You may have appreciated the benefits of double glazing and installed such windows on your property. While double glazing is excellent in retaining heat in your house, it will not last forever. So, when is it the right time to replace the double glazing?

What to look out for

The following are indicators that your double glazing is failing;

  • Leaks
  • Draughts
  • Condensed water between the window panes
  • Chips, holes and cracks


The points highlighted above are pretty obvious. You may have encountered them in several buildings. The issue is how to handle them. How are you supposed to determine whether such issues are affecting the performance of the window? There are two options when the double glazing fails, repair or replace.


Condensation is a physical process that involves vapor changing into a liquid. Condensation will occur when the temperature of an object, in this case, the glass or frame, falls below the dew point specific to that surrounding. The water vapor in the surrounding air will change to water droplets which will form on the surface of the object. The rate of condensation is dependent on humidity. Very humid conditions dictate that the condensation will occur at higher temperatures.

Problem 1- condensation on the outside surface of the windows

Remedy- Condensation is an indicator that there is enough heat inside the room. The water droplets will disappear as the temperature outside increases.

Condensation on the outer surface of the panes occurs when the glass surface has a lower temperature than the temperature outside and the dew point of surrounding air is higher than the temperature of the glass.

Condensation on the outer surface is a common phenomenon at night and early in the morning in a cloudless sky and in windless weather. It only occurs on well-insulated windows. This occurrence should be seen as evidence that the window is performing in terms of thermal insulation.

Problem 2- there is condensation between the two glass panes. Such is a big issue since it shows there is a leak between the two panes. The gas-filled cavity between the two panes is not sealed. This phenomenon demands replacement of the whole unit.


Problem 1- a noticeable draught

Remedy- a noticeable draught is an indicator that there is a broken seal in the window. The broken seal could also be around the frame. If the draughts originate from between the window frame and the building bricks or blocks, the sealant is worn out. The remedy to this is to replace the sealant between the sealant frame and the bricks.

Problem 2- draughts between the window frame and glass panes

Remedy- such draughts indicate that the sealant between the frame and window panes is worn out. A temporary solution would be to replace the sealant. Such a repair will not achieve much efficiency. Replacing the windows is the perfect solution.


Problem 1- leaks via the frame

Remedy- such a problem is caused by a failure of the weather seal or failure in the drainage section. If the problem is the weather seal, replacing it will solve the problem. If it is a drainage block, you will only need to clean the window.

Problem 2- leaks between the frame and the walls.

Remedy- the sealant around the frame is failing resulting in gaps that are allowing water in. if the windows are under the warranty period, the manufacturer is supposed to replace the windows at no charge. If the warranty period is over contact a professional for repair. Alternatively, replace the windows. The failure may be as a result of the age of the windows.

Holes, chips, scratches, and cracks

Problem 1- the glass of our window has cracks, scratches or holes

Remedy- a scratch may not mean big problems. But any other of the above anomalies will dictate that the glass is replaced as quick as possible. If not replaced there will be condensation and total failure of the whole system.

Problem 2- the frame has chips, cracks, and holes

Remedy- such problems turn into big issues if they run deep into the frame. Deep cracks, chips, and holes will allow draughts into the building. A total replacement of the window may be required if the damage is deep. In some cases, a simple repair may solve the problem.