Cost to jet wash and seal a patio (UK guide)

The short answer

Jet washing and sealing a patio in the UK is priced per square metre and costs far less than relaying it. As rough guidance, jet washing alone often runs around £5–£15 per m², and adding repointing and sealing takes a combined job to roughly £15–£30 per m², so a typical patio can cost from a couple of hundred pounds upward. The price covers pressure-cleaning, removing moss and weeds, re-pointing or re-sanding the joints, and applying the sealer. The order matters: clean first, let it dry, repoint, then seal. Sealing a porous stone patio helps it resist stains and algae and keeps its colour, though porcelain does not need it. The condition the patio starts in — how dirty and weedy — affects the cost most.

A tired patio can often be transformed by cleaning and sealing rather than replacing. Knowing what the work involves and in what order helps you budget and avoid common mistakes like sealing over damp or dirt.

Jet wash and seal costs

Jet washing aloneAround £5–£15 per m²
Clean, repoint and sealAround £15–£30 per m²
Right orderClean, dry, repoint, seal
Suited toPorous stone and concrete
Not needed onPorcelain (non-porous)

What the price covers

A full clean-and-seal job is several stages, and the cost reflects all of them. The condition the patio starts in — how much moss, algae and weed there is — drives the cleaning time most:

Jet washing: pressure-cleaning the slabs to lift dirt, algae, moss and grime. Heavily soiled patios take longer and may need a pre-treatment.
Weed and moss removal: clearing growth from the joints and surface so it does not return under the seal.
Drying: the patio must dry fully before sealing — sealer applied to damp slabs can go cloudy or fail to bond.
Repointing or re-sanding: refilling the joints with fresh pointing mortar or a brush-in jointing compound, since cleaning often washes the old joints out.
Sealing: applying the sealer, usually a couple of coats in dry weather, to protect and sometimes enhance the surface.

Because preparation is the bulk of the work, a clean, recently laid patio costs less to seal than a neglected one that needs heavy cleaning and full repointing first.

Never seal a wet or dirty patio: sealer applied over damp or dirty slabs can turn cloudy, trap the grime, or fail to bond. Thorough cleaning and full drying must come first — which is why prep is most of the cost.

Indicative costs by stage

The figures below are indicative UK guidance for each stage. Combining them into one visit is usually more economical than separate jobs.

The condition the patio starts in is the factor that moves the cleaning cost most, because preparation is the bulk of the work. A heavily soiled, weedy or moss-covered patio may need a pre-treatment and a second pass before it is clean enough to seal, whereas a lightly used patio cleans quickly. Repointing is the other variable: jet washing tends to wash out the old joints, so refilling them with fresh pointing or a brush-in compound is usually needed before sealing, and that should be allowed for in the quote.

Stage	Indicative cost per m²	Notes
Jet washing	Around £5–£15	More if heavily soiled
Repointing / re-sanding joints	Added per m²	Often needed after cleaning
Sealing	Added per m²	Two coats typical
Combined clean and seal	Around £15–£30	Better value as one visit

Indicative UK figures for guidance only; starting condition affects the total.

Is sealing a patio worth it?

Sealing is a maintenance choice rather than a necessity, and its value depends on the patio material and how you use the space:

Porous natural stone and concrete: these benefit most from sealing. It helps them resist staining from food, wine and oil, slows algae and moss regrowth, and keeps the colour looking fresh. Sandstone and limestone are common candidates.
Porcelain: dense and non-porous, porcelain does not absorb stains and does not need sealing — cleaning alone keeps it in good order.
Joint stabilising: a sealer helps bind the jointing in place, reducing washout and the weeds that follow, which cuts future maintenance.
Recurring cost: sealers wear over time and need reapplying every few years, so it is an ongoing rather than one-off cost.

What sealing cannot do is fix a structural problem — it will not re-level a rocking slab or cure a sinking patio. On a sound, porous patio that you want to keep looking sharp with less cleaning, jet washing and sealing is a sensible, cost-effective refresh. On porcelain it is largely unnecessary, and on a failing patio the money is better spent fixing the bedding first, then cleaning the surface.

Match the treatment to the material: porous stone and concrete benefit from sealing; porcelain does not need it. Sealing protects and enhances a sound patio but cannot fix a structural fault like sinking or rocking slabs.

Getting the timing and order right

A clean-and-seal job succeeds or fails on sequence and weather as much as on price, and getting these wrong wastes the money spent regardless of the rate paid. The work has a natural order, and each stage depends on the one before being done properly:

Clean thoroughly first: pressure-washing lifts dirt, algae and moss, but heavily soiled patios may need a pre-treatment and a second pass. Sealing over remaining grime traps it permanently, so the clean has to be complete before anything else.
Allow full drying: the patio must be properly dry before sealing, which can mean waiting a day or more in cooler weather. Sealer applied to damp slabs can go cloudy, fail to bond, or leave a patchy finish that is hard to put right.
Repoint after cleaning: jet washing tends to wash out old joint material, so refilling the joints with pointing mortar or a brush-in compound comes after the clean and before the seal, so the fresh jointing is protected too.
Seal in suitable weather: sealers need dry conditions and a settled forecast, usually applied in a couple of coats. Rain soon after sealing can ruin the finish, so the work is better planned for a dry spell.
Respect curing time: after sealing, the surface needs time to cure before heavy use or furniture goes back, so the job is not instant.

This is why a clean-and-seal is better done as one coordinated visit in settled, dry weather rather than piecemeal. The cost is modest compared with relaying, but it is only well spent if the order is respected: a rushed job that seals over damp or dirty slabs, or that skips repointing, can look worse than before and need stripping back. Planned around the weather and done in the right sequence, it is a cost-effective way to refresh a sound patio.

Sequence and weather decide the result: clean, dry, repoint, then seal in a settled dry spell. A clean-and-seal rushed out of order or sealed over damp slabs can look worse than before and waste the spend, however low the rate.

Frequently asked questions

How often should a patio be jet washed and resealed?

It varies with exposure, traffic and material. Many patios benefit from a jet wash once a year or so to keep moss and algae down, while sealer typically lasts a few years before it needs reapplying. A shaded, damp patio may need cleaning more often than a sunny, well-drained one.

Do I need to reseal a patio after jet washing it?

If the patio was previously sealed, heavy jet washing can strip or wear the sealer, so resealing afterwards restores protection. Jet washing also tends to wash out joint material, so repointing or re-sanding is usually needed before resealing. Cleaning, repointing and sealing are better done together as one job.

Is it worth sealing a patio, or just jet washing it?

For porous stone and concrete, sealing adds real value by resisting stains, slowing algae and keeping colour, on top of the clean. For non-porous porcelain, jet washing alone is usually enough and sealing is unnecessary. Sealing is a recurring cost, so weigh it against how much you want to reduce future cleaning.

Sources & further reading

Figures on this page are typical UK ranges drawn from published sources and depend on your specific site. They are guidance, not a quotation.