Scratched Window Glass and Whether It Can Be Repaired

In most cases, surface damage to window, door or conservatory glass can be repaired by a glass repair specialist. They remove a minimal amount of the glass surface to fix the defect without impairing the visual quality. A very deep scratch or damage to a coated surface means you will need to replace the glass instead.

Can scratches be removed from window glass?

Surface damage can impair the visual quality, performance and appearance of your windows. Repairing this damage is a viable alternative to replacing the whole pane. In many cases, it can be repaired safely and effectively by a glass repair specialist.

You should talk to a specialist who will survey the damage and give you a quote for the work. A quote is a fixed price, while an estimate is not. If you agree to a repair service on the doorstep, by phone or online, it normally carries a 14-day cooling-off period.

What causes scratches and surface damage

Glass is a tough material but it remains vulnerable to surface damage from several common sources. Scratches are often caused by hard or sharp objects applied to the glass. This can happen accidentally or maliciously. If these scratches are left untreated, they may result in the glass failing.

Graffiti is another common cause of surface damage on commercial and domestic windows. The glass can be etched intentionally, or marked with paint or indelible ink. Removing graffiti the wrong way can also damage the glass.

Airborne contamination builds up over time and affects the glass. Organic matter such as bird droppings and inorganic matter such as road film sit on the surface. These may have an abrasive effect and can reduce the visual quality of the window.

Building contamination, such as run-off from building work or sealant leakage, can also damage the surface of the glass.

How professional glass repair works

A glass repair specialist should survey the damage first to check whether repair is practical or the damage is too severe. If a scratch is very deep, the specialist should advise replacement at this stage.

The repair process involves removing a minimal amount of the glass surface. This is done carefully to rectify the defect without impairing the visual quality of the window. When the treatment is finished, there should be no visible distortion in the glass.

In exceptional circumstances, an unacceptable level of distortion may only become evident during or after the treatment. If this happens, the specialist will advise that replacement is necessary. This is rare, but it is a risk you should discuss before the work begins.

When replacing the glass makes more sense

Repair is not always the best route for every window. In many cases, replacing the damaged glass may be the most economical option.

However, replacement is sometimes far more expensive than repair. A large landing window is a typical example. In these situations, repair can be a time saving and cost effective solution.

You should also consider the environment when making your choice. The environmental impact of repairing a pane is significantly less than the impact of manufacturing and fitting a replacement.

The table below compares the options of repairing and replacing window glass based on glazing industry guidance.

A specialist's survey will show which of these applies to your glass.

Toughened glass and coated glass

You might worry that repairing a scratch will make your window unsafe. The glazing industry trade body tested scratched glass to check this. Its Glass Repair Group found that removing surface damage does not have a detrimental effect on the failure characteristics of toughened safety glass.

Almost all types of glass can be treated safely by a specialist. There is one major exception you need to know about. If you have coated glass and the coated surface has been damaged, repair is not recommended. You will need to arrange a replacement pane instead.

How to avoid scratching glass when you clean

Careless cleaning can scratch glass. Window manufacturers publish care guidance to help you protect the pane, and these are the main points.

• Never try to clean dirt off the pane without applying water first.
• Wash windows with a soft cloth and warm soapy water.
• Use a squeegee with a soft blade to leave clear glass.
• Keep all sharp or abrasive objects including jewellery away from the glass.
• Never use a scouring pad, wire wool or a sponge with a scouring surface.
• Do not use cleaning products containing abrasive particles or chemical products on the pane.
• Protect the pane with a clean plastic sheet if building work is taking place nearby.

Professional window cleaners follow specific methods to clean safely. Traditional cleaning uses an applicator, a squeegee and a cloth. Many cleaners now work from the ground with poles to avoid ladders. Industry guidance hosted by the Health and Safety Executive states that a water-fed pole is a telescopic pole fitted with a brush and a means of delivering purified water.

The purified water is an integral part of the cleaning process. The glass is scrubbed, rinsed and left wet. Because the minerals have been filtered out, the water is meant to dry without marks. A first pole clean can leave some spotting until old residue has been rinsed out. You can learn more about this method in our guide to water-fed pole window cleaning.

Rules and protections in the window cleaning trade

If you decide to hire a window cleaner to maintain your glass, it helps to understand the rules they follow. Ladders are not banned in the UK. The Health and Safety Executive says ladders can be a sensible option for low risk, short duration work, including domestic window cleaning on lower floors.

The Work at Height Regulations 2005 require work at height to be properly planned, done by competent people and avoided where reasonably practicable. This is why many cleaners now work from the ground with poles. The law asks for competence, not a formal qualification.

In Scotland most councils require window cleaners to hold a window cleaner's licence under the Civic Government (Scotland) Act 1982. These licence holders carry identification. Requirements vary by council, but window cleaners elsewhere in the UK are not licensed in this way.

Employers' liability insurance is compulsory for a window cleaning business with employees. Industry guidance produced with the Health and Safety Executive also says water-fed poles must not be used near overhead power lines. You should always point out any overhead cable to your cleaner before they start work.

If you think a tradesperson scratched your glass

Builders, decorators and other trades often work close to your glass. If you think a tradesperson has caused surface damage, you are protected by the Consumer Rights Act 2015. A trader must carry out a service with reasonable care and skill.

If they fail to do this, you can ask them to put the damage right. If they cannot or will not fix the problem, you have the right to ask for a partial or full refund. Any agreed refund amount should be paid within 14 days.

Follow these steps to raise the issue politely and clearly:

1. Take photos of the scratched glass as evidence of the problem.
2. Put your complaint in writing to the trader so there is a clear record.
3. Explain that the work was not done with reasonable care and skill.
4. Ask them to arrange a repair or provide a refund.
5. Ask if they hold a current public liability insurance certificate.

Public liability insurance is not a legal requirement for most UK businesses. However, it is the cover that pays compensation claims for accidental injury to the public and for damage to other people's property. A reliable tradesperson should hold this insurance and be willing to show you their certificate.

Membership of the Federation of Window Cleaners is another good sign. This non-profit trade body was established in 1947 and promotes a code of practice, a safety accreditation scheme and training for its members. Membership is voluntary, so treat it as one good sign among several.

Warranties on double glazing

If your windows are relatively new, you should check the paperwork before paying for a repair. Double glazing often comes with a warranty of 10 or 20 years. Some installation companies even give a lifetime guarantee on their products.

You need to read the fine print to see what your warranty covers and until when. Some warranties cover only certain parts of the window or apply for different periods.

After a warranty ends, you are still protected by the Consumer Rights Act. To make a claim under this law, you have to show the fault came from a defect in the product or the installation. You cannot claim if the damage came from normal wear and tear or something you did to the glass.

Questions to ask a glass repair specialist

When you contact a specialist, you need to agree on exactly what they will do. Ask these questions to make sure you get a fair and clear service:

• Will you survey the damage before you start work?
• Can you confirm whether my glass is toughened or coated?
• What happens if distortion appears during the treatment?
• Will you provide a fixed written quote rather than an estimate?
• Do you hold a current public liability insurance certificate?

Common questions

Can you guarantee the removal of scratches on glass?

No professional can guarantee a repair without surveying the damage first. A specialist needs to check the pane to see if the scratch is too deep to fix. If the damage is too severe, they will advise you to replace the glass instead of attempting a repair.

Does scratch removal on glass weaken the window?

Repair involves removing a minimal amount of the glass surface to rectify the defect. The glazing industry trade body tested this process on scratched glass. They found that removing surface damage does not have a detrimental effect on the failure characteristics of toughened safety glass.

Should I try to polish out a scratch myself?

Window manufacturers strongly advise against using abrasive particles, chemical products, scouring pads or wire wool on glass. Applying these to a scratch can easily make the surface damage much worse. It is much safer to ask a professional glass repair specialist to survey the pane.

Does a water-fed pole scratch glass?

A water-fed pole is a telescopic pole fitted with a brush, and purified water is an integral part of the process. The glass is kept wet while it is scrubbed and rinsed, in line with care guidance that says never to clean dirt off a pane without applying water first.

Next steps

If you have scratched glass and want to sort it out, follow this checklist to make a good decision:

• Take clear photos of the surface damage in good daylight.
• Check your double glazing warranty to see what it covers and until when.
• Contact a glass repair specialist to ask for an initial survey.
• Ask for a fixed written quote for the repair.
• Compare the repair quote against the cost of replacing the damaged pane.

Regular careful cleaning helps to stop airborne contamination and dirt from building up on your windows. If you want to leave the job to a professional who has the right equipment, you can find a window cleaner near you to keep your glass, frames and sills in good condition.