Block Paving Pressure Washing

A driveway is the part of a home people see before they see the home. It takes the weather, the traffic and the years without ever complaining, and precisely because it does, it is the last thing anyone thinks about — right up until the morning they notice it, and then they cannot stop noticing it. Most of what people actually want from a clean is not perfection. It is to stop feeling faintly embarrassed by the front of their own house.

What builds up there is less dramatic than it looks. Road silt and brake dust settle out of the air. Tyres lay down a fine rubber film along the wheel tracks. Algae colonises the pore structure of the concrete wherever the surface holds damp, and moss takes the joints, because a joint full of kiln-dried sand is a seed bed with drainage built in. None of that is a fault in the paving. It is what happens to any porous mineral surface left outdoors.

The work itself was straightforward, which is worth saying out loud, because most of it is. A rotary flat surface cleaner takes the open field: it spreads a fixed volume of water across a wide arc, so no part of the surface ever carries the whole flow at once. But a rotary head is a circle, and a driveway has edges, corners and awkward returns that a circle will never reach. Those get finished by lance, held back at distance, with the nozzle chosen for what is there.

Which brings up the thing the trade rarely bothers to explain. Pressure is not one setting picked in the morning and left alone all day. It is jet size and force matched to whatever is in front of you — a wider fan and less power on softer, less compact materials, tighter and closer only where a deposit genuinely demands it. Sandstone is treated very differently from concrete block. Getting that judgement wrong is what ruins surfaces; the machine is never the problem.

Because the face of a concrete block is a thin skin of fine aggregate and pigment sitting over a coarser body. Put enough energy into it and that skin comes away, the coarse stone underneath shows through, and the block reads as tired from that day on. It is a one-way trip. A drive can be cleaned properly a hundred times and be fine; twice with the wrong jet held too close, and it is not.

Oil is where honesty matters more than technique. Hydrocarbons are hydrophobic and they travel into the pore network by capillary action, so by the time a stain looks old it is not on the block — it is in it. Water will not move it and no amount of pressure reaches where it has gone. A good clean usually lightens it, sometimes considerably, so it stops being the thing your eye goes to. Nobody honest will promise it disappears.

There are two routes that genuinely work. A poultice is the old one and still the best understood: an absorbent powder mixed with a solvent, spread thickly over the stain, covered, and left a day or two, which reverses the capillary action and draws the oil back out as the solvent evaporates. The other is a biological degreaser, of the kind Smartseal make, which is not a detergent at all — it carries live bacteria that digest the hydrocarbon where it sits.

Both need managing expectations. Manufacturers of the biological removers are candid that they lift most of a stain rather than all of it, and that porous surfaces often need a second application, because the first round of activity draws deeper oil back up to the surface. Synthetic oils behave differently again and may not respond. Nothing here is magic, and the household tricks — bicarbonate paste and the rest — do not have the chemistry to reach ingrained oil at all.

If a stain still will not go, block paving has a quiet advantage that slabs and tarmac do not: a single block can be lifted out and replaced. Contractors very often leave a stack of spares behind a shed or under a hedge for exactly that reason. A bolster chisel and an afternoon solves what no chemistry was ever going to win. It is worth finding out whether you have those spares before spending money on a treatment that was never going to succeed.

On this drive nothing was applied at all, because the customer did not want chemicals used, and that is entirely their call to make. A driveway is where dogs walk, where children sit down without thinking, and where people with health conditions live on the other side of the door. Chemistry should be offered, explained and consented to — never assumed, and never quietly included in a price. Declining it is a legitimate specification, not a lesser service.

The most useful thing we tell customers is the part that earns us nothing. After a heavy clean, a drive holds its condition for a full year if it gets ten minutes of attention occasionally: a diluted algicide such as Patio Magic through an ordinary watering can, a weed treatment in the joints, and a stiff brush over the worst of it. That is the whole secret, and it is the difference between an annual clean and a rescue.

One last thing, because it is the reason this job exists at all. In the summer of 2026 our van and our tools passed out of our hands in a dispute we are still working to resolve — work we had already paid for, in advance. It stopped the business dead, and we told our community what had happened. What came back was more than we knew how to accept gracefully: people rang, people offered, and in the end we were given a van. This customer did not have to call us. They called anyway.