Choosing between pressure washing and soft washing

What pressure washing actually does

High-pressure water strips loose material, flaking coatings and surface dirt quickly, which suits sound, robust masonry that can take the force involved. On soft or old render, weak pointing or already-loose pebbledash, the same pressure can strip more than intended and drive water deep into the wall.

• Sound, robust masonry considered a good candidate for pressure washing
• Weak pointing and loose render treated with caution or a lower pressure
• Water ingress checked for afterwards, not assumed to evaporate harmlessly

What soft washing does instead

Soft washing uses low pressure combined with a biocide or cleaning solution to lift dirt, algae and organic growth without the mechanical force of a jet wash, which suits delicate, older or already-compromised surfaces far better.

Matching the method to the substrate

We assess pointing condition, render age and general soundness before choosing a method, rather than defaulting to whichever machine happens to be on the van that day. A wall that would benefit from pressure washing on one elevation might need soft washing on a more weathered face of the same building.

Drying time after either method

Both methods leave a wall wetter than it looks, and coating too soon after either traps that moisture under the new film. We build a proper drying period into the programme regardless of which cleaning method was used.

• Drying period built into the programme after any wall cleaning
• Moisture readings taken before coating rather than assuming a visual dry
• Weather forecast checked to avoid cleaning immediately before rain