Stone cleaning: understand the material and the achievable result
Concrete patio slabs, polished marble flooring and natural stone stairs need different treatment. The choice begins with the material, its finish and the type of soiling.
Cleaning stone indoors and outdoors
Floors, stairs, worktops, walls, paths and patios may need attention. Tracked-in dirt, grease, rust and green growth have different causes. Describe the affected area rather than prescribing a machine or chemical beforehand.
The entire surface does not always need treatment. For isolated stains, assess whether local treatment is enough or could leave a visible contrast. Normal ageing and natural colour variation are not automatically dirt to remove.
Different stones have different limits
A material name and existing care instructions help. If you do not know the stone, the company can assess it before work. You do not need to perform acid tests or scratch the surface yourself.
- Polished, matt or rough. The finish also affects suitability. A method suited to rough outdoor paving may damage polished stone.
| Material / finish | Important distinction |
|---|---|
| Marble, limestone, travertine | Acids can attack the surface; dull patches are not always deposits. |
| Granite, gneiss and similar stones | Do not assume resistance; mineral composition and previous treatments matter. |
| Sandstone and porous surfaces | Account for absorbency and a potentially delicate structure. |
| Concrete slabs and paving | Preserve surfaces and joints rather than washing joint material out. |
| Ceramic / porcelain | Different from natural stone; joints and surface treatments still matter. |
Stain removal or surface restoration?
Oil can penetrate absorbent materials. Rust may come from a metal object or from the stone itself. Treatment needs to address the specific issue. White efflorescence and recurring marks also warrant assessing the cause.
Acid etching or scratches have already changed the surface. Stronger cleaning will not necessarily correct them. Grinding, polishing and restoration are separate services with their own limitations and costs.
An agreed trial area helps assess results and colour differences. Establish any charge and what happens if the outcome is unsatisfactory. Nobody should promise complete removal of every stain without assessment.
Consider joints and cleaning water
Pressure and mechanical action must suit the paving, joints and condition. Quickly brightening a surface is not a good result if it damages the material. Clarify protection for plants, neighbouring building elements and fragile joints.
In Switzerland, biocides against algae and moss must not be used on patios, paths and paved areas. A commercially available product is therefore not automatically permitted there. Methods, loosened residue and cleaning water need site-appropriate handling.
Impregnation is a separate decision. Depending on the material and product, it can reduce stain absorption, but it does not repair cracks or protect marble from acid attack. Ask about drying requirements and possible colour changes. A general promise of years without algae is not a reliable selection criterion.
What does stone cleaning cost?
Material, area, stains, access and the intended result determine the work. Travel and preparation may mean a minimum charge for small areas. Deep stains, stairs and restoration cannot sensibly be compared with a straightforward patio clean.
Swiss examples checked in October 2026: one patio company lists CHF 8–18/m²; another lists small stone areas from CHF 250 and larger patios from CHF 450. VAT and full extras remain unclear. These are not a general market range.
One specialist lists laser cleaning from CHF 490 and states that no VAT applies. This starting offer neither recommends laser for every stone nor equates to routine surface cleaning. A suitable method and confirmed total scope remain essential.
- Core scope. Affected area, cleaning and agreed result.
- Extras. Trial area, stain treatment, repointing or restoration listed separately.
- Total cost. Travel, protection, residue, cleaning-water handling, minimum charge and VAT.
Preparing comparable quotes
Start with the location, approximate quantity, known material and visible problems. For stairs, a step count is often easier than an area measurement. There is no need to measure high walls or test the stone yourself.
Before booking, clarify access, water, electricity, furniture and when the surface can be used again. Ask about drying or closure time. Record existing damage and the limits of the expected result.
After cleaning, ask for care instructions specific to the surface, avoiding unnecessary product layers. Recurring work should reflect use and actual condition rather than being added automatically.
Frequently asked questions
Must I know the exact stone?
No. It can be assessed on site. Do not perform acid or scratch tests yourself.
Is pressure washing suitable everywhere?
No. Material, finish and joints determine the appropriate method. The company should explain its approach and assess a trial area if needed.
Will cleaning remove dull marble patches?
Not always. Etching or scratches are not simply dirt. Separate restoration may be necessary.
Is impregnation always needed afterwards?
No. Its value depends on the stone, use and existing treatment. It does not protect against every stain or form of damage.
Are joint repairs included?
Only if agreed. Cleaning, replenishing joints and replacing damaged slabs are different tasks.
