Do these things exist? I'm thinking of replacing our existing rattly old sash windows with double glazed units, if they are avalable at a reasonable price...
There are (as usual!) complications: Notably, it's a Grade 2 listed building, in a conservation area and inside the boundaries of Dartmoor National Park... (So I'm already facing complications!)
Any recomendations on a Devon supplier who might know about these things?
Cheers,
Gordon
In article , Gordon Henderson writes
They certainly do, I have a large bay windowed area with five in. They have good quality seals all round which I'm pretty sure would pass Ted Moult's feather test (for older readers). They old ones were too far gone to save and the arrangement makes DG worthwhile.
The listing may cause you a bit of difficulty as DG will always look slightly different but my supplier has a lot of experience with listed installations. Things are a lot easier if you don't have individual lights in each sash as putting in astragals (glazing bars) and individual DG panes gets expensive. I went for a halfway route and got large DG panes then faked the astragals on top later with mouldings (v time consuming) but that may not satisfy the listing authority. I've seen better fakes in an old mill (likely listed) where the DG unit had fake astragals inside the DG units then mouldings were added inside & out to improve the fake but then it would prob cost as much as sep panes. Mine were cheap but I did a lot of finishing myself, if I was doing it again I would have had them do the astragals & apply a factory finish paint job, they'd have been twice the price but the time saved would have been worth it.
Sorry no, and I think you are right to look for a local supplier as these things were made to different styles all over the country so local knowledge would be useful, you'd also have easier comeback in case anything goes wrong. If it helps, by supplier was Blair Joinery of Greenock:
There is at least one poster here who makes these styles of windows for a living but I don't know if he's a fan of DG, I'll leave him to offer comment himself.
Also, have you looked at the refurbishment and draught proofing options? There are a few outfits that will take the lot apart & refurb with new beads and draught proof seals, have a google for the names. For small windows, the difference between SG & DG is not as big as some people think and most of the heat is lost through draughts.
HTH
You can get double glazed units fitted into existing windows, but it's a bit of a butchers job, and the results (apart from preventing condensation) are not worth it, IMO.
You're much more likely to have success with secondary glazing, which is available for listed buildings. Have a Google for "secondary sash listed building" or similar. Quick examples:
Bung some extra bits into Google, or e-mail/phone.
Sorry, I forgot to add, if you just want to stop them rattling and seal against draughts, Mighton Products are well worth a look:
In stately homes, the retired slave owners would have had shutters installed. I dare say they would have preferred secondry glazing had perspex been available.
I suppose they managed to keep warm in winter by throwng an extra African on the fire.
Pride and Predjudice aside, double glazing significantly increases the weight of the sash. Even replacing old glass in the units means adding weight to the counter-balances.
Actually, the livingroom windoes do have internal shutters (Which we use in the winter), but the upstairs ones are missing...
Ah yes ... And the other plan for the living rooms is to remove the ugly gas fire which sits in-front of the nice fireplace which has been boarded up with some ugly fireboard thing and put in a nice log burner which we were told it had some years back...
Thanks for all the replies so-far.
Gordon
Rick
I suggest you consider a pellet stove, look them up on google, and you will see what I mean, and there are grants for them too .....
Rick
Just for fun you might like to browse here
Complete waste of money and will undoubtedly spoil the appearance of your building - don't do it, have them properly serviced and they will last forever. The value of saved heating bill is just not worth the cost of double glazing as everyone discovers if they bother to do the calculations.
cheers
Jacob
Is it actually possible to "service" old sash windows?
I would imagine that in my early Victorian dwelling this would probably involve replacing all the windows, which would cost a fortune.
I've installed secondary glazing, which certainly reduces our heating bill considerably. It is reasonably unobtrusive, IMHO.
Yes, in many ways.
Depends, usu. much can be salvaged.
This is of *great* interest to me. Can you please tell me how, what, etc.?
Secondary glazing is probably OK when just installed but the big snag is that the gap isn't room sealed so warm, moist air gets in and condenses against the cold exterior glass. This pushes up the humidty in the gap and the moisture rots the frame...
You may think we'll open the secondary glazing when it's warm to ventilate the gap but you need to do that on every window, frequently. Realistically that ain't going to happen.
Whilst secondary glazing can be useful in the reduction of noise it is not generally considered to be thermally efficient.
As you will be aware, it is the air in a DG sealed unit that provides the heat barrier. The gap between the panes is critical, with 20mm being the optimum width with 4mm glass. Tests prove that as the gap increases beyond 20mm thermal efficiency reduces as convection inside the unit moves warm air from the inside pane to the outside, with the obvious outcome of moving cold air to the inside.
With most secondary glazing the gap between the panes is greater than
20mm and this heat transfer takes place. Add the potential problem with condensation that Dave L has highlighted and you have a "double whammy".A good thick curtain will reduce heat loss more than secondary glazing.
(I must add the rider that even SDG is better than only a single pane of
4mm glass between the warm fire and the snow outside) :)
I don't know what this means. I am quite sure that in my case secondary glazing did reduce heat-loss by a large amount.
I guess you are talking about a completely different scenario to mine. In our case there were fairly large gaps between the windows and the frames and one could feel the breeze on windy days. I imagine this would be the case in most buildings of this age - around 160 years.
Having tried that, I can tell you that it is nonsense in our case at least.
I imagine what you are saying might make sense when talking of a modern house but it really doesn't apply to a Georgian building with large sash windows.
Incidentally, our building is listed, and proper double glazing is probably not an option.
I looked into this, although not deeply, and the only services I could find were to completely re-make the windows. The frames of most of the large sash windows (there are 16 large sash windows and 10 smaller ones in this building) are slightly distorted, and about half the windows do not open fully without using force.
There are many very rich people (not us) with similar buildings in our neighbourhood, and none of them seem to have installed true double glazing, so I imagine it is not allowed.
I've used double glazing with frames made by Polycell. They no longer manufacture these, at least they are not available here. Basically, they fit inside the window frame, and are more or less invisible; most visitors do not realise they are there. There are 2 large panes (the sash windows have 6) and the middle bar coincides with the larger wooden cross-bars.
Before these were installed it was more or less impossible to heat the house; the present system is certainly not ideal, and there is still a large heat-loss, though I suspect that less that half is through the windows. (I would be interested to know if it is possible to calculate this.)
I'm not sure what you mean; but there is in fact no visible condensation inside the double glazing. I doubt if the air inside our secondary glazing is much warmer than the air outside, as the original sash windows are far from sealed.
Dublin - great city of Georgian buildings - there must be specialists in old building conservation in Dublin at least, though I know they are thin on the ground in the rest of Ireland. Try asking around City Hall or whoever it is with responsibility for conservation. Is there a Georgian Society or somesuch? Or a civic trust? Or ask local architects
- there will be at least one with specialist conservation interest who will know who to ask to do work. Generally it's going to be much cheaper to repair/conserve than to replace with some modern tat with built in obsolescence of 15 years or so like plastic windows. Properly maintained sash windows are reasonably draught free and if you do the heat loss calcs you will find that double glazing simply does not pay - there are lots of other heat conservation measures which are far more cost effective. More stuff on my site at
cheers
Jacob
| Do these things exist? I'm thinking of replacing our existing rattly | old sash windows with double glazed units, if they are avalable at a | reasonable price... | | There are (as usual!) complications: Notably, it's a Grade 2 listed | building, in a conservation area and inside the boundaries of Dartmoor | National Park... (So I'm already facing complications!) | | Any recomendations on a Devon supplier who might know about | these things?
When I did mine years ago Polycell produced some DIY secondary double glazing units especially for sash windows. If you search, someone probably someone still does it.
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