Windscreen Delamination: Cloudy or Milky Edges Explained

Windscreen Delamination: Cloudy or Milky Edges Explained

If the edges of your windscreen have gone cloudy, milky or bubbly, the layers of glass may be separating. This is called delamination. It is less common than chips and cracks, but it is worth understanding because it affects how the windscreen performs.

How a Windscreen Is Made

A windscreen is laminated glass: two layers of glass bonded to a clear plastic interlayer in between, usually polyvinyl butyral (PVB). That interlayer is what holds the glass together when it breaks. Our article on laminated vs toughened car glass explains why windscreens are made this way.

What Delamination Looks Like

• A milky, cloudy or hazy band, usually starting at the edge
• Small bubbles or a “rainbow” or oily look between the layers
• A discoloured or yellowish patch that does not wipe off from either side
• Marks that slowly creep in from the edge over months

If you can clean it off from the inside or outside, it is not delamination — it is on the surface.

What Causes It

Moisture getting into the edge

The interlayer can absorb moisture where it is exposed at the edge of the glass. Over time this can weaken the bond and cause cloudiness. Leaks around the windscreen make this more likely — see what causes windscreen seal failure.

Age, heat and UV

Years of heat cycles and sunlight can gradually affect the interlayer, especially on older vehicles.

Damage or a flaw at the edge

A chip or crack at the edge, or a manufacturing flaw, can give moisture a way in.

Some cleaning products

Harsh solvents worked into the edge of the glass over time are best avoided. A pH-neutral glass cleaner is the safe choice — see how to clean your windscreen without scratching it.

Is Delamination a Safety Problem?

Small delamination at the very edge, hidden under the black frit band, may not affect your view. But the interlayer is what holds a laminated windscreen together, so separation is a sign the glass is not performing as designed in that area. If it reaches the driver’s line of sight, affects a camera or sensor area, or keeps spreading, the windscreen should be replaced.

Can Delamination Be Repaired?

No. Resin repair is for chips and short cracks; it cannot rebond the layers of a windscreen. The fix for delamination is a replacement windscreen. Windscreen replacement with Aussie AutoGlass starts from $330, depending on your vehicle.

If your windscreen is fairly new and showing delamination, check your windscreen warranty, as early delamination can point to a fault in the glass.

Frequently Asked Questions

Is delamination the same as fogging?

No. Fogging is condensation on the surface and wipes off or clears with the demister. Delamination is between the layers and cannot be wiped away.

Will delamination fail a roadworthy inspection?

If it affects the driver’s view, it can. Our article on whether a damaged windscreen can fail rego covers how inspectors look at windscreen damage.

Can side windows delaminate?

Most side and rear windows are toughened glass with no interlayer, so they do not delaminate. Some vehicles have laminated side glass, which can.

How fast does delamination spread?

Usually slowly, over months or years, but it varies. Keep an eye on it and have it checked if it moves towards your view.

Seeing cloudy patches in your windscreen? Aussie AutoGlass is a mobile service across greater Sydney — we come to your home or workplace. Book an appointment or call 0405 412 951.