How to Clean Windows After Renovation Work

After building work a window usually carries everything at once: leftover protective film, strips of tape, spatters of primer and paint, plaster dust in the drainage slots. Each of those comes off its own way, and the order matters — starting with the blade means grinding abrasive dust across the glass and scratching it.

What you need

• Washing-up liquid — 1 teaspoon per 5 litres of water
• Vegetable oil or WD-40 — for tape adhesive
• Isopropyl alcohol — for adhesive residue on glass
• Paint solvent — for glass only, never the frame

• A glass scraper with a blade
• A plastic spatula
• Microfibre cloths, two
• An old toothbrush for the drainage slots

Time: 45 minutes per window.

Step by step

1. Wash the dust off. Plenty of water with detergent first: construction dust is abrasive and any mechanical work over it scratches glass.
2. Peel the film. Pull at an acute angle to the glass, slowly. Warm dried-out film with a hairdryer on a medium setting.
3. Dissolve the adhesive. Oil or WD-40 on a cloth laid over the tape mark for five minutes, then lift with the plastic spatula.
4. Take the paint off with the blade. Only on wet glass, at 30 degrees, working away from you, without pressure.
5. Clear the drainage slots. The openings in the bottom of the frame, with a toothbrush; blocked with filler, they cause condensation inside the unit.
6. Wash it properly. Detergent solution, squeegee, dry microfibre to polish.

Method 2 — frame and reveals

A plastic frame after building work is often covered with a thin haze of primer that looks like clouding. It comes off with soapy water and dwell time, sometimes in two passes. A melamine sponge is used carefully here and only on white frames: on wood-effect laminate it takes the pattern off.

Method 3 — what not to remove

The silicone bead around the sealed unit is a structural element, not dirt: catch it with a blade and the window starts letting water in. The factory marking in the corner of the pane stays too — it is inside the glass, not on it. Expanding foam along the frame edge is trimmed flush with a knife and covered with a trim strip, not washed away.

What to avoid

• A blade on dry glass. Dust under the edge acts as sandpaper and the scratches are permanent.
• Solvent on a plastic frame. Acetone eats PVC in seconds and leaves a matt patch.
• A wire brush on the seal. The rubber tears and the window stops holding heat.
• Cleaning windows before the dirty work is finished. After the walls are sanded it all has to be repeated.

When this stops being window cleaning

If the construction dust has to come off the whole flat as well, that is a different service with a different basis of pricing. Post-renovation cleaning is priced by area — UAH 150 per square metre with a minimum order of 3,000 — and covers dust in the joints, mortar on the floor and washing the floors in several passes. Windows are then a separate item at UAH 450 instead of the usual 320, because film, tape and paint come off by hand.

Details are on the post-renovation cleaning page.

When to call a cleaner

One or two windows after cosmetic work are realistic to do yourself in an hour. A flat after a full refurbishment is another matter: six to eight windows, each with its own mix of soiling, and the job stretches across a day with the risk of scratching the glass on the last one. A window after building work costs UAH 450 and is almost always taken as part of post-renovation cleaning. Price it in the order form.

Frequently asked questions

How do I get paint off glass?

With a blade on wet glass at 30 degrees. Solvent only on the glass and never on the frame.

How do I remove tape marks?

Oil or WD-40 with five minutes of dwell time, then a plastic spatula and alcohol.

Why do windows cost more after renovation?

UAH 450 instead of 320: film, tape and paint come off by hand and each window takes twice as long.