Stone, paving and patio cleaning with optional sealing

Stone and paving cleaning removes moss, algae, lichen, weeds and ingrained dirt from patios, driveways, paths, steps, garden walls and stone plinths. The aim is a clean, even surface that is safe to walk on again, without attacking the stone itself.

Safety matters as much as appearance: green films make paving slippery when wet, especially on shaded paths and patios. In the damp coastal climate of the Baltic region, growth settles quickly on horizontal surfaces.

Stone is not just stone. Hardness, porosity and sensitivity to cleaning agents vary considerably:

Every job therefore starts with identifying the material and cleaning a test area in an inconspicuous spot. On paving we first remove weeds and compacted dirt from the joints, then clean the surface with pressure, distance and direction chosen so that as little joint material as possible is washed out. Joints can be refilled afterwards on request once the area has dried.

Why not simply use more pressure? Because damage to a stone surface cannot be undone. A roughened stone has more pores, absorbs more water and gets dirty faster than before.

Freshly cleaned stone has open pores and absorbs water and dirt easily. A sealing treatment – technically an impregnation – penetrates the pores without forming a film. Water beads off, dirt soaks in less readily and new growth takes longer, while the stone can still release moisture.

Sealing is often worthwhile on porous concrete paving, patio slabs and soft natural stone outdoors. On dense clay brick or granite it usually adds little. A true film-forming seal is different: it can change the look of the stone and how slippery it is, so we discuss the options with you first.

Organic growth such as algae, moss and lichen can usually be removed well. Not every stain disappears completely, though: deep-seated rust, oil or leaf stains often become paler but may remain visible. We tell you honestly after the test area.

Cleaning makes paving clean, not new. Sunken or loose stones, root damage and frost heave need to be relaid by a paving or landscaping company. White efflorescence on walls comes from salts in mortar or masonry and returns as long as moisture carries them to the surface.

To keep the result for longer, sweep regularly, do not leave leaves lying and pull up weeds early. For properties in Sweden and Denmark, it often makes sense to combine stone and paving cleaning with roof or facade work in one planned assignment.