Dry Ice vs Pressure Washing

Pressure washing is the most cost-effective cleaning method there is for open, robust, water-tolerant surfaces, and nothing here is an argument against using it on a driveway, a path, a wall or a truck exterior. On those jobs it is faster and dramatically cheaper, and dry ice would be an expensive way to achieve the same result.

The comparison only becomes interesting at the point where water stops being neutral. Inside an engine bay, around electrical equipment, on heritage masonry, on porous timber, or inside a food production area, the water is no longer just a carrier — it is a second problem you have created and now have to manage.

On sandstone, brick and lime mortar, high-pressure water does two things at once: it drives moisture deep into the material, and it erodes the softer binder faster than the harder aggregate. The facade looks clean and slightly rougher, and that increased roughness holds dirt and moisture more readily next time — so the cleaning interval shortens with every wash.

Dry ice removes surface soiling, biological growth and carbon staining without saturating the substrate or eroding the mortar joints. For a building you intend to keep for another century, that difference compounds. It is also why conservation specifications routinely exclude high-pressure water on historic fabric.

This is the single most common version of this question we get asked, and the answer has not changed: do not pressure-wash an engine bay.

Water under pressure finds its way past connector seals, into looms, behind the ECU and into the alternator. The failure is rarely immediate — it is an intermittent electrical fault a week or two later that costs more to diagnose than the clean cost in the first place. Dry ice does the same job with no liquid involved, and the vehicle is ready to drive the moment it is finished.