Repair plastic windows - is this possible?

After break-ins or after unfortunate drilling actions on the window frame but also with other damages, a repair of plastic windows is often possible. How it works, how it is done professionally, and what to look for is explained here.

Possible damage

  • forced entry
  • wells
  • Cracks and crevices
  • Other damages

forced entry

Break-in marks on plastic windows can always be repaired well if the hardware is still intact. That's not always the case.

To repair damage to the frame, you can use a polyester putty. For deeper damage, we recommend foaming with PU foam beforehand. Apply fine putty layer by layer and smooth it out carefully.

Then sand with ever finer sandpaper, start with very fine grain (about 600). Keep the grain finer until a completely smooth surface is created.

An injection with white silicone is also possible, but usually does not bring very nice results.


Boreholes in the window frame must always be filled with PU foam first. Thereafter, the surface of the borehole can be closed and ground as before with polyester fine putty.

Cracks and crevices

Cracks and crevices can usually be repaired quite well with professional repair kits. Fenoplast repair kits are available in various RAL colors.

For most common frame manufacturers, Fenoplast offers specially matched sets that match the exact color of the frame, such as RAL 90 10 or RAL 90 16. The repaired damage is virtually invisible after repair.

Other damages

Damage to the fittings or hinges you can usually repair even more. Only specialist companies can help here. Otherwise, the window must be replaced.

Even damage to the window glass - such as after a burglary - can sometimes be repaired. In some cases, however, a window exchange is inevitable.

Repair by specialized companies

There are specialist companies that specialize in the repair of damaged windows. Not all types of damage and not all window types can be repaired.

After a break-in, a specialist company can also settle directly with the applicable insurance. Quick repairs and short-term repair of damage are possible in many cases.

Tips & Tricks

To protect against break-ins and thus avoid damage to the windows, you can retrofit burglary protection in almost all plastic windows.

Video Board: How to Repair Damage to an Extruded White UPVC Profile