Steam cleaning a roof
| Steam cleaning a roof | |
| Type | Roof cleaning method |
|---|---|
| Agent | Heated water at low pressure |
| Distinguished from | Pressure washing, which uses force rather than heat |
| Defined by | Trade practice; no statute or standard |
Steam cleaning removes growth from a roof using heated water delivered at low pressure, relying on temperature rather than force. It sits between soft washing and pressure washing: more immediate than a chemical treatment, less aggressive to the covering than a high-pressure jet. No statute or published standard defines the method, so the description here is of established trade practice and carries no citation for the technique itself. What is regulated is the surrounding activity: the work is work at height,[1] and any biocidal product applied must be authorised for that use.[2]
Heat instead of pressure[edit]
The working principle is that heat kills and loosens growth, so the water does not have to strike hard enough to remove it mechanically. Pressures are far below those used in pressure washing, and the surface is not abraded in the way a jet abrades it.
That makes it usable on coverings where the surface is not renewable — the fired surface of a clay tile[3] or the applied finish of a concrete tile[4] — while still producing a result on the day rather than over a season.
Limits[edit]
It is slower than pressure washing over an area, and it requires equipment that generates and sustains heat at working height, which is a practical constraint on the size of roof it suits.
Thermal shock is a real consideration on a cold covering: heat applied to a saturated, frozen or very cold tile is not the same operation as heat applied in mild conditions. As with the other methods, the operative is generally on the roof, so the access considerations under the Work at Height Regulations apply.[1]
With and without chemical[edit]
Steam may be used alone or with a biocidal treatment applied afterwards to slow return. Where a product is used it is subject to authorisation for that use[2] and to the control of exposure for the person applying it.[5] Steam alone applies no biocidal product and does not engage the first of those.
See also
References
- abThe Work at Height Regulations 2005. legislation.gov.uk. Retrieved 2026-09-05
- abRegulation (EU) No 528/2012 concerning the making available on the market and use of biocidal products. legislation.gov.uk. Retrieved 2026-09-05
- ^BS EN 1304:2013: Clay roofing tiles and fittings. Product definitions and specifications. BSI. Retrieved 2026-09-05
- ^BS EN 490: Concrete roofing tiles and fittings. Product specifications. BSI. Retrieved 2026-09-05
- ^The Control of Substances Hazardous to Health Regulations 2002. legislation.gov.uk. Retrieved 2026-09-05