Fogged Sealed Windows

[John]

Any thoughts on this process?

[dennis]

The seal has gone. They are faulty and need repairing/replacement.

I have one which I must get done at some point. Its toughened glass so I may just find somewhere that will reassemble the unit with new spacers and silica gel if I strip the old seal.

[The Natural Philosopher]

replace windows.

[Harry Bloomfield]

If you fancy repairing yourself....

Get hold of one fish tank air pump with both air input and output port, a few yards of suitable flexible tube, a large tin biscuit box and enough silica gel to fill it.

Drill two holes in the windows seal, in opposite corners suitable size to be able to push the tube in. Do the same in the tin box, fill with dry silica gell and seal the lid on with tape.

Now fit the tube sealing it into the box, the window and the pump. It should form a complete circle, recycling the same air - window, pump, dry the air as it passes through the box, then finally the dried air returns back to the window. Warm weather will help make the process quicker, but run it for a day or two.

Finally and once dry - remove the pipes from the window and seal the holes with some sealant. Remove the pipe pumping air into the window first and seal it, allowing the pump to create a slight vacuum between the panes, then quickly remove and seal the last hole.

Obviously there will still be your original leak(s) to fix. Perhaps others might be able to suggest something suitable to act as a sealant around the outer edge?

Now move on to the next window - remove the silica gel from the box, dry it out in a warm oven and start again.

[John]

Replacement seems very wasteful (green issue). There should be something better.

[Harry Bloomfield]

A green solution to the problem :-)

[The Natural Philosopher]

'Should' and 'is' have never been the same word in the English language.

[MM]

One of my French windows (i.e. doors) onto the lawn has this problem. But what does it matter? I can't see that it makes any difference. Say the room loses a little bit more heat, well, in summer the doors are open most days anyway, and in winter the room is barely heated. I'll get it fixed before the NHBC runs out or if I decide to sell.

Why don't we have the German-style metal or plastic roll-up shutters on the outside of our windows? You never see them in the UK.

MM

[Mike Barnes]

Start to answer your own question: why don't *you* have them?

I do.

[Andrew Gabriel]

I doubt this is worth the effort. The dessicant in the sealing strip is still all spent. You've probably now got an even bigger leak in it too. I suspect it will fog up again very quickly. Also, the condensation eventually leaves a deposit on the glass which needs cleaning off.

BTW, there's no vacuum or reduced pressure between the panes. Any attempt to create one would just suck in moist air.

Take it apart, clean it, and take it to a glazier to be remade into a new sealed unit, unless it's Pilkington K or similar in which case ask the glazier to take it apart and clean it. (Actually, I don't know if the K layer is cleanable at all - it is easily wrecked.)

Whilst it's out, check the area of the frame the sealed unit rests in. Clean it out and make sure the drainage holes work such that water in the channel drains away. The glass unit should be fitted on spacers to keep it above the water channel. One of the main reasons for seal failure is the edge of the unit sitting in a puddle of water which didn't drain away, and which might even be going thought freeze/thaw cycles in cold weather.

[Tanner-'op]

John,

There is! Simply look in yellow pages for "glaziers" local to your area and get them to assemble and fit a new double glazed unit (not a complete 'window') for (at a ball park guess and depends on firm an area) around £20 or so a square metre.

Or if you know the firm that supplied the windows - get them to do it.

This by the way is a common problem - and it's no different to replacing a cracked piece of single glazing.

Tanner-'op

[John Weston]

That's what I was told when I had a blown pane replaced a few years ago

- get a new one made by a factory to modern standards. Also it's much cheaper than replacing the whole window, since you avoid the DG firm "profits" :-)

I agree. I though it would be better to have a positive pressure, if anything.

Would a "normal" glazier be able to remake a new sealed unit? I thought this would require some form of machinery to reconstruct the sealing complete with fresh sticky-stuff and dessicator. Wouldn't this be a more expensive process than simply ordering a new pane? The glass would be the cheapest part of the assembly. OK, recycle the old glass but that seems not worth it - we can't yet put window glass in our glass recycling bin.

A much better isea - you can make excellent cold-frames or greenhouses from old double-glazing panels...

[Andy Hall]

Because, rather stupidly, windows here generally open outwards.

[Rod]

But inward opening windows can be problematic for curtains. E.g. if you wish to leave bedroom window open at night but close the curtains.

[MM]

They are rare in GB. I have yet to see any house with them.

Where? Postcode?

MM

[MM]

You can roll the shutters up during the day.

MM

[MM]

My German relatives have the windows that can be tipped at the top or, with the handle twisted, opened from the side. Tipping the window at night doesn't disturb the curtains unduly.

MM

[Andrew Gabriel]

Problem is that K glass is different colours from different batches. If you have a new one made, it probably won't match your existing windows. If your windows predate April 2002, then they probably aren't K glass (and replacement glass doesn't need to be either) - if you put a piece of K glass in, it will look noticably darker than other panes with plain glass.

I think it will depend on the glazier.

[Rod]

Indeed - I have seen such things in Germany. But I did post "can" - because it is sometimes awkward to have a) inward opening windows; b) external plastic or metal shutters; c) properly hung curtains - all together. I do believe that shutters are often used instead of curtains (or maybe with a light net or voile) - which would be a way round the problems.

[Rod]

Actually, if they are your shutters, you can roll them up at any time. But the point is that shutters can provide protection against intense sun - in which case many people want the shutters closed (maybe with the air gaps between slats) and the iwndows open at the same time.

On a cold winter night with closed windows and closed shutters (and closed curtains :-) ) - no problem.