Never Jet Wash Cotswold Stone: What To Do Instead

If you own a stone property in Cirencester, Burford, Tetbury or Stow-on-the-Wold, the single most expensive mistake you can make is putting a pressure washer against the elevation.

Why pressure is the wrong tool

Cotswold limestone is soft. High pressure removes the weathered outer skin, leaving a rough face that soaks up water and greens over faster than before. Worse, it blasts out lime mortar joints, and repointing a frontage costs many times the price of a clean.

What softwashing does instead

Softwash is a low-pressure application of a biocidal cleaning solution. It is left to dwell, kills the algae, lichen and moss at the root, then is gently rinsed. The organic growth keeps dying back for days afterwards, so the finish continues to improve after we leave.

Signs your stone needs treating, not blasting

• Green or black film on north and west elevations
• Orange or grey lichen spotting
• Growth returning within months of a previous pressure clean

How long it lasts

On a treated elevation we typically see two to four years before regrowth is noticeable, depending on shade and how close the trees are. Re-treating a lightly soiled wall is much cheaper than restoring a heavily grown one.

If you are unsure what your walls are made of, send us a photo. We will tell you honestly whether it needs treating now or can wait.