You want to solve a broken window quickly. Sometimes it is a small crack, sometimes an asterisk, a broken glass plate or a leaky insulating window. The question then is: can you still repair the glass, or does the window need to be replaced?

The short rule is: A broken window in residential glass is usually replaced instead of repaired. Scratches can sometimes be polished, but cracks, breaks, leaking double glazing and damaged safety glass usually need to be replaced. In this article we explain when glass replacement is necessary, when repairs are still possible and what you should pay attention to with single glazing, double glazing, HR++ glazing, safety glass and shower glass.

What do we mean by a broken window?

A broken window can mean different things. Not all damage is the same. Common glass damage:

  • Crack in the glass
  • Asterisk or dimple
  • Completely broken window
  • Tear from the edge
  • Leaky double glazing
  • Condensation between glass sheets
  • Scratch in the glass
  • Damaged glass edge
  • Broken shower wall
  • Broken mirror
  • Glass breakage in door
  • Damage to safety glass

The right solution depends on the type of damage and the type of glass.

Can you fix a broken window?

In most cases not. A window in a home, door, shower wall or furniture is usually replaced if there is a crack or break. Glass loses its strength due to a crack and can crack further.

Repair is sometimes possible for:

  • Very light scratches
  • Superficial cleaning scratches
  • Minor damage out of sight
  • Temporary emergency seal
  • Some car windows, but that is a different type of application

Replacement is usually necessary for:

  • Crack
  • Tear
  • Asterisk in home glass
  • Leaky double glazing
  • Condensation between glass sheets
  • Broken safety glass
  • Damaged glass edge
  • Glass in door, balustrade or shower wall

You cannot reliably "glue" a crack in glass so that it is as new and safe again.

Why is home glass usually replaced?

Glass is a hard and brittle material. If a crack occurs, the tension in the glass is disturbed. The crack can become larger due to temperature differences, wind pressure, movement or a small tap. Replacement is often necessary because:

  • The window is weakened
  • The crack can tear through
  • Insulation value can be lost
  • Safety decreases
  • Moisture can penetrate
  • Repair remains visible
  • The damage cannot be structurally and reliably repaired

A broken window is not just about appearance, but also about safety and performance.

Rule of thumb: You do not repair a crack or break in home glass, you replace it. Only very light, superficial scratches can sometimes be polished.

Image: close-up of a crack running from the glass edge into the glass

Crack in glass: replace or repair?

A crack in a home window usually needs to be replaced. The crack can become larger and the glass is no longer reliable. Replace glass at:

  • Crack from the edge
  • Crack in the middle of the glass
  • Multiple cracks
  • Crack in insulating glass
  • Crack in safety glass
  • Crack in door or window
  • Cracks due to temperature difference
  • Cracks after bump or impact

Removing a crack with glue is not a sustainable solution. It remains visible and the glass remains weakened. Also read: crack in double glazing.

Asterisk in window glass

An asterisk on car windows can sometimes be repaired. This usually works differently with residential glass. An asterisk in window glass may indicate impact damage and may crack later. For residential glass, replacement is usually wiser, especially if:

  • The star is in insulating glass
  • The damage is visible
  • There's a crack running out of it
  • The glass is under tension
  • The window is large
  • The glass is part of a door or facade

An asterisk in a residential window is usually not a good candidate for a neat repair.

Broken single glass

Single glazing is relatively easy to replace. It is thinner than insulating glass and is often found in older wooden frames with glazing beads or putty. If you have broken single glazing you can choose:

If you do have to replace, it is smart to see whether better insulating glass is possible. Replacing single glazing is not always the best choice. View the options at replace single glass.

Broken double glazing

Double glazing consists of two panes of glass with a cavity between them. If one sheet of glass breaks, the entire glass package usually needs to be replaced. So you don't just replace the loose broken layer. This is because double glazing is made as a closed unit. The spacer and edge seal together form the insulation package.

Replace double glazing for:

  • Crack in one of the glass sheets
  • Condensation between the windows
  • Leakage from the cavity
  • Damaged edge seal
  • Visible haze between glass
  • Rupture due to tension

When replacing, you can often switch to HR++ glass if the frame is suitable for it. You can read more about this at replacing double glazing.

Leaky double glazing

A leaky window is also a broken window, even if the glass is not broken. If double glazing is leaking, the edge seal is broken. Moisture enters the cavity, causing condensation or haze between the glass sheets. You can recognize leaking double glazing by:

  • Condensation between the glass sheets
  • White haze in the cavity
  • Stains that you cannot polish away
  • Less clear vision
  • Sometimes chalky deposits inside
  • Reduced insulation

You cannot properly clean or dry leaky double glazing. The solution is usually: replacing the window. See recognizing and replacing leaking double glazing.

Broken HR++ glass

HR++ glass is also insulating glass. If HR++ glass breaks or leaks, the entire glass package must be replaced. Please note with HR++ glass:

  • Check the thickness of the existing package
  • Look at cavity width
  • Check the frame and glazing beads
  • Pay attention to coating position
  • If necessary, select HR++ or better again
  • Check ventilation grille if present

When replacing, it is important that the new window fits into the existing frame and provides the same or better performance. More about this glass type: HR++ glass, what is it?.

Broken triple glass

Triple glass consists of three glass sheets and two cavities. In the event of damage, the entire package will also be replaced. Triple glass is:

  • Fatter
  • Heavier
  • Insulating
  • Often more expensive
  • Not always easy to replace
  • Depending on frame and glazing beads

In case of broken triple glass, weight, thickness and dimensions must be carefully examined. The frame and fittings must remain suitable.

Broken safety glass

Safety glass can be toughened or laminated. You must be extra careful in case of damage.

Tempered glass

Toughened glass breaks into small grains when broken. If it breaks, the window is immediately broken and must be replaced. Tempered glass is used for:

  • Shower walls
  • Glass doors
  • Table tops
  • Kitchen back walls
  • Some side lights
  • Windshields

Laminated glass

Laminated glass will stick to the foil if broken. It can therefore partly remain in place, but it is damaged and usually needs to be replaced. Laminated glass is used for:

  • Balustrades
  • Roof glass
  • Safety applications
  • Fall protection
  • Injury-resistant glazing

With safety glass, the new window must be able to provide the same safety function. Are you unsure which type you need? Read tempered or laminated glass.

Broken shower enclosure

A shower enclosure is often made of tempered safety glass. When tempered glass breaks, it shatters into small pieces. Repair is then not possible. Replace shower glass for:

  • Crack
  • Damaged corner
  • Chip on the edge
  • Glass breakage
  • Loose fittings
  • Deep scratches
  • Damage around holes or hinges

Please note: Tempered glass cannot be cut, drilled or modified afterwards. All holes and recesses must be included in the dimensions in advance. See custom shower enclosure: what to look out for.

Broken glass door

Glass doors are usually made of tempered glass or laminated glass. In the event of damage, you must look carefully at safety and fittings. Replace a glass door for:

  • Crack
  • Damaged edge
  • Damage around hinge hole
  • Damage around lock hole
  • Broken corner
  • Deep impact damage
  • Glass that no longer hangs securely

Because doors move and are loaded, damaged glass is extra risky. More about this: custom glass door.

Broken glass table top

A glass table top can become scratched, cracked or edge damaged. Light scratches can sometimes be polished, but cracks and deep damage cannot. Replacement is wise for:

  • Crack in table top
  • Corner broken off
  • Deep chip on edge
  • Damage at support point
  • Damage in tempered glass
  • Large scratch in the center of view
  • Glass is no longer stable

For a new table top, you can choose tempered glass, laminated glass or thicker glass with a neat edge finish. See custom glass table top.

Broken mirror

A mirror is difficult to repair. If the glass breaks or the reflective layer is damaged, the mirror usually needs to be replaced. Replace a mirror for:

  • Crack
  • Black spots behind the glass
  • Damaged reflective layer
  • Broken corner
  • Moisture behind the mirror
  • Deep scratch in visible area

Black edges or spots are often caused by damage to the mirror coating. You usually can't repair that properly. More about customization: custom mirror: what to look out for.

Emergency solution for broken window

Sometimes you have to make a broken window temporarily safe until replacement is possible. Temporary measures:

  • Do not touch broken glass with bare hands
  • Keep children and pets away
  • Temporarily cover any cracks with strong tape
  • Cover the opening with sheet material or foil
  • Remove loose shards carefully
  • Wear gloves and safety glasses
  • Prevent rain impact
  • Call a glazier in case of major damage

An emergency solution is temporary. The glass must then be replaced.

When is urgency necessary?

Urgency is wise when the broken window causes danger or nuisance. Urgently needed for:

  • Large opening to the outside
  • Burglary damage
  • Glass shards on the floor
  • Broken door or facade
  • Rain or wind comes in
  • Window on ground floor is open
  • Safety glass on the balustrade or roof is damaged
  • House can no longer be locked

In case of minor damage without immediate danger, you can often measure and order a new window.

Can glass break for no apparent reason?

Yes, glass can sometimes break without immediately seeing a clear cause. There is often tension, edge damage or temperature difference. Possible causes:

  • Thermal fracture
  • Damaged glass edge
  • Wrongly placed window
  • Tension in frame
  • Glass is stuck
  • Strong wind load
  • Settlement of building
  • Impact that arose earlier
  • Wrongly placed glass blocks
  • Too little space around glass

A crack often starts from the edge. This may indicate tension or edge damage.

Thermal fracture

Thermal fracture is caused by temperature differences in the glass. Part of the window becomes warm, while another part remains cold. This creates tensions. Causes of thermal fracture:

  • Partial shade
  • Dark foil on glass
  • Furniture close to window
  • Cushions against glass
  • Heating directly at the glass
  • Sun on cold window
  • Glass with existing edge damage

You often see thermal breakage as a crack that starts from the glass edge.

Damage due to incorrect placement

Glass must be installed without tension. If a window gets stuck or is incorrectly supported, it can break later. Installation errors:

  • Too little play
  • Wrong glass cubes
  • Glass rests on hard surface
  • Crooked frame
  • Glazing beads press too hard
  • Sealant or band applied incorrectly
  • Edge damaged during installation

If glass breaks recur, you should not only replace the window, but also have the cause investigated.

Do you have to put the same glass back?

Not always. A broken window is often a good time to improve. You can consider:

  • Replace single glass with HR++ glass
  • Replace old double glazing with HR++
  • Apply safety glass where necessary
  • Figured glass replaced by modern figured glass
  • Choose sound-resistant glass
  • Apply sun-resistant glass
  • Use vacuum glass in old window frames
  • Add or replace ventilation grille

Please note whether the existing frame is suitable for the new glass structure.

Measuring a broken window

Before replacement, the window must be measured properly. With insulating glass, not only width and height are important, but also thickness. Important when measuring:

  • Width
  • Height
  • Total glass thickness
  • Cavity width for insulating glass
  • Type of glass
  • With or without coating
  • Safety glass or not
  • Ventilation grille
  • Figure glass direction
  • Edge finishing
  • Holes or recesses

Don't just measure the visible glass. The window partially fits into the rebate of the frame. Follow the step-by-step plan in measure glass.

Image: someone measures the width of a window in the frame with a tape measure at

Who pays for a broken window?

That depends on the situation and insurance. In the event of damage due to storm, burglary or accident, glass insurance or home insurance can sometimes provide cover. In rental properties it depends on the rental contract and the cause. Check:

  • Glass insurance
  • Building insurance
  • Contents insurance
  • Rental contract
  • HOA rules
  • Cause of damage
  • Own risk
  • Obligation to report to landlord or insurer

Take photos of the damage before you clean it up or have it replaced, especially in the event of a burglary or storm damage.

Common mistakes with a broken window

  1. Try to patch crack — that does not reliably restore the strength of the glass.
  2. Wait too long — a crack can become larger and more dangerous.
  3. Just look at the glass — sometimes the cause is the frame, placement or tension.
  4. Replace incorrect glass — for safety applications, the correct glass must be replaced.
  5. Do not check thickness — new glass must fit the frame, glazing beads and rubbers.
  6. Try to clean leaking double glazing — moisture between glass sheets is in the cavity and is not accessible.
  7. Removing shards without protection — always wear gloves and shoes.

Selection aid: repair or replace?

Damage Best choice
Light scratch Sometimes polishing
Deep scratch Replace often
Crack in glass Replace
Asterisk in home glass Usually replaced
Broken single glass Replace
Broken double glazing Replace entire glass package
Condensation between double glazing Replace window
Broken HR++ glass Replace glass package
Broken tempered glass Replace
Cracked laminated glass Replace
Broken mirror coating Replace mirror
Temporary opening Emergency seal, then replace

Are you unsure whether a scratch can still be repaired? Read repair scratch in glass.

Checklist for a broken window

Check these points:

  • Is it a scratch, crack or break?
  • Is there immediate danger?
  • Are there any loose shards?
  • Is it single glazing, double glazing or HR++?
  • Is there moisture between glass sheets?
  • Is it safety glass?
  • Is the damage on the edge?
  • Is there damage to the frame or glazing beads?
  • Is there a burglary or storm?
  • Should insurance be involved?
  • Should the same glass be returned?
  • Is better insulating glass possible?
  • Is professional installation necessary?
  • Does it need to be temporarily sealed?

Conclusion

In most cases, a broken window is replaced instead of repaired. You can sometimes polish minor scratches, but cracks, fractures, leaking double glazing and damaged safety glass cannot usually be repaired reliably. Single glazing can often be replaced relatively easily. With double glazing, HR++ glazing and triple glazing, you usually replace the complete glass package. The correct glass structure is extra important for safety glass, shower walls, doors and balustrades.

Do not use a broken window for too long. Make the situation temporarily safe, check the type of glass and have the window properly measured. A broken window is a good time to see whether better insulating, safer or sound-resistant glass is a smart upgrade.

Read more? Continue with crack in double glazing, recognizing and replacing leaking double glazing or measuring glass. Ready to order? Create your window using custom glass, view the options for shower and bath, or contact contact for personal advice.