Double Glazing Problems

window energy efficiency

In general, UPVC double glazed windows are long-lasting, secure and hard wearing, however problems do sometimes occur. The most common issues with double glazing tend to be related to sealed units. Read on to learn about common double glazing problems, and how to handle them.


Condensation occurs when water vapour hits a cold surface. Steam, or general moisture in the air, condenses back into water droplets. Usually, having double glazing reduces the amount of condensation that occurs in your home. However, if your home is insulated, draft proofed, and has double glazing then it could become a moisture trap. To determine whether the double glazing condensation problems you have are indicative of a something serious, look at where the water is gathering.

  • On the inside pane: Condensation on the inside of the inner glass is an indication that the temperature of the glass is too low for the atmosphere and water vapour content of the room. Check out this handy guide to find out ways to reduce the amount of condensation in this situation.
  • In the cavity: Condensation inside the cavity of your window is sign that there is a problem with the seal of your unit. There should never be condensation in between the two panes of a hermetically sealed unit. If you see condensation there, it is usually a sign of either leakage of moist air from the room into the window cavity, or that something inside the air space itself contains moisture. You should have an expert examine your windows to determine how to fix this issue.

Other Common Double Glazing Problems

Double glazing is designed to provide insulation, reduce noise pollution, and stop drafts. However, as your installation ages, it is common for the sash to drop, and the hinges to become worn. This leads to several problems:


If you notice draughts coming from your double glazed windows, this is usually a sign that the windows are not closing properly. This is usually caused by one of the two wear-and-tear related issues mentioned above.
To diagnose the problem, close the window and check the side with the hinges. If there is a gap between the sash and the frame, then this means your hinges are damaged. If the hinges look OK, check the lock by sliding a credit card between the sash and the frame. If the card moves freely, then you need to tighten the lock. If the gap is tight, then you have nothing to worry about.
The final likely cause of draughts is a dropped sash. This usually occurs in windows that have side openings. Close the window, and look at the top corner above the handle. If you can see daylight where the sash is supposed to meet the frame, then your sash has dropped, and will need adjusted.

Broken handles and hinges

Broken handles, hinges and locks should not be ignored. As mentioned earlier, damaged hinges that prevent the window from closing correctly lead to draughts, and this essentially eliminates some of the main reasons for having double glazing.

In addition, broken window locks are a serious security issue. Your home insurance may be invalidated if your windows are not correctly locked. For this reason, and your family’s safety, it is important that you fix the problem immediately.


Is it Time to Upgrade Your Windows?

If you live in an older property that has one of the first generation sealed double glazing panes or even a property with UPVC windows and single glazing, then you may find that updating your windows will save you money. Some common problems with older UPVC installations include:

  • Discoloured UPVC frames: While UPVC is quite hardwearing and easy to clean, it will eventually become discoloured. If cleaning the plastic with a specialist UPVC cleaning product does not remove the discolouration, then it may be time to replace the frames.
  • Improving your glazing: If you currently have only single glazing, then you should definitely consider investing in double glazing. Double glazed windows reduce noise pollution, stop draughts, and help to regulate the temperature of your home. If you already have double glazing, but you live in an area which gets a lot of wind, bad weather, or noise pollution, you may want to update to coated, low emission glazing solutions.
  • Updating less energy efficient windows: Double glazing comes in many different flavours. Early double glazing was certainly better than single pane glazing, but there have been many advances in glazing over the last few years. Modern “Low-E” windows are filled with a special low emissivity gas to ensure that short wavelength heat from the winter sun is allowed into your home, but that the heat inside your home does not leak out. This saves you a lot of money on your heating bills, and keeps the temperature of your home comfortable all-year round. Check out this document to learn more about how low-e windows work.
  • Poor security: Many older windows feature simple locks (or worse, no locks at all). Not only is this dangerous from a security point of view, it could be costing you a lot of money. Improving the security of your windows may result in lower insurance premiums.


Repair or replace?

Damaged hinges and dropped sashes can be repaired for you by a specialist.

Issues with seals, however, are more difficult to repair (but not impossible). If you are unsure whether you should repair or replace your double glazing, consult a company such as Window Doctor, who can examine your windows and offer advice, as well as a free quotation.

Replacing your windows will require a substantial up-front investment, but over time that investment will pay for itself. If you do not have double glazing at the moment, speak to your local authority to see if they offer any financial aid for people looking to make their homes more environmentally friendly.

48 Responses to “Double Glazing Problems”

  1. Mr Cousins says:

    i have this orange goo between my double glazing window plane can you tell me what it is.

    • stormclad says:

      Hello Mr Cousins,

      Thank you for your comment. I’m afraid it’s impossible to tell what it may be without actually seeing the problem. If you would like we can arrange for a member of our team to come out and diagnose the problem for you and provide a free quotation for putting the problem right.

      If you call 01159 708077 we would be more than happy to arrange this for you.

  2. Emma says:

    Hi i was hoping you may be able to explain my strange happenings , as i came to go to bed tonight i walked past my frint door and heard a crackling noise so i turned the light on, and couldnt believe what i seen, my door window on the inside was shattered ?????? Nothing at all outside and i just cant understand why or how this has happened. I was only at the door an hour earlier putting rubbish out and i dont slam the door as i have a baby in bed, nothing hard has come in contact with the window??? Could you give any explanations??

    • stormclad says:

      Hi Emma,

      This is uncommon but does happen on rare occasions. It is likely to be a stress fracture of the glass. This is usually caused by a change in temperature, which can put too much pressure on microscopic weak points/flaws in the glass, which can eventually lead to the piece of glass cracking.

      I hope that helps you to explain the strange occurrence!

      If we can be of any more help, please give us a call on 01159 708077.

  3. Kalab says:


    Looking for some advice if possible please.

    We had new double glazing installed 18 months ago and have had the company out 3 times to check over them.
    Particularly to look over the bay window area in our living room.
    There is a clear and distinct draught from around the windows. Also I can hear cars diving past esp when there is water on the road. This is also prevalent in 2 bedrooms. The co (based in East Kilbride) have come out and made adjustments on the windows that seem to limit the noise. Not sure exactly what but it seems to work for a while. The draught issue does not improve and through the summer months this does not bother us. In the winter time the cold air goes all the way through the living room.

    I now believe that the draught is coming not from the window but from around the windows due to gaps between the windows and the surrounding house? Do you think this could be due to poor installation? and if so what the potential remedy may be?. Where I probably lose understanding of this is- what, if anything, is packed into the side of the frames to stop draughts etc? Thank you for any help.


    • stormclad says:

      Hi Kalab

      Usually there is a compression seal on the edge of the openers that will eliminate most draughts and some noise. For noise reduction A rated units filled with argon gas and using warm edge technology will eliminate noise. Without seeing the installation it is impossible to pass comment professionally. Some window systems are better than others for both of these factors.

      I would suggest you contact the original installers again to see if you can finally get a conclusion to this.


  4. John Peters says:

    My home was built in late 1970’s and I believe were originally fitted wiith double glazed uvpvc windows in white with Georgian Bar.

    In 2012 two sealed window units inner panes (both upstairs front bedrooms) suddenly broke. One in the early hours when I was in bed and it imploded slowly cracking from top to bottom but fractured across the whole ppane. This recurred last week but a seperate unit in the same frame and one downstairs in an extension to the original house.

    Any idea what is the causal factors?

    • stormclad says:

      Hi John,

      The only thing I can suggest is the information on the previous post below. The only other thing that might cause this is obviously movement in the house itself (hopefully not the case, but worth keeping an eye on).

      This is uncommon but does happen on rare occasions. It is likely to be a stress fracture of the glass. This is usually caused by a change in temperature, which can put too much pressure on microscopic weak points/flaws in the glass, which can eventually lead to the piece of glass cracking.

      I hope that helps you to explain the strange occurrence!

      If we can be of any more help, please give us a call on 01159 708077.

  5. Ian says:

    My windows were fitted a couple of years ago. Now whenever its windy the windows make a howeling noise which is enough to stop you sleeping.
    is this easy to solve if so how

    • stormclad says:

      Hi Ian,

      The whistling sound that you speak of can potentially be caused by a couple of factors:

      Firstly, if it is the actual sash that the wind is coming in through, the compression caused when closing the sash is not high enough. This can allow small amounts of air to rush through in high winds which can cause the whistling sound that you speak of. To remedy this, the window would have to be adjusted to ensure that the window fully closes. However, there are rare conditions where the wind is hitting the window at a particular angle causing it to be practically impossible to stop the noise, as it vibrates the gasket that seals the window shut.

      Failing this it is likely that faults on the sealant used around the window frames are allowing air to rush in and cause the sound. Basically, when there are small flaws or cracks in the sealant, air can rush through and create a whistling noise. Unfortunately, it can be difficult to locate exactly where the air is rushing in, but the issue can be remedied through resealing the window if this is the issue.

      If there is any way that we can help further then please give us a call on 0115 9708077.

  6. deb says:

    We had a bow window fitted a couple of days ago and both the top opening windows have a piece of rubber seal missing, it’s around 3cm long on each of the windows and the rubber that’s missing should come into contact with the main window frame when the window is closed. I’ve been told by the company that it’s nothing to worry about but I’m not convinced . Do you think this is a manufacturing fault?

    • stormclad says:

      Hi Deb,

      Without seeing the actual window it is very to difficult to comment on whether all the seal/gasket that is supposed to be present is in fact there. However, if it does seem as though the window is letting in cold air when closed and not fully sealing it would suggest that there may be a fault, but again it is very difficult to say without having had a look. If you are from the Midlands area and would like to speak to one of our advisors with the view of someone coming out and having a look for you then please do not hesitate to give us a call on 01159 708077.


  7. Elaine says:

    We had double glazing put in just over 3 years ago and the sealant is coming away. How long should your sealant last? Thanks

    • stormclad says:

      Hello Elaine,

      The length of time that a sealant should last for is dependant on a number of factors. For example; whether it is an internal or external seal, the amount of exposure to direct sunlight etc. The sealant on all of our double glazing is guaranteed for ten years as this is how long we guarantee our windows for, therefore we will go back to a job and replace the sealant for a period of ten years after the window is fitted free of charge. Whether you are able to call upon the company that fitted your windows to come back and repair the sealant will depend on the length and details of your guarantee.

      I hope this information helps, if you have any more questions or anything that we may be able to help you with, feel free to call us on 0115 9708077 and we will be more than happy to help,



  8. Ms Anderson says:

    I have just had new plastic framed doubled glazing installed. I have noticed that dirt and grime has accumulated below the top of the seals on the outside of the glass. The build up is approx 2 to 3mm in depth and it already looks horrible and I’m sure within a couple of months it will turn that nasty green colour. I have contacted the installer and they say it is normal to have a gap to allow water to run down.

    • stormclad says:

      Hi Ms Anderson,

      Thanks for your comment. Only having read your comment rather than seeing the actual window it is difficult to answer your question 100% accurately. However, I can confirm that our windows have in-built drainage system, comprising slots within the thresholds that allow any water ingress to flow to the outside. To ensure an efficient system these slots must remain unblocked. Therefore, the first thing that we would check is that these drainage holes have been drilled and they are unblocked. I hope this information helps, if you would like to discuss this matter further or have any other queries then please give us a call on 01159 708077 and we will gladly help.



  9. lisa says:

    We had new double glazing installed 2 years ago and every time it rains the water seems to be getting in where the three points (wall, seal board and window) meet in the bottom corners (but only one end) its gradually happening to all of the windows n ruining my seal boards n decoration Help! Thanks Lisa saffron walden

    • stormclad says:

      Hi Lisa,

      Without seeing the issue it is difficult to comment what it may in fact be. Our windows are designed with an in-built drainage system, comprising slots within the thresholds that allow any water ingress to flow to the outside. To ensure an efficient system these slots must remain unblocked.It may be worth having a good luck for these drainage holes and ensuring that they are unblocked, again without seeing the windows first hand it is difficult to comment on what the issue may be. If you would like any further advice or to potentially arrange an appointment for us to come and assess the windows, please give us a call on 01159 708077.



  10. Lexus says:

    Thank you for this post. It is very informative. I wish I had read it before when I had a problem with condensation! Thanks again.

  11. Peter says:

    I have a problem with one window which, both casements will not open.
    Both of the casements have the same problem, when operating the handle to open the windows only the top shoot bolt releases the casement and it is obvious that the bottom bolt on both is not releasing. I have never had this problem before and, as there is no external access without errecting a scaffold I would appreciate any suggestions as to how I could possibly resolve the problem. By the way, The window has external beeding.



    • stormclad says:

      Hi Peter,

      The information you have provided would suggest that the mechanisms within the windows are both damaged in some way. Depending on how old the windows are and whether parts are still available, you may be able to source replacement parts. However, if not it is likely that you will have to have the window replaced if you do in fact want the sashes to open. This is somewhat guesswork as without seeing the window it is impossible to give a correct diagnosis, and also difficult to advise on access options, depending on the severity of the problem it may be fixable internally. If you would like to discuss the matter further, or potentially arrange for one of our teams to visit the property (depending on your location), please give us a call on 01159 708077.



  12. Mr p smith says:

    I have a issue with my window fitted 9 month ago.the Windows in question after 3 month would no close, they are bottom opening window.the company have called twice claiming they fixed them only for the same problem to happen again, this time they have used silicon to stick the glass to the frame, wedged the bottom of the window up with spacers and told us not to open the Windows for two day to allow the silicon to set, is this normal practice

    • stormclad says:

      Hi Mr Smith,

      Without seeing the issue first hand it is difficult to comment as we don’t have much idea what the actual issue is, however this does not sound as though it is a “normal practice” remedial method that we would usually carry out. However, as already stated it may not be a normal issue and therefore the company may have had to do something unusual to try to remedy the problem. If you would like yo discuss this matter further, or potentially arrange for us to visit your property (depending on where you are) please give us a call on 01159 708077.



  13. Tina says:

    I ave a new build flat and the windows have condensation on the inside on every window and this then leaves water on the inside window seal – wot could the problem be I have pictures if needed

    • stormclad says:

      Hi Tina,

      It sounds as though you could well be an issue with ventilation of your property. We have an online document that explains the causes of condensation and the best ways that you are able to prevent it. This document is situated here:

      Please take a read, this should help you eliminate your problems.

      Kind regards,


  14. mandy says:

    hi my windows are really wet all over the glass and some are wet between the panes they also seem to be quite cold when hand is put around the seals does it sound like they need replacing i live in private rented property and im unsure where i would stand if they have blown our house has just had the loft insulated and the cavity insulation on the walls but unless the heating is on 24/7 the house is freezing

    • stormclad says:

      Hi Mandy,

      Without seeing the actual windows it would be difficult to say that they definitely need replacing, however it does definitely sound as though the windows have seen better days. Moisture between the two panes of glass would definitely suggest that the sealed units have deteriorated to a point where they are no longer sealed from moisture ingress. I hope this helps, if you would like to enquire further into the possibility of us visiting the property to provide you with further advice, please give us a call on 01159 708077 and we would be happy to arrange this.



  15. Mr c newell says:

    Good Afternoon.
    We just had double glazing on our bungalow replaced as the old was letting in cold air and was always wet.
    All our new windows on the inside puddle water ie condensation on the in side , so much that the seal on the in side of the windows now get’s sticky to touch even after 14 days, the locks on the doors are always dripping water in the mornings as do the windows every morning, when its cold out side, we thought this would stop with new glazing , what do you think could be the problem, we only leave our bed room window open of a night time.

  16. Colin says:


    I recently had 4 new windows and a door installed to the front of my house. The house is a 1966-68 build. It originally had steel window frames which were replaced with aluminium double glazing in the mid 80’s. The new windows are uPVC double glazed A rated windows. I live on a busy road and can always hear the traffic. The new windows haven’t really improved the noise level from the traffic, however this doesn’t really concern me too much as I am well used to the traffic. The problem I have since the installation is a new noise that wasn’t there before. It can be heard in all 4 rooms from the the new windows and even in the landing upstairs. It is definitely coming from the traffic as I can hear it as vehicles approach from quite a distance, as they pass by and then it dissipates as they go off in the distance. It is constantly there if traffic is constantly passing and seems to be louder when vehicles are travelling faster. It’s sounds like road works in the distance, like someone using a pneumatic compactor about 300 metres away. The best description I can give you is that; it sounds like the dull hissing sound of water passing through the central heating when it is on.

    • stormclad says:

      Hello CJ,

      Unfortunately without being able to see the installation and complete a detailed inspection it is difficult to say what the issue is, however it does sound as though it could be a problem with the sealing of the windows. However, as stated it is very difficult to make an accurate diagnosis without inspecting the windows. The best course of action would be to contact the company who installed the windows, who should send a specialist back to remedy the problem for you. If you would like to discuss the problem any further with us, please give us a call on 01159 708077 and we will be happy to help where we can.



  17. david says:

    I have a draught problem with my double glazed front door how can I adjust them.

    • stormclad says:

      Hi David,

      The process of adjusting double glazed doors can vary significantly from manufacturer to manufacturer and with the age of the door. We would be in a position to advise if it is indeed a Stormclad door that has been installed, however it would be extremely difficult for us to advise remotely on a door that is not one that we are familiar with. If you would like to enquire about further information please give us a call on 01159 708077 and we will be glad to help where we can, whether this would mean arranging a visit to your property or pointing you in the direction of the correct information.



  18. MRS B says:

    I am unsure and just require advise please…not sure how many years ago the upvc windows were installed in property i live in..but feel draughts from them and very noisy..put room thermostat on windowsill y/day and within 20 mins temp dropped by 3 that relatively acceptable/normal, or do you think that frames and glass require replacing??..thanks for looking

    • stormclad says:

      Hello Mrs B,

      Unfortunately, without more details and the opportunity to inspect the windows it is very difficult to diagnose what an issue may be and offer a solution to help you remedy the problem. It does sound as though the windows that you are describing may be past their best if they are allowing significant draughts and noise to enter the property, but again, without seeing them it is almost impossible to tell. If you would like us to further investigate for you, please give us a call on 0115 9708077 and we will gladly arrange for a representative to visit your property and advise.



  19. mrs k elliott says:

    hi, would like some advice please if possible,we had our windows and doors in may last year, they have been drafty, the door had dropped so they came and done it, then the side panels on the side of the door, where drafty, so they came back because the man told us the clips hadn’t been put in properly,so that was done he put in some extra clips to stop the draft, but now there not sitting flush and are still drafty, also l can feel a draft in the front windows, my son was talking to mr the other day, and facing the window, iy was dark outside and very windy, and all of a sudden he said he could see the glass move with the windy, l didn’t think this could be right so l got up and had a look myself, and yes when the wind blows the glass actually bows in, is this right for them to do this, they are very big windows nearly three metres wide they have side openings, is this normal for windows to do this in windy conditions, l don’t want them to think im mad if l tell them the glass actually bow in when windy, thank you.


  20. pat says:

    we screwed in small curtain hooks into the frame right on the corner, the owners are now worried this will cause condensation they are not anywhere near the glass please advise

    • stormclad says:

      Hello Pat,

      Thanks for your comment and apologies for the delayed response

      So long as the screws do not penetrate the outer/external face of the window his should not cause a problem, as you have also pointed out you do need to ensure the screws do not come into contact with the glass as they could cause it to shatter.

      You can find more information in relation to condensation at

      I hope this is helpful,

      Regards Stormclad

  21. Gail says:

    I had double glazing fitted 10 years ago. When I close window with handle at bottom of window there is a gap at top left of window although when I go outside I can push closed. Any suggestions?

    • stormclad says:

      Hi Gail,

      Many thanks for your comment. Without seeing the window it is difficult to advise, however it does sounds as though there is a problem with the locking mechanism. If you would like to discuss this further, please give us a call on 0115 970 8077.



  22. Terry says:

    We have recently purchased a bungalow and have been render acting it, it has been replays termed throughout but the front 2 rooms have what appears to be a orange tint on the inside of the double glazed units. These rooms are at the front of the bungalow and we did have window lene smeared over them for a day to stop anyone looking in, but we removed the window lene and replaced it with newspaper. Do you think either of hue above has caused this problem and if so how can I get rid of this orange tint and I have tried various glass cleaning product without ant success.

    • stormclad says:

      Hello Terry,

      Thank you for your question,

      Some of the coatings used on glass can be seen in certain circumstances, in particular ‘K’ Glass does have a tendency to have a strange hue under some light conditions. It is difficult to say for sure but if you would like us to arrange a visit to inspect the problem please do give s a call on 0115 970 8077.

      I hope this helps,

      Regards Stormclad

  23. Linda says:

    I had a new upvc bow window fitted last year and I am unhappy about rain noise on the roof of it. We had no noise from our previous bow window. Should I expect this or could there be a problem.

    • stormclad says:

      Hi Linda,

      Thank you for your comment,

      It is difficult to say for sure without having done a site inspection but it does sound like the problem may be caused by a lack of insulation in the new bay roof. Insulation does reduce heat loss but it also acts as a sound insulator. It may be worth asking your installer to confirm that they have installed insulation into the new bay roof, for acoustic and thermal reasons this s a worthwhile consideration.

      I hope this is helpful,

      Regards Stormclad

  24. Stephen Johnson says:

    Two years ago we had new doors and windows fitted (2-uo 2-down terrace house with cellar at the front. Since then there has always been draughts, particularly at the front of the house where the cellar is. We get draughts in the front bedroom from above where the front door is. Other draughts seem to come from around the windows, rather than through them The installer has been back to check the exterior seals, which he says are OK, and has re-sealed the interior seals with a thicker seal (which has had no effect). Is it possible that some damage was caused to the cavity during installation, and that we are getting draughts up through the cavity from the cellar to the rest of the house? He has offered to re-install one window, so I suspect that he realises that there is something wrong. He is backed by an Ombudsman scheme – should we raise the matter with them?

    • stormclad says:

      Hi Stephen,

      Thanks for your comment, although it is difficult to say for sure without having seen the installation it does sound like the problem is due to poor sealing around the frames. Whilst silicone will help to seal the frames to the brickwork and prevent water ingress is does not always cure drafts effectively. It is good practice to use expanding foam to fill larger gaps between window frames and the surrounding brickwork before sealing with silicone. It would certainly be worth checking to ensure this has been done, if you cannot resolve the issue with your supplier please to call us on 0115 9708077 and we will do what we can to help.

      I hope this is helpful,

      Regards, Stormclad

  25. george humpage says:

    I am considering having double glazing in cream coloured units, but all the samples have a undercut at the weld or a lip at the mitres. Is this common practice with all double glazed PVC units? Thank you.

    • stormclad says:

      Hello George,

      Thank you for your question.

      It is common for white UPVC windows to have a groove where they are mitred but this does not usually apply to coloured or foiled products. We have just recently replaced the windows in our head office building at Basford, Nottingham with cream frames and I have to say they do look stunning.

      Please feel free to call us on 0115 9708077 if you would like to arrange a visit or if you would like us to demonstrate how our windows are constructed.

      Kind regards, Stormclad

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