How to clean windows without streaks: the professional method, the right order and what it costs

Streaks, smears, water marks – even after an hour of cleaning. Almost everyone knows the problem. The good news: if you know how to clean windows without streaks, it is not a matter of luck or miracle products but of method, tools and order. In this guide we show how professional window cleaners work, which mistakes cause streaks, when it is worth calling in a professional and what window cleaning realistically costs in Vienna, Graz, Linz and Salzburg.

What does professional window cleaning involve?

Professional window cleaning covers far more than wiping the glass. A complete clean includes:

• Glass inside and out, including the hard-to-reach corners along the seals,
• Frames and sashes made of uPVC, wood or aluminium,
• Rebates – the areas you only see when the window is open, where dust, insects and soot collect,
• Window sills inside and out,
• on request, blinds, roller shutters, insect screens and conservatories.

Professionals also distinguish between routine cleaning, carried out at fixed intervals, and deep or post-construction cleaning, in which label residue, silicone, mortar splashes or paint are removed with specialist tools.

Why do windows get streaky in the first place?

Streaks almost always come down to one of these five causes:

1. Too much cleaning product: surfactant residue stays on the glass as a film and becomes visible when the light shines through.
2. Hard water: in many parts of Austria the tap water is high in limescale. If it dries on the pane, it leaves white marks.
3. Sun on the glass: the water evaporates faster than you can squeegee it off.
4. The wrong drying material: newspaper, kitchen roll or linting cotton cloths leave fibres behind and smear the dirt.
5. Dirty tools: a dirty or damaged rubber blade on the squeegee leaves lines.

Why clean windows regularly – and how often?

Clean windows let considerably more daylight into a room. That is not only pleasant; in offices it also saves on lighting costs and improves the working atmosphere. Then there is the question of preserving value: soot, pollen and acid rain settle on glass and seals, causing rubber seals to age faster.

How to clean windows without streaks: the professional method

The right tools

• Applicator (a window washer with a microfibre or blended-fibre sleeve) to apply the solution and loosen the dirt,
• Squeegee with a flawless rubber blade, ideally in a suitable width,
• Bucket of lukewarm water with a splash of glass cleaner or a few drops of washing-up liquid – nothing more,
• lint-free microfibre cloths for edges and frames,
• Glass scraper with a blade for stubborn residue – only ever used on wet glass,
• a separate cloth and a pH-neutral all-purpose cleaner for frames and rebates.

The order: top to bottom, clean to dirty

1. Prepare: clear the window sill, protect the floor with a towel, draw back the curtains.
2. Frames and rebates first: if you clean the glass first and the dusty frame afterwards, dirty water drips onto the clean pane. That is why rebates and frames come first.
3. Wet the glass: use the applicator to wet the entire surface, paying particular attention to the edges.
4. Squeegee: start at the top left and guide the squeegee in one continuous S-shaped movement (professionals call it “fanning”) or in straight strokes from top to bottom. Each stroke overlaps the previous one by a few centimetres. Wipe the rubber blade with a cloth after every stroke.
5. Finish the edges: remove the narrow wet strip along the edge with a dry, lint-free cloth.
6. Window sill last: this is where the water you have squeegeed off ends up – so it is cleaned last.
7. Check against the light: look at the glass from an angle and polish any small spots with a dry microfibre cloth.

Box-type double windows (Kastenfenster), common in Vienna’s older buildings, have four glass surfaces per window. Here you work from the outside in, so that dust from the gap between the panes does not land on inner surfaces you have already cleaned.

A word on technique: the first stroke matters most. Many professionals start by drawing the squeegee across the top edge of the pane to create a dry strip, then work downwards from there. That way the blade always starts on dry glass and no drips run back into the cleaned area. With a little practice, an average window takes only a few minutes per side.

Which products make sense?

For most windows, water with a very small amount of washing-up liquid or glass cleaner is enough. A dash of methylated spirit helps with greasy films in kitchens. A mild vinegar solution works against limescale marks – but only on the glass, not on natural stone window sills, anodised aluminium or wooden frames. For large glass areas, professionals increasingly rely on pure water technology: demineralised water is applied with a brush on telescopic poles and dries without residue, because it no longer contains any minerals.

Caring for frames according to material

• uPVC frames: neutral cleaner and a soft cloth. No abrasive cleaners and no solvents – they make the surface dull and porous, and dirt then sticks to it more quickly.
• Wooden frames: wipe only with a barely damp cloth and remove standing water immediately. Painted frames can handle a mild soap solution; oiled frames occasionally need a care oil.
• Aluminium frames: clean with pH-neutral products. Anodised surfaces are sensitive to acidic and strongly alkaline products.
• Seals: wipe with clean water and treat with a rubber care product once or twice a year so that they stay supple and seal tightly.

Special cases: limescale, stickers and building dirt

Limescale marks on glass can be dissolved with diluted citric acid or a mild vinegar solution; then rinse thoroughly with clean water. Label residue and adhesive are softened with soapy water and removed with the glass scraper held at a shallow angle – always on wet glass. Mortar, silicone and paint splashes after building work call for a dedicated post-construction clean: experience is essential here, because coated low-emissivity glass and toughened safety glass can be scratched permanently by the wrong tool. Many glass manufacturers even rule out blades on certain types of glass – if in doubt, check the manufacturer’s instructions first.

Fee from Bling Bling: My professional tip: wipe the rubber blade of your squeegee after every single stroke. It takes a second, and it is the most common difference between streaky windows and genuinely clear ones.

You make the mess – we make it go away

Safety: when should window cleaning be left to professionals?

Every year in Austria, people are injured falling from ladders and window sills at home. The Austrian Road Safety Board (KFV), which also campaigns on home safety, regularly highlights the risk of falls in the household (KFV). Never stand on window sills or wobbly chairs, and do not lean out of the window. At the latest when windows can only be reached from outside, or for glass roofs, conservatories or façades above ground-floor level, a specialist company with an aerial work platform, telescopic poles or rope access is the safer choice. For commercial work at height, Austrian occupational health and safety rules on fall protection apply.

How much does professional window cleaning cost? Price guidelines for 2026

Depending on the property, billing is per window sash, per square metre of glass or by the hour. The following guideline prices are net, plus VAT, for normally soiled windows including frames; box-type windows in older buildings, windows with glazing bars and work at height take more effort.

Depending on location, travel costs are added, and equipment costs for work at height. You receive a binding fixed price after sending photos or a short site visit. Find out more about what we offer on our window cleaning in Vienna and glass cleaning in Vienna pages.

Two factors influence the price more than most people expect: accessibility and condition. Windows that open fully and can be reached safely from inside are quick to clean. Fixed panes, skylights and windows behind furniture or plants take noticeably longer, as do windows that have not been cleaned for several years and are covered in a hardened layer of soot and limescale. Regular cleaning therefore tends to be cheaper per visit than an occasional big clean.

How working with us works

For regular window cleaning in an office or shop, we set fixed intervals and come at times that do not disrupt your business – early in the morning, in the evening or at the weekend. Our customers rate us 4,8 stars on Google from 200 reviews.

Common mistakes: why people fail to clean windows without streaks

• Cleaning in bright sunshine: the water dries before it is squeegeed off. Morning, evening or an overcast day is better.
• Too much cleaner: more product means more residue. A few drops per bucket are enough.
• Using newspaper: modern printing inks rub off and leave smears on frames and seals.
• Cleaning the glass before the frame: dirty water from the frame runs down the clean pane.
• Using a glass scraper on dry glass: this causes scratches, especially on safety and coated glass.
• Cream cleaners or rough sponges: they permanently scratch glass and coatings.
• Vinegar on natural stone window sills: it etches marble and limestone.
• Risky climbing: no streak-free window is worth a fall.

Checklist: how to clean windows without streaks

• Overcast day or shady side of the building chosen
• Window sill cleared, floor protected
• Frames, rebates and seals cleaned first
• Lukewarm water, only a few drops of cleaner
• Glass fully wetted, corners not forgotten
• Squeegee used from top to bottom, strokes overlapping
• Rubber blade wiped after every stroke
• Edges finished with a dry microfibre cloth
• Window sill cleaned last
• Checked against the light, remaining spots polished
• Box-type windows: worked from the outside in

Frequently asked questions