Glossary

Algae · Biocide · Block paving (cobble lock) · Gully · Imprinted concrete · Indian sandstone · Kiln-dried sand · Lance · Lichen · Pebbledash (dash) · Per m² pricing · Porcelain paving · Power washing · Pressure washing · Re-sanding · Render · Rotary surface cleaner · Run-off · Sealer · Soft wash · Tarmac

Algae

The green film on damp, shaded paving and render. Washes off, but grows back unless the spores are killed.

Biocide

A treatment that kills algae, lichen and moss. Applied after or instead of a jet wash to slow regrowth.

Block paving (cobble lock)

Concrete or clay blocks laid on sand, held in place by each other and the sand in the joints. Common on Irish driveways.

Gully

The drain grating at ground level that takes rainwater from a drive or downpipe.

Imprinted concrete

Concrete poured and stamped to look like stone or brick, with a sealer on top. The sealer wears and may need redoing after a clean.

Indian sandstone

A popular patio stone with a riven, textured surface. Marks under a strong jet, so it's cleaned gently.

Kiln-dried sand

Fine sand dried in a kiln so it flows into narrow joints. Used to re-sand block paving after cleaning.

Lance

The handheld wand on a pressure washer, with a nozzle at the end. Used for edges, steps and corners.

Lichen

Small black or grey spots that grip stone and render. Rarely shifts with water alone. A treatment left to work does more.

Pebbledash (dash)

Render with small stones pressed into it. A high-pressure jet can knock the stones out.

Per m² pricing

A rate per square metre. Measure length times width in metres to get the area. A drive 8 m by 5 m is 40 m².

Porcelain paving

Hard, dense outdoor tiles. Tough, but cleaner left on the surface can streak.

Power washing

Cleaning a hard surface with water from a pump at high pressure. Often used to mean the same as pressure washing. Some companies use hot water.

Pressure washing

Cleaning with a high-pressure jet of water. Right for concrete and most drives. Wrong for render, roofs and soft stone.

Re-sanding

Brushing new kiln-dried sand into block paving joints after power washing. HomePros.ie gives €2–€4 per m².

Render

A coat of sand and cement, or a modern acrylic or silicone render, over a block wall. Soft washed, not pressure washed.

Rotary surface cleaner

A round hood with spinning jets underneath, run over a drive or patio. It cleans an even strip and avoids the stripes a hand lance leaves.

Run-off

The dirty water and slurry from a clean. It should be rinsed away from doors and handled carefully near drains.

Sealer

A clear coating for paving or stone that slows staining and regrowth. Some sealers also help hold joint sand. Needs a dry surface.

Soft wash

Cleaning with a solution applied at low pressure that kills algae, lichen and mould, then a gentle rinse. Used on render, walls, roofs and soft stone.

Tarmac

Asphalt surfacing with stone chippings. Softer than concrete, so it's cleaned at lower pressure.