Double glazing is one of the best investments you can make in your home. It helps retain heat, reduces outside noise, and cuts down on energy bills. However, even the best double-glazed units can develop problems over time. One of the most common issues is a blown or foggy (misted) double-glazed unit, where condensation becomes trapped between the panes of glass. This not only spoils the look of your windows but also reduces their insulating ability, making your home less energy efficient.
If you’ve noticed your once-clear windows becoming cloudy or misted, you’re probably wondering how long it will take to get them fixed. At RPS Double Glazing Repairs, we specialise in quick, affordable, and reliable double glazing solutions for homeowners in Bournemouth, Poole, Ferndown, and surrounding areas. In this article, we’ll take a closer look at what causes blown units, the typical timescales for repair and replacement, and what you can expect when you book a service with us.
A “blown” or “foggy” unit occurs when the airtight seal that holds the two panes of glass together fails. Once the seal is damaged, moisture from the air seeps into the space between the panes, creating that misty or cloudy appearance that many homeowners dread. Unlike surface condensation, which can be wiped away, the fogging inside the unit cannot be cleaned off because it is trapped between the glass.
Signs of a blown unit include persistent misting, visible water droplets inside the glass, and draughts around the window edges. Over time, the insulating gas (such as argon) between the panes escapes, and the window’s thermal efficiency drops significantly. This can lead to cold spots in your home, rising heating bills, and in some cases even mould growth due to excess condensation. The most common culprit behind a failed unit is a deteriorating seal or a worn-out swiggle strip, which is the spacer bar that keeps the panes apart. Once this component fails, replacement is usually the only long-term solution.
When you first contact a glazier, they will usually carry out an inspection to confirm whether the unit has failed and assess the condition of the frame. This typically takes no longer than an hour and can often be arranged quickly, especially with a local company like RPS. During this time, the glazier will measure the unit, check for frame damage, and advise whether a simple repair or a full replacement is necessary.
If the seal is damaged beyond repair, a new sealed unit will need to be manufactured to fit your existing frame. Because each unit is custom-made to size, the ordering process usually takes between 5 and 10 working days. For unusual window shapes or larger panes, this might take slightly longer, but most standard sizes are available within a week.
Once the replacement unit arrives, installation is usually straightforward. A small standard window can often be completed in half an hour, while larger windows, patio doors, or bay windows may take closer to 90 minutes. If several windows need attention, the work can be completed in a single day depending on how many units require replacement.
In most cases, from the initial inspection to installation, the entire process takes around one to two weeks. This makes it a relatively quick and simple home improvement compared to other types of building work.
Although the process is usually quick, several factors can influence how long it takes to repair or replace a blown unit.
Window Size and Type: Larger panes of glass, shaped units, or specialist glazing can take longer to manufacture and install.
Number of Windows: A single window is quick to replace, but if several units across the property are affected, this will add to the total time.
Frame Condition: If the existing uPVC or timber frame is damaged, extra work may be required to restore it before the new glass can be fitted.
Glazier Availability: The schedule of the repair company can also play a role, though local specialists like RPS often offer flexible appointments to fit around your needs.
Understanding these factors can help you set realistic expectations for your repair and plan accordingly.
When dealing with misted double glazing, homeowners often wonder whether it is possible to repair the existing unit or if replacement is the only option.
Repair (short-term fix): Some companies offer treatments such as resealing or fitting vents to draw out the moisture. While this may improve the appearance in the short term, it rarely lasts. Because the insulating gas has already escaped, the window’s efficiency will remain compromised.
Replacement (long-term fix): Replacing the entire sealed glass unit is the more reliable option. This restores the full insulating properties of the window, ensures clarity, and often comes with a guarantee. Importantly, the replacement unit can be fitted into the existing frame, saving you the cost of a brand-new window.
At RPS, we generally recommend replacement double glazed units as they provide a longer-lasting and more cost-effective solution.
If you have misted or foggy windows, don’t delay in getting them looked at. The problem will not resolve itself, and over time your home will become less comfortable and less energy efficient. At RPS Double Glazing Repairs, we provide fast, affordable, and professional repairs across Bournemouth, Poole, Ferndown, and surrounding areas.
Contact us today to arrange a free quote and find out just how quickly we can restore your windows to their best.