Professional terrace cleaning in French-speaking Switzerland
The terrace is a living space in its own right, particularly valued in French-speaking Switzerland where fine weather invites you to enjoy the outdoors. Whether it is a raised wooden terrace with a view of Lake Geneva, a natural stone terrace at a Fribourg villa or a tiled balcony in a Lausanne apartment building, this outdoor space deserves regular professional maintenance to preserve its appearance and durability.
Throughout the seasons, Swiss terraces are put to the test: winter frost, rain, snow, summer UV rays, spring pollen, autumn leaves. Moss, green algae, lichen and various stains gradually take hold, making the surface slippery, unsightly and potentially dangerous. SOS Nettoyage is the terrace cleaning specialist in French-speaking Switzerland. We restore your terrace to its original shine using techniques tailored to each material.
Why have your terrace professionally cleaned
Safety first
A terrace covered in moss, green algae or lichen becomes extremely slippery, especially when wet. In Switzerland, falls on outdoor surfaces are a frequent cause of domestic accidents, particularly among the elderly. A professional clean by SOS Nettoyage eliminates these growths and makes your terrace safe and usable in all weather conditions.
Preserving materials
Vegetation (moss, lichen) does not simply sit on the surface: their roots penetrate the pores of the material, creating micro-cracks that worsen with frost. On a wooden terrace, moss retains moisture and accelerates the rotting of boards. On stone or tiles, lichen chemically attacks the surface and causes irreversible damage if left untreated.
Regular professional maintenance significantly extends the lifespan of your terrace, representing considerable savings compared to the cost of a complete rebuild.
Aesthetics and property value
A clean, well-maintained terrace is a major aesthetic asset for your home. It visually extends the living space and contributes to your property’s value. Conversely, a greyish, moss-covered and stained terrace makes a poor impression and can devalue your property by several thousand francs.
Cleaning by material type
Wooden terrace
Wooden terraces are very popular in French-speaking Switzerland, with a range of wood species:
- Exotic wood (teak, ipé, cumaru, padouk): naturally resistant but turns grey over time
- Treated European wood (pressure-treated pine, larch, Douglas fir): less resistant, requires more frequent maintenance
- Thermally modified wood (thermo-treated ash, poplar): good durability, specific surface
SOS Nettoyage protocol for wood:
- Sweeping: removal of leaves, debris and coarse dust
- Pre-wetting the surface
- Application of a de-greying agent: a specific product that breaks down grey fibres oxidised by UV rays and restores the wood’s natural colour. De-greying agents generally contain oxalic acid or citric acid
- Dwell time: 15 to 30 minutes depending on the product and degree of greying
- Mechanical brushing with a soft-bristle brush in the direction of the grain
- Rinsing with clean water at low pressure (maximum 80-100 bar, wide-fan nozzle, minimum distance of 30 cm)
- Drying: at least 24 to 48 hours
- Optional application of a saturator or protective oil
Important: SOS Nettoyage never uses a high-pressure cleaner at full power on wood. A jet that is too powerful (> 120 bar) or too close destroys the surface fibres, gouges the wood and considerably reduces its lifespan. We exclusively use low-pressure techniques combined with professional products.
Natural stone terrace
Natural stone (granite, sandstone, quartzite, travertine, slate, limestone slabs) is a noble and durable material, very much present in Swiss architecture.
SOS Nettoyage protocol for natural stone:
- Sweeping and debris removal
- Pre-wetting the surface
- Application of a special stone cleaner: neutral or slightly alkaline pH depending on the stone type (never acid on limestone or marble!)
- Mechanical brushing with a brush suited to the stone’s hardness
- Anti-moss treatment: application of a biocide product that eliminates moss, algae and lichen in depth
- Rinsing at medium pressure (150-200 bar) with a rotary nozzle for an even result
- Drying and result inspection
- Optional application of a water repellent (sealant) to protect the stone against stains and water absorption
Points of attention by stone type:
- Granite: very resistant, handles high pressure well. Main risk: moss in joints
- Sandstone: more porous, requires gentler cleaning and a water repellent
- Travertine: very porous, acid-sensitive. Cleaning exclusively at neutral pH
- Slate: resistant but can delaminate if cleaned too aggressively. Brush in the direction of the grain
- Limestone: very acid-sensitive. Gentle cleaning mandatory
Tiled terrace
Outdoor tiles (porcelain stoneware, glazed stoneware, terracotta) are very common for terraces and balconies in French-speaking Switzerland.
SOS Nettoyage protocol for tiles:
- Sweeping debris and dust
- Pre-wetting the surface
- Application of a professional detergent suited to the tile type
- Mechanical brushing or single-disc machine pass for large areas
- Grout cleaning: this is often where moss and dirt accumulate most. We use a specific cleaner and a fine brush
- Rinsing at moderate high pressure (100-150 bar)
- Optional application of a preventive anti-moss product
Points of attention:
- Porcelain stoneware: very resistant, tolerates most cleaning techniques
- Terracotta: porous, acid-sensitive. Requires gentle cleaning and a waterproofing treatment
- Glazed tiles: the glaze can be scratched by overly abrasive tools. Cleaning with soft brushes only
- Grout: check the condition of grout after cleaning and recommend regrouting if necessary
Composite terrace (WPC)
Composite boards (wood-polymer, or WPC — Wood Plastic Composite) are increasingly popular in Switzerland for terraces. They offer good weather resistance but still require regular maintenance.
SOS Nettoyage protocol for composite:
- Sweeping and debris removal
- Pre-wetting the surface
- Application of a gentle composite-specific cleaner (neutral pH, no bleach)
- Brushing in the direction of the grooves with a soft brush
- Rinsing at low pressure (maximum 100 bar, wide nozzle)
- Natural drying
Important: Composite must never be treated with bleach, acidic products or strong solvents that could discolour or damage the surface. High pressure should be avoided as it can damage the protective surface layer. SOS Nettoyage exclusively uses products validated by composite board manufacturers.
Concrete terrace
Concrete slabs (smooth concrete, exposed aggregate concrete, printed concrete) are an economical and durable option for terraces in Switzerland.
SOS Nettoyage protocol for concrete:
- Sweeping debris
- Treatment of specific stains (oil, grease, rust) with targeted products
- Application of an alkaline cleaner to dissolve moss and soiling
- High-pressure cleaning (200-300 bar) with a rotary nozzle for an even result
- Deep biocide anti-moss treatment
- Optional application of a water repellent or sealer to protect and enhance the surface
Concrete is a robust material that handles high-pressure cleaning well, delivering a spectacular “like new” result.
Anti-moss treatment: essential in Switzerland
Why moss thrives in French-speaking Switzerland
The climate of French-speaking Switzerland — with its regular rainfall, damp winters and moderate temperatures — provides ideal conditions for moss, green algae and lichen growth. Terraces facing north or in shade are particularly affected.
Factors promoting growth:
- Persistent moisture: shaded areas, proximity to trees
- Lack of drainage: standing water on the surface
- Porous surface: concrete, stone, tile grout
- Organic matter: dead leaves, dust, soil that serve as growing medium
The SOS Nettoyage professional treatment
Our anti-moss treatment includes:
- Mechanical removal of visible moss (brushing, high pressure)
- Application of a professional biocide that penetrates the pores of the material and destroys spores in depth
- Action time: the product continues to work for several weeks after application
- Preventive effect: regrowth is delayed by 6 to 12 months depending on conditions
For heavily exposed terraces, SOS Nettoyage recommends anti-moss treatment twice a year (spring and autumn) for optimal protection throughout the year.
Seasonal maintenance of your terrace
Spring: the major restoration
Spring is the ideal season for a complete clean of your terrace after winter. The SOS Nettoyage spring intervention includes:
- In-depth cleaning suited to the material
- Curative and preventive anti-moss treatment
- Inspection of grout, boards and fixings
- Application of protective product (oil, saturator, water repellent depending on material)
- Personalised advice for summer maintenance
Summer: enjoy with peace of mind
If the spring clean has been carried out, the terrace is in perfect condition for the fine season. Simple regular sweeping and an occasional rinse with a garden hose are enough to maintain cleanliness. In case of accidental stains (barbecue, wine, sauce), SOS Nettoyage can intervene on a one-off basis.
Autumn: preparing for winter
In autumn, SOS Nettoyage recommends:
- An intermediate clean to remove summer residue and the first fallen leaves
- A second preventive anti-moss treatment before the damp winter
- Cleaning of channels and drainage grates to ensure drainage during the rainy months
- For wooden terraces: possible application of an autumn saturator to protect the wood during winter
Winter: precautions
During the Swiss winter, the terrace is particularly vulnerable. Some tips:
- Clear snow regularly with a plastic shovel (no metal on wood or stone)
- Do not use de-icing salt on natural stone, wood or composite (salt attacks materials and promotes frost-induced cracking). Prefer fine gravel or sand
- Do not use hot water to de-ice a terrace: thermal shock can crack stone or tiles
- Store garden furniture or protect it with covers
Post-cleaning protection options
Water repellent (sealant)
The water repellent creates an invisible barrier that prevents water from penetrating the pores of the material. Water beads on the surface instead of being absorbed.
Advantages:
- Reduces water absorption by 90% or more
- Limits moss and algae growth
- Protects against stains (grease, wine, sauce)
- Prevents freeze-thaw damage: by preventing water penetration, the water repellent reduces frost damage
- Duration: 3 to 5 years depending on the product and exposure
Suitable materials: natural stone, concrete, porous tiles, grout
Indicative price: 5 – 15 CHF/m² (product + application)
Saturator / wood oil
The saturator is a wood-specific product that nourishes and protects the fibres in depth.
Advantages:
- Nourishes the wood and prevents drying out
- UV protection: slows down greying
- Water repellency: beading effect
- Preserves the natural colour of the wood
- Duration: 1 to 2 years (annual reapplication recommended)
Indicative price: 8 – 18 CHF/m² (product + application)
Concrete sealer
The concrete sealer creates a protective film on concrete that facilitates maintenance and improves aesthetics.
Advantages:
- Wet look or gloss effect that is very aesthetic
- Protection against stains (oil, grease)
- Facilitates daily cleaning
- Duration: 3 to 5 years
Indicative price: 10 – 20 CHF/m² (product + application)
Terrace cleaning prices in French-speaking Switzerland
| Service | Indicative price |
|---|---|
| Wood terrace cleaning (standard) | 8 – 15 CHF/m² |
| Wood terrace cleaning + de-greying + saturation | 15 – 25 CHF/m² |
| Natural stone terrace cleaning | 10 – 18 CHF/m² |
| Tiled terrace cleaning | 8 – 14 CHF/m² |
| Composite terrace cleaning | 8 – 12 CHF/m² |
| Concrete terrace cleaning (high pressure) | 8 – 15 CHF/m² |
| Anti-moss treatment (alone) | 3 – 8 CHF/m² |
| Water repellent application | 5 – 15 CHF/m² |
| Wood saturator application | 8 – 18 CHF/m² |
| Minimum intervention fee | 200 CHF |
Prices depend on the total surface area, the material, the level of soiling and the accessibility of the terrace. Request your free, no-obligation quote from SOS Nettoyage for an accurate price.
Why choose SOS Nettoyage for your terrace
- Multi-material expertise: we master techniques specific to each type of surface
- Professional products adapted and respectful of materials
- State-of-the-art equipment: adjustable low/high pressure cleaners, single-disc machines, rotary brushes
- Respect for materials: never an overly aggressive technique, never an unsuitable product
- Preventive treatment included for a lasting result
- Free, no-obligation quote after assessment of your terrace
- Service throughout French-speaking Switzerland: Genève, Lausanne, Montreux, Sion, Neuchâtel, Fribourg
Service areas
SOS Nettoyage provides terrace cleaning throughout French-speaking Switzerland:
- Canton de Genève: Genève, Carouge, Vernier, Lancy, Meyrin, Grand-Saconnex
- Canton de Vaud: Lausanne, Montreux, Vevey, Nyon, Morges, Yverdon-les-Bains, Rolle, Pully
- Canton du Valais: Sion, Sierre, Martigny, Monthey, Crans-Montana
- Canton de Neuchâtel: Neuchâtel, La Chaux-de-Fonds, Le Locle
- Canton de Fribourg: Fribourg, Bulle, Morat, Estavayer-le-Lac
- Canton du Jura: Delémont, Porrentruy
Whether your terrace is a small city balcony or a large panoramic terrace by the lake, SOS Nettoyage offers a tailored service suited to your needs.
Request your free quote
Has your terrace lost its shine? Has moss invaded the grout? Has the wood turned grey? SOS Nettoyage is your partner for bringing your outdoor space back to life. Contact us to get your free, no-obligation quote. We visit at no charge to assess your terrace and propose the most suitable solution.
Also discover our facade cleaning services for a complete exterior restoration of your home.
Frequently asked questions about terrace cleaning
How often should I have my terrace professionally cleaned?
For most terraces in French-speaking Switzerland, a professional annual clean (in spring) is sufficient. If your terrace is particularly exposed to shade and moisture, or if it is wooden, a second clean in autumn is recommended. Anti-moss treatment can be reapplied twice a year for areas highly prone to vegetation growth. SOS Nettoyage will advise you on the ideal frequency when assessing your terrace.
Can I use a Kärcher high-pressure cleaner on a wooden terrace?
We strongly advise against it. A domestic high-pressure cleaner used at full power or too close can destroy the surface fibres of the wood, create unsightly grooves and significantly reduce the lifespan of the boards. If you use a high-pressure cleaner, the pressure should not exceed 80-100 bar, with a wide-fan nozzle, at a minimum distance of 30 cm from the wood. SOS Nettoyage uses low-pressure techniques combined with professional products for an optimal result without damaging the wood.
How do I remove grease stains from a stone terrace?
Grease stains (barbecue, oil) on natural stone are stubborn because grease penetrates the pores of the material. SOS Nettoyage uses absorbent poultices (clay + solvent) that draw out grease from deep within, combined with professional alkaline degreasers. Applying a water repellent after cleaning prevents future stains by stopping grease from penetrating. For fresh stains, immediately sprinkling fuller’s earth or bicarbonate of soda can limit penetration.
Does high-pressure cleaning damage the terrace grout?
A high-pressure clean carried out by a professional like SOS Nettoyage should not damage grout in good condition. However, grout that is already weakened, cracked or partially detached can be degraded by water pressure. Our technicians systematically assess the condition of grout before the intervention and adjust the pressure accordingly. If regrouting is necessary, we inform you and can refer you to a qualified tradesperson.
How much does it cost to clean a 30 m² terrace?
For a 30 m² terrace, indicative prices are as follows: standard clean (no treatment): 240 to 450 CHF; clean with anti-moss treatment: 330 to 690 CHF; complete clean with protection (water repellent or saturator): 480 to 900 CHF. The exact price depends on the material, level of soiling and accessibility. Request your free quote from SOS Nettoyage for an accurate price.
Is bleach effective for cleaning a terrace?
Bleach is strongly advised against for terrace cleaning. While it does kill moss on the surface, it has numerous drawbacks: it discolours wood and stone, it destroys micro-organisms in the surrounding soil, it is toxic to plants and animals, and it has no preventive effect — moss grows back quickly, often more vigorously. SOS Nettoyage uses professional biocide products that work in depth and offer a lasting preventive effect.
Can I have my terrace cleaned in winter?
Terrace cleaning is not recommended in winter in French-speaking Switzerland. Low temperatures (below 5°C) prevent treatment products from working properly, residual water can freeze and damage materials, and working conditions are unfavourable. The best period is spring (March to May), when temperatures rise and surfaces are sufficiently dry. SOS Nettoyage schedules its interventions during optimal periods.
Do you offer an annual terrace maintenance package?
Yes, SOS Nettoyage offers annual packages for terrace maintenance. A typical package includes a complete spring clean (cleaning + anti-moss treatment + protection) and a lighter autumn maintenance (leaf clearing, preventive anti-moss treatment). This package offers a preferential rate of 10 to 15% compared to one-off interventions, and guarantees an impeccable terrace throughout the year without you having to think about it.