Mold on the window putty

It is a commonly seen image: black mold on white window putty, which disfigures the beautiful old wooden windows. What you can do about it, and where possible causes lie, you can read here in detail.

Mold on the putty

Window putty is a material that basically provides mold with a good breeding ground. Classic window putty consists mainly of linseed oil and whiting. Mold keeps it up very well.

This not only the wooden window frame, but also the putty is a preferred infestation site for the mold fungus. A distance is often difficult.

Above all, it is important to determine the cause of the mold infestation. Mildew always needs moisture to multiply and spread.

The most important measure in the investigation of causes is thus to seek the cause of a permanent moisture penetration in the area of ​​the cement and possibly also of the window frame. It can be:

  • a thermal bridge in the area of ​​the glass pane edges which leads to the formation of condensation (often also visible to the pane)
  • leaky windows or poor glazing
  • warped and thus leaking wooden frame
  • Damage to the wooden frame
  • too low U-value of the wooden windows compared to the wall insulation (rare)

The risk of thermal bridge formation is particularly great in old wooden windows. They are - unlike plastic windows not completely sealed. This causes a constant exchange of air with the environment.

At such a location, if the airflow is too great, and the cold air cools too quickly, condensation may form, which then collects on the disk or leaks. The constant penetration of the putty then leads to mold growth.

Remedy of infestation

Removing mold with a brush and a scrubber alone is not sufficient and dangerous. The infested material must always be completely replaced.

Bringing a removal of the old cement and a new kitten and a sealing of the window frame not the desired success, usually remains only the replacement of the windows.

Tips & Tricks

When replacing the putty and removing it, make sure that old putties may contain dangerous asbestos!

Video Board: How To Remove Mold From A Window Sill (Without Harmful Chemicals)