Secondary Glazing

[Alex F]

I would like to improve the insulation of my sash windows. I have put in central heating in and I can see it going straight out the windows if you see what I mean - made worse by stripping some of the windows.

This is the house:


[Open Image] [Hosted by PhotoGalaxy.com]

I am not considering replacing them with double glazing but want a form of secondary glazing which is discrete and in keeping with the character. I would only use them in the winter months and would prefer a single sheet with a discrete timber surround. I would then just remove them (albeit cumbersome) and store them when the heat loss is not a issue.

The only secondary glazing I have seen is with PVC or metal. Do they exist in timber? Is there any reason why I can't get a joiner to make some which i would clip on in some way?

Would appreciate some advice or recommended firms. Thanks.

Alex

 

[Nemesis]

Have you considered having the windows draughtproofed instead by someone like Ventrolla? Or buying the kits and DIYing.

I doubt in reality that you are losing vast amounts of heat out of the windows, and draughtproofing and thick curtains (we have shutters too) can help considerably.

No reason why a secondary glazing sheet can't be installed for winter, but it might not be as beneficial as other measures could be.

You could look also at Storm Windows, which does fairly unobtrusive secondary glazing.

 

[Penners]

Is there any reason why I can't get a joiner to make some which i would clip on in some way?

No reason whatsoever, although I agree with Nemesis that the secondary glazing would be much more beneficial if the primary windows were draughtproofed as much as possible.

 

[Penners]

Ventrolla

Nem - do you have any idea of the approximate cost of Ventrolla's service? If they do everything listed here on a typical sash window, are we talking about a few hundred pounds, or what?

My son has a Victorian house in north London, with some badly deteriorated sash windows. If I can't find a reasonably priced renovation service for him, I have an awful feeling that I know who's going to end up doing the job!

Alex - I hope this doesn't count as hijacking your thread! The information might be of interest to you, too.

 

[Lime]

The problem with whole-window single-pane secondary glazing is that they are very heavy to move about.

 

[biffvernon]

This shows the fixing on some oak secondary glazing I made that hinges open.

It's quite a tricky thing to make secondary glazing that looks OK without resorting to metals and plastic but it can be done. And it does make a big difference to heat loss.

Of course you have to find a joiner who has spare time before winter.

 

[Nemesis]

My mate Plumber's Mate had her windows Ventrolla'd recently and is very impressed... not cheap but cheaper than the uPVC rubbish which her neighbours have had installed. What's the alternative?


Repair and draughtproofing is of course a DIY thing for those with the capability..

I am actually not so convinced that heat loss is as major as made out, and that alternatives to draughtproofing are cost effective.

 

[Penners]

you have to find a joiner who has spare time before winter.

And I imagine that joiners who can do stuff this nice won't have.

 

[NT]

Secondary glazing can be wood framed or simply frameless. With latches like Biff's a sheet of glass would need safe edges & some white foam strip, with further addons being optional.

Making a wood frame for your glass would not be difficult.


NT

 

[biffvernon]

The trouble is that you want a slim frame, which is then too weak to hold a large sheet of glass. Solution - use toughened glass so the strength is in the glass and the wood just gives it a nice edge. (Toughened glass has an added advantage that the edges are slightly rounded and don't usually cut your fingers when handled. So you could leave it frameless as NT suggests.) Toughened is more expensive but worth it on stuff you are going to carry about twice a year.

Yes, NT, the foam strip is a good idea. I use it to make a nice draughtproof seal, though you can't see it when the glazing is in place if there is a wooden frame. The draughtproofing effect of secondary glazing is significant.

 

[Lime]

I have used whole window secondary glazing before.
biffvernon's looks good.
It certainly puts a stop to draughts and substantially reduces outside noise too.

 

[Penners]

We have secondary glazing on most of our windows. It's sliding aluminium stuff (installed by the previous encumbent) - hideous but effective.

Wish I could afford the stuff made by the Vernon Corporation plc.

 

[Alex F]

Great responses. Thanks.

My house is in Guernsey so probably impractical to use UK contractor.

I have had many of the windows serviced as sash cords had gone but them will still be draughty.

The one shown in Bifferons is really what I had imagined and with toughened glass sounds an excellent suggestion.

I really thing that a large proportion of the heat in my house us lost from wondows and doors largely through draught. My walls are 3-4ft thinck so once the house is warm it is not escaping through them.

Bifferon, where did you get those pictures. I wondered if you have one of the whole window which I could see and print out?

Alex

 

[Penners]

I suspect that Biff got the picture out of his camera.

He's a window-maker.

http://www.biffvernon.freeserve.co.uk/intro.htm

 

[plumbers mate]

A bit late on this (I only use the Web at work when we are not manically busy and yetserday afternoon was super manic)
I was Ventrollad last Dec - not the best time of year to have your windows taken out.
Here are my memories of the event.
It was an average of £500 per window - but these are big and heavy - I can't even take them out to paint them which I thought I could manage easily (that's decrepitude rather than the Ventrolla's system's fault)
I am very impressed by them.
I used to have half the weekend Guardian stuffed in to stop rattles in even gentle breezes except that didn't work too well, bits got rattled out and the backyard would be littered with bits of Guardian after a windy night.
Over New Year when we had Gales I couldn't get to sleep because there were no rattles anywhere - it didn't seem natural. I stared at the curtains daring them to move, but instead of the continual sway which they had before, they were motionless.
My feet were still chilly, but that was a draft under the door and minimal heating, but the cold from the windows was greatly reduced.

The rep was very helpful and the lads doing the job were great - even supplied their own flasks of coffee.
The job was traumatic - no denying that - they did two windows per day, so took a full week. By the thursday morning I was badly traumatised at the mess of windows being planed and drilled and the eons-worth of soot and dust which spread everywhere. No where in the house was safe - rooms waiting to be done were unusable as I'd moved the furniture away from near the windows. I was told that I needn't have moved so much.
Apparently they usually set up a small workshop outside but as this was December I let them use one of the rooms for the work which is why it was so bad. I'm sure that with a garage or warm, dry weather the job would have been less messy.

The only thing is that I wish they provided a dvd of how to remove the windows because I am getting panicy that I've forgotten how to do it and they MUST be painted soon. I did suggest it to them though and may ask if there is anything.

A big warning though - after 25 years of windows that won't open (even though they rattled like mad) security becomes an issue - I have gone out and left windows open on a few occasions and was concerned at the low temperature in the bathroom one night - then realised the top sash was fully open - I go round opening windows just because I can!

 

[Penners]

Very useful info, PM. Thanks very much.

Did the £500 just cover draughtproofing, or did they also do things like renewing the wood covers over the counterbalance weight boxes?

 

[plumbers mate]

The job restored the windows - new sash chords, new cills where needed (so the smaller back windows cost more than the bigger front ones), any damaged beading etc that needed doing were redone, cracked panes were replaced with eastern european wobbly glass rather than modern characterless stuff. Any puttying needed doing was redone.
New lockable catches were fitted. I had original lifting hook things on the big sashes but they would have fitted them if needed. (they refixed one which had come out years ago and which I had saved for the day when I got round to doing it myself)
The £500 average was £400 for some, but one was £750 - it needed a lot of work - almost rebuilt I suspect.
Actually the average was really £570 - £5700 for 10 windows.
Any sanded down, new wood is primed but not painted. That's the first thing the Rep said "we don't paint".
(pity, they could subcontract to painters, I'm sure)

 

[biffvernon]

My house is in Guernsey so probably impractical to use UK contractor.

Yes, it's a long way off and they seem to speak a funny language. Here's the rest of that wondow:

Some might have preferred the frame to be painted white in this situation.

 

[Alex F]

Thanks Biffvernon. Very neat.

How do they attach to the main window frame at either end? I see the system used in between the windows. Is some sort of window lock bolt system used at the end sections to hold them in place?

(Apologies for numerous mistakes in last post - very careless!)

Alex

 

[biffvernon]

The centre pair are hinged so that they can open, so the whole thing is held up by a couple of hinges. The end ones are fixed - just screwed though into the old woodwork.

With big sash windows like yours it might be worth making them in a top and bottom half with a join at the meeting rail level. They'd be a bit more easy to manage then.