black spot lichen, weeds and ingrained dirt from paving, restoring the stone or slab to its original colour. Herts Pressure Washing has been cleaning patios across Hertfordshire, Bedfordshire and NW London since 2008 – whether you call it patio cleaning, pressure washing or jet washing.

The skill on a patio is knowing what each surface will take. Indian sandstone, limestone, York stone, concrete slabs and decking all behave differently, and the wrong pressure will pit soft stone or fur up timber. We match the pressure to the material and treat what high-pressure water cannot remove.

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Surfaces

What we clean

A patio is rarely one material – stone, slabs, timber and edging often want different treatment on the same job. These are the surfaces we handle most.

Natural stone and porcelain

Indian sandstone, limestone, York stone and porcelain cleaned at a pressure the surface can take, so it is not pitted or scarred. Biocide treatments stop black spot and slippery algae taking hold.

Resin patios

Resin-bound patios and paths are now a popular choice. We clean and treat them the same way as our resin driveways – the moss comes out and the stones stay in.

Block-paved patios

Block-paved terraces and seating areas brought back to colour, with the growth cleared out of the joints and the joints refilled with kiln-dried sand.

Decking – wood and composite

Timber and composite decking cleaned at low pressure so the boards are not furred up or scarred.

Pool surrounds and terraces

Pool areas, terraces and steps cleaned and treated – the surrounds, not the water. Our Mosmatic surface cleaners can be angled away from the pool’s edge.

Steps, walls and edging

Steps, low walls, copings and edging finished with a turbo lance so the whole surface matches – the finishing touch.

Indian sandstone patio in Radlett before cleaning, with algae and black spot across the slabs
The stubborn one

Black spot is a lichen, not a stain

Those flat black dots that will not wash off are lichen, bonded into the surface of the stone. Pressure alone does not shift them – people spend an afternoon trying and end up scarring the slab instead. They need a biocidal treatment that kills the growth at the root, then a proper clean. Badly affected patios may need more than one visit.

We are trained in the use of the different biocides this process needs, and they are not all used the same way. A patio is generally pre-treated, then cleaned and rinsed, and on stubborn black spot a second treatment goes on afterwards and is left to work. We will tell you which it is and ask you to stay off the patio until it has dried in.

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How it works

From photo to finished patio

1

Send photos of the patio

Photos, plus anything you are worried about – black spot, a sunken slab, a loose step. Most quotes come back the same day.

2

One price for the patio

Priced by the job rather than the hour, and there is no VAT to add.

3

Treat first, clean second

Black spot and organic growth are treated and given time to work. On a badly affected patio most of the result is chemical, not high-pressure water.

4

Steps, joints and edges

The fiddly parts are finished with a turbo lance, then the patio is washed down with the drains left running clear.

The same Indian sandstone patio in Borehamwood after cleaning and repointing, the natural colour of the stone showing again
A separate job

Loose slabs and failed pointing

Cleaning a patio shows you what is underneath it. If the cement pointing has cracked and crumbled, or slabs have sunk and now hold water, we can put that right for you. We replace failed cement pointing with high-quality resin pointing that does not crack and crumble the way cement does, and we can relay loose slabs and level uneven surfaces. Repointing is a separate job from cleaning – it is labour intensive and most patios take a few days on their own – so it is quoted and booked in its own right. We only take on a complete repoint rather than filling in a few joints, because new pointing will not match what is already there and a patched section always shows.

Patio repointing and repairs Driveway cleaning

Covering Hertfordshire, Bedfordshire and NW London

We clean patios across all of Hertfordshire, Bedfordshire and NW London from our base in Harpenden – St Albans, Watford, Radlett, Luton, Dunstable and the North London towns around Barnet. Trading since 2008, CSCS accredited, insured to £5m with Hiscox and listed as an approved contractor by seven councils and organisations.

Areas we cover
What customers say
  • “Alex did a fantastic job returning our patio back to it’s original glory, removing years of grime and black lichen. He explained the process well, was very professional and a genuinely nice bloke. Will definitely be using him again.”

    Chris Willson

FAQs

Patio cleaning questions

Can’t see your question here? Give us a call or drop us a message on WhatsApp and we’ll give you a straight answer.

A patio is priced on the material, the size and what is growing on it – black spot and heavy lichen need treating as well as cleaning, so cost more. There is no per square metre rate. The minimum charge is £250 and there is no VAT to pay. Send photos on WhatsApp for a no-obligation price, usually the same day.

There’s no need. A lot of people hold off because they think the patio will just go green again in a few months. But a professional clean with chemical treatment lasts up to 18 months, so your patio will still look good well into next year. Book between September and February to get 10% off with our low-season rates – and beat the spring rush, when we’re at our busiest.

Yes, in most cases. Black spot is a lichen that grows into the stone, so pressure alone will not remove it – it needs a trade-strength biocidal treatment that kills the growth at the root, followed by a proper clean. Badly affected patios sometimes need a second or third visit, priced separately and agreed with you before we do it.

Indian sandstone, limestone, York stone, porcelain, terracotta, resin-bound, concrete slabs, block paving, pool surrounds and decking (timber or composite) – plus the steps, walls and edging around them. Each is cleaned at a pressure the material can take.

Not when the pressure is matched to the stone. Softer stone is cleaned at lower pressure with more treatment and less force, which is why we treat growth chemically rather than trying to blast it off. Domestic machines, inexperience and close-range lances are what cause pitting.

Yes – wood and composite decking, and the area around a pool rather than the water itself. Both are cleaned at lower pressure than paving so the surface is not scarred or striped.

Cleaning does not make sound pointing fail, but it does expose pointing that has already cracked or crumbled. If that happens we can repoint with a high-quality resin pointing that does not crack out like cement, and relay any slabs that have sunk.

No, and we would talk you out of it. Sealants flake within months, trap moisture under the stone in our climate and make greening and black spot worse rather than better – as well as making the next clean harder. Our professional advice is to stay well away from them.

An outdoor tap and a way through to the patio. Move furniture and pots aside if you can and we will work around anything too heavy to shift. If there is no outside tap at all, tell us when you send the photos and we will let you know what is possible.

Yes – block paving, resin-bound, tarmac and concrete drives are all on our driveway cleaning page. Most customers have the drive and patio done on the same visit, which works out cheaper than two call-outs.

Get in touch

Get a fast, no-obligation quote

Send us a couple of photos on WhatsApp and we’ll come back with a price – usually the same day.

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Established 2008

4.9★ from 80 Google reviews

Council approved