Is steam cleaning better than pressure washing for pavers?

ICPI Tech Spec 5, the Interlocking Concrete Pavement Institute's document on cleaning concrete pavers, publishes pressure and flow figures for spray equipment, and the word steam does not appear in it.

Nor does any other association or maker document behind this answer set steam cleaning against pressure washing for pavers: not the Brick Industry Association's, the Natural Stone Institute's, Techniseal's or SEK-Surebond's. A reader weighing the two has only what each document does publish, which is pressure figures, a handful of hot-water lines and one sentence about steam on brick.

For concrete pavers, ICPI publishes pressure and flow for a sprayer, lines on the nozzle, and a note on the equipment professionals use.

ICPI's psi and gpm figures for concrete pavers sit in the service page's section on what a paver cleaning removes. The nozzle lines ICPI pairs with them are about keeping joint sand in place, the question answered under whether paver cleaning can damage the joints.

On equipment, ICPI says professionals typically use a pressure washer and an applicator for efflorescence cleaner. It names no steam equipment anywhere in the document.

Hot water does appear, in three publishers' documents, and each time it is tied to a step or a surface they name.

ICPI Tech Spec 5 rinses several listed stains, grease drippings from food, caulking, clay soil and fresh latex paint, with hot water, and it separately says cured joint sand residue "will need to be removed with hot water," with some stabilizers needing a wire brush or a pressure washer. The Brick Industry Association allows hot water in pressurized cleaning of brickwork and says low-pressure water cleaning of brick pavements "can be more effective when hot water is used and when mild detergents are applied to the pavement surface." SEK-Surebond's preparation step draws out stains with "a pressure washer (hot water preferred) or flat surface cleaner." None of the three calls hot water steam.

The order these documents give to cleaner and water is laid out under why paver cleaning means chemistry before pressure, and how clay brick and concrete pavers differ under pressure is answered under clay brick against concrete paver cleaning.

Across the association and maker documents behind this answer, one sentence names steam.

The Brick Industry Association writes that oil and tar stains on brickwork may be removed with commercially available oil and tar removers, and that "when used in a steam-cleaning apparatus, cleaners have been known to remove tar without the use of kerosene." That is a tar stain on brickwork, not a concrete paver, and it describes a cleaner run through a steam-cleaning apparatus, not steam alone as a cleaning method. None of the documents extends it to a whole driveway or a pool deck of any material.