Glazing Leaks - Why Your Windows “Weep,” And What You Can Do About It

Glazing Leaks – Why Your Windows “Weep,” And What You Can Do About It

Let’s face it – leaks are never a good thing. From tents to roofs, bicycle tyres to windows, and everything in between; if it’s leaking, it’s a problem. Glazing leaks are particularly annoying because let’s be honest, most houses have a lot of windows! So the potential for leaks is high.

But the news is not always bad. Some leaking windows have simple, easy-to-remedy causes that require nothing more than a little silicone sealant to rectify. Of course, some problems are more serious, so let’s take a look at some of the reasons why your windows are leaking, and what you can do about it.

Common Reasons For Glazing Leaks


Just like people, windows become less air- and water-tight as they age! Years of exposure to rain, wind, sun and temperature fluctuations can warp window frames, seize putty and damage glazing seals. When one or more of these things happen, windows can shift out of their original position, allowing water to enter.

Poor House Design

When a house isn’t designed properly, glazing leaks can be experienced. This is not so much due to improper installation, but more because the design of the house is such that it doesn’t adequately protect the windows from the elements. For example, if the fascia boards are angled inwards, towards the house, instead of outwards, away from it, water will channel down directly onto the windows. In addition, if there aren’t enough roof overhangs to prevent rainwater from being driven onto the windows by the wind, this puts pressure on the integrity of the window seals.

Incorrect Installation

If builders don’t use the correct window flashing, water can easily seep behind the inferior substitute material and settle in the spaces around the windows. Over time, this water builds up, eventually finding its way around the frame and through into the house.

Lack Of Maintenance

If glazing putty isn’t checked regularly, and cracked, missing or perished putty replaced, the integrity of the glass seal will be broken. This allows condensation and moisture to seep in around the edges of the glass.

Unlevel windows

Windows that aren’t level are the most common cause of glazing leaks. A skew window lets water build up between itself and the wall (which is – hopefully – straight!) This water eventually accumulates to such a degree that leaking is inevitable.

Leaking Roof

Yes, sometimes your leaking window is actually caused by your leaking roof! If water comes in through the roof or chimney, it is not unheard of for it to follow a path along wall studs or ceiling joists until it gets to a nice, absorbent wooden window frame! The water then drips inside and pools to the point where it seeps out onto the inside of the window.

Fixing Glazing Leaks

The bad news is, the above are just some of the many, many reasons why your windows are leaking. The good news, however, is that you can fix a lot of leaking windows by yourself! As long as you have the right products and a little bit of DIY know-how, you’ll be able to repair the leak without professional help.

Occasionally, however, if your window is leaking beyond the window itself, or if the leak has weakened the integrity of the structures holding the window in place, the only thing to do is to call in an experienced professional for a proper assessment of the situation. Sometimes, depending on the nature and severity of the leak, an entire window replacement may be necessary.

This is, of course, the worst-case scenario, but if you have any doubts about why your window is leaking, and what you can do about it, chat to the professionals at GHI. We stock a variety of silicone sealants and accessories ideal for fixing glazing leaks. We supply a wide range of aluminium window hardware if you feel the time has come to replace your weeping wooden window with a hard-wearing, low maintenance aluminium windows.

Remember that a leaking window isn’t just a threat to your window frames and carpets, it could also pose a threat to your health. Mould thrives in damp and humid environments, and you may already have noticed the tell-tale dark and unsightly marks at the bottom of your window frames. Mould exposure is characterised by symptoms, not unlike colds and flu. More serious complications can occur if the mould is left untreated.

Stop mould and glazing leaks – contact GHI today.

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