Do I need new Dble/glazed windows?

no1catman

Two bedrooms, one has large picture window, the other a bay-window with four sections.
The first one - no problems, the second window in the morning covered in condensation, and with the sealant 'gone' afraid it's leaking down into the wall!

The only other difference between the rooms that could effect it - the door is closed with the bay-window one.

Q: Do d/g windows deteriorate over decades? What are the 'signs'?

TheCyclingProgrammer

As far as the condensation goes, the starting point would be establishing the humidity levels in your house and if there's anything you can do to reduce it.

Get a cheap hydrometer - comfortable humidity levels are generally considered to be between 40-60% relative humidity at 20C though you may still see condensation problems at the higher end of this range on very cold surfaces (like older double glazing or single glazing).

If the average humidity levels in your home are at the high end of this range or worse, above 60%, you should look to try and reduce it. Usual advice is keeping doors on kitchens and bathrooms closed when cooking/showering, making sure you have good extraction, keeping the house ventilated when weather permits etc. You can also reduce your humidity further by investing in a dehumidifier.

However it is possible that your windows are old enough that they are getting so cold when the weather is cold outside that even at reasonable humidity levels you find yourself getting some condensation. In this case you need to just decide whether you can live with it (and wipe it off each morning) or invest in modern double glazing units (you don't necessarily need to replace the windows, although the frames do count towards the overall window's energy rating). There could be numerous factors that are resulting in condensation.

To give you an idea - we have a similar problem. The windows in our house were all replaced around 2002-2004 (we have the paperwork from the previous owners) - that is before building regs changed and windows had to meet minimum levels of energy efficiency. They may or may not have been gas filled, they don't have warm edge spacer bars and they probably don't have any special low-e coatings.

We were getting RH values of high 50s in our bedroom (where the problem was worst). Our bedroom window suffered the most as the whole window was covered in condensation in the morning. There might be other contributing factors in our case - when we refurbished the house we insulated the timber framed external wall at the front of our bedroom (its a small overhang over the downstairs bay) and to prevent interstitial condensation we covered the insulation with a vapour barrier. As a result, whilst the front wall is now nicely insulated and stays warm, the window is by far the coldest spot in the room and any vapour in the air has nowhere else to go (it can't penetrate the walls due to the vapour barrier). We also have plantation shutters on the window which probably partially insulates the windows from the heated room (even with the louvres open) making the window even colder and the only ventilation in the room is a small vent on the old chimney breast. Opening the window can sometimes reduce the problem but it also lets heat escape from the house.

We bought a dehumidifier and its proved very useful for drying clothes indoors without using the tumble dryer (we can stick an airer in the conservatory with the dehumidifier on clothes drying mode) and for generally lowering levels in the house. We often leave it on the landing on low mode for a few hours each night and it brings the RH levels in our bedroom to the high 40s. As a result we only tend to get condensation on the windows when its very cold outside (< 5C) and even then it only tends to be an inch or two at the bottom (where the window would be coldest) which is easily wiped off.

Having seen the difference low-e coated modern glazing can make (our front and back composite doors have energy efficient glass, as does the 10 year old conservatory) I have no doubt that modern units would probably eliminate the problem entirely but I'm not sure its worth the expense as the units are otherwise fine. If we ever start getting condensation between the panes then we will replace them, one by one over time.

TheCyclingProgrammer

Forgot to mention your "sealant" problem. What do you mean by this? Could you post a picture? Condensation on glass is not a massive problem in itself (mould won't grow on the glass) but if your walls are getting damp then this could very quickly lead to black mould.

SailorSam

When you ask does DG deteriorate ? It can fog-up if the seal has gone. You don't need to buy a new window, just the panel.

Slinky

Have you tried leaving the door of the bay windowed room open at night and comparing the results with the other room. Are people sleeping in both rooms? We get a lot less condensation on our bedroom windows if we leave the bedroom door open at night. These windows are only about 8 years old, others are over 30 and there's not a lot of difference between the amount of condensation we get if we sleep in a room with the older windows. With us, it's people in the rooms rather than a problem with our windows.

thebaldwindowfitter

Does this bay window have brickwork or tiling below it ?.do you heat the room at all and do you do like most people have your heating on timed instead of a constant temperature because if you lets say have your heating on 6-9 morning then 3-10 evenings this can cause condensation even more so if a gas fire is used

thebaldwindowfitter

thebaldwindowfitter wrote: »

Does this bay window have brickwork or tiling below it ?.do you heat the room at all and do you do like most people have your heating on timed instead of a constant temperature because if you lets say have your heating on 6-9 morning then 3-10 evenings this can cause condensation even more so if a gas fire is used

In order to help can you let us know some more information ??????

ROY47

open the windows a little at night
see if you get same problem

ventilation needed