Gaz's Glazing Blog

Why Your Window is Always Foggy and How to Resolve the Issue

by Arianna Griffin

Have you noticed that your double glazed window appears foggy and remains so, even after your most vigorous cleaning efforts?  If that describes your problem here's what is going on and more importantly, what you can do about it.

What Causes the "Fog"?

The fog is the result of condensation forming between the glass panels. This occurs because the surface temperature of the window glass is so much colder than the room temperature. When the colder air between the glass panes comes into contact with the warmer air in the room, it condenses and water droplets form.

A condensation problem inside double glazed windows is quite often a sign that there is a fault with the sealant between the glass and the window frame, allowing moisture to enter the cavity.

If this problem is left untreated, not only is the view from the window unsightly and foggy, but the moisture may continue to slide down onto the wall below encouraging further troubles in the form of black mould or wet rot.

Additionally, a damaged seal can also contribute to a substantial amount of heat loss from your home and cost you more in wasted energy.

What is the Best Option?

Fortunately, there are now some very effective repair techniques available and considerable expertise in the area of restoration of double glazed window units. Certainly, window repair is a far more economical solution than the alternative of finding the necessary funds for a completely new window.

Repairing the Seal - What to Expect

Most window repair companies will use techniques that involve:

  • drilling very small holes in the spacer bars between the glass panels.
  • injecting or pumping a drying agent to expel the moisture.
  • Cleaning the glass and moving marks and smears
  • Applying an anti-misting agent to prevent further moisture from building up.

The final re-sealing process will usually involve injecting a sealant material along the base and completely sealing the unit by closing up the holes that have been made. An alternative technique makes use of special vents that are inserted into each hole to allow air flow.

Naturally, if you decide to have your window repaired rather than opting for a complete replacement, you will need to research for a company with abundant experience in this specialized process as well as a first class reputation. Also for peace of mind look for one that offers the longest term guaranteeing their workmanship.