What are steamy windows?

Double glazed units are made up of several components that form a complete sealed unit. A spacer bar, usually filled with a desiccant to absorb moisture, is sandwiched between two panes of glass. The sealant is then applied around the edges to form a seal.

When eventually the sealant fails, and the desiccant has absorbed its maximum amount of water, moisture is able to find its way into the unit. When the temperature changes from cold to warm and back again the moisture appears inside the glass unit and causes the “Steamy window” effect.

Unfortunately once this has happened it will not simply go away. It may disappear for a short time, but will then reappear and over time this will leave dirty water marks on the internal surface.

As well as looking unsightly, once the seal has been broken your windows will no longer be as efficient as they were. Cold air can now enter the cavity between the panes, thus reducing the temperature of the internal pane. At this stage if your units had Argon gas inside, this will now all have escaped.

 What causes the sealant to fail?

General age plus wear and tear is the most common reason for failure. Continuous changes in temperature causes the glass units to expand in warmth and contract in the cold, and over time this can loosen and damage the seals. However poor drainage at the bottom of the frames can also speed up the process. If the units are sitting in a pool of water when you remove the beads this is a sure sign of poor drainage.

Can my steamy windows be repaired?

Occasionally a glass unit will fail because of poor production methods. It this is the case it should be covered by your installers guarantee if it is within the specified time period.

Rather than trying to repair a steamy unit, it is usually easier and more cost effective to replace the whole unit. Your double glazed unit can easily be removed from your window by a double glazing installer, and a new sealed unit fitted in its place. There is no need to replace the whole window. However, you may find that if all of the glass units need replacing, and the window is quite old, it would be worth considering replacing the whole window for a new one.  The double glazed windows of today are miles more efficient than those of 20 or even 10 years ago. Replacing the window for an A+2 rated frame will also have the added benefit of giving a noticeable improvement in room temperature.

Don’t just put up with steamy fogged up windows when it’s so easy to do something about it. Windows are for looking out of after all!