Noise-reducing windows

[ach5]

Hi all, I am looking for any advice / experience with options to reduce road noise by installing special glass.

The windows are deeply recessed, so gives me options.

I am considering two options, and would welcome any thoughts;

1) simply replace existing glass panes with special noise-reducing panes - it's a double glazed unit with 10mm thick outer sheet and I think 6 or 8mm laminated inner sheet (I.e two sheets of glass pressed together with a special noise reducing plastic film in between). The existing frame remains and that's UPVC.

2) leave outer frames & panes as they are, but install a second frame in the inside recess. For cosmetic reasons this would be a standard outside type UPVC window (not an aluminium secondary glazing unit which would require a vertical splitter bar up the middle). This second unit could have either normal glass or could have the special laminated glass, dependent on cost.

I haven't received quotes yet, and so the £ cost might make my mind up for me!



Option 1 would look better
Option 2 would be more guaranteed to cut down noise



So my questions are;

1) how much do the UPVC frames transmit noise? Would replacing the glass with the special glass be negated by noise transmission through the frames?

2) frames aside, how good are these noise reducing panes? Do they really cut road noise significantly? Or just a little bit?


Any other thought welcome!

[o u t a t i m e]

First let me say that I'm absolutely no expert on the topic. I'm just sharing my own experience.

I have a client in Zurich whose offices are directly on a very busy motorway. When the windows are open, the noise is deafening and you couldn't have a comfortable conversation in a meeting room. And the airplane noise from the nearby airport makes things even worse. When the windows are shut though, you hear absolutely nothing. It literally sounds like they achieve 100% noise insulation. It's incredible how well they work. It's a thick triple glazing (they look like three identical panes separated by a very small vacuum) within what looks like an aluminium frame.

I have never seen anything quite like it, including secondary glazing. When I moved into my current property, the windows were modern double glazed windows in PVC frames, but sound insulation wasn't great. So I added secondary glazing with stadip silence glass. It helped a fair bit, but still nowhere near those windows I saw in Switzerland. If I had to do it all over again, I'd go for some sort of triple glazing.

[raringtogo]

The trick to noise reduction is differing the strata material.
That way it cuts out various different sound waves as they try to travel through it. Having said that, kinda difficult with glass but varying thicknesses will help.
Also the distance between the original Windows and any additional greatly reduces the noise (air acts as a different material to glass) so the greater the distance, the better the insulation of sound.

Hope that helps some.

Si.

[MB2]

Not an expert but a friend got triple glazing due to cold wind off hills so that may be a better option or worth considering as they are very quiet too.

[stuie-t]

As mentioned above, you want a big gap between the panes of glass, so secondary glazing is more effective at noise reduction that sealed double glazing generally. Perhaps regular double glazing with secondary glazing might be the answer though!

[leahorsfall]

I work for a double glazing company and we do both options #1 and #2 and we also do triple glazing......secondary is the most sound proof followed by triple glazing followed by different pane widths (inhibiting resonance)......

The technical details are in the Anglian website which is anglianhome.co.uk.....sort I don't know how to post links PM me if you want any more help

[ach5]

Thanks chaps, so the clear answer is some form of secondary glazing would out perform simply putting a special laminated pane in the original units, so I think that's what I'll do.

[Chabsy]

Its complicated but triple glazing with 3 same thickness layers wont work as well as stadip silence.

It is good to talk to people who know what they are talking about rather than getting internet opinions

http://www.secondaryglazing.org.uk/

They are in london but you dont need to tell them that.

[Lowejackson]

In addition to the above comments I would also suggest the quality of the fittings will play a huge role. In a lot of cases plastic is used to cover up the small gaps in the installation for visual and domestic acceptance, this is normal but when you are chasing noise reduction a small hole will make a big difference.

I would also be tempted to have a look at various solutions for windows in sound recording studios. They may be able to offer some inspiration. If you intend to keep the original windows then make sure they are fully sealed and all the neoprene (or similar) seals are in good condition with no gaps at all

[jmarchitect]

I concur with Lowejackson above. Making sure the fit between casement and frame is sound and free of deformed weather strips and draught seals is the first step to reducing noise. The next thing to look at is secondary glazing. There are versions that simply fix to the inside with magnetic strips and are made with upvc edge trims and polycarbonate sheets and aluminium or upvc framed inner casements that offer an easier way to open the inner casement without having to lift off the inner casement. Replacing the existing sealed double glazed units with supposedly 'sound reducing' sealed glazed units is unlikely to provide a marked improvement and will be an expensive option.

[ellomoto]

Spent ages writing loads of rubbish lol

DONT use triple glaze it can give huge problems with road noise.

Before you do any replacements 1% incompleteness will result in 98% reduction in efficacy, an hour with a tube of silicone could make a bigger difference than anything else!

As others have said secondary will give biggest £ for £ improvement. Try to get Guardian Lami Sound Control glass it is slightly better visually than Stadip Silence and chances are you will then get Guardian Low E glass that is much nicer visually than Planitherm that will come with the Silence.

I would imagine the 10mm & acoustic laminate units are very costly if they are doc L compliant.

[leahorsfall]

Thanks chaps, so the clear answer is some form of secondary glazing would out perform simply putting a special laminated pane in the original units, so I think that's what I'll do.

Also.....do your existing windows have trickle vents (the slots at the top)
My company refuse to fit our laminated outer pane product where trickle vents have to be refitted.

If you have trickle vents and take the old windows out they will have to be replaced with new windows that have trickle vents in them.....this makes triple glazing and laminated outer panes of SIGNIFICANTLY less value as a sound reducing excercise!!

Incidentally there is a grant that has been awarded to anyone living within a certain distance of parts of Heathrow airport for sound reduction and Anglian is the exclusive supplier for it.....

[series5]

Just be a little careful:

there are several elements to a double glazing system - two most obvious being the glass and the frames.

There are various forms of acoustic isolation glass materials and I'll skip over these.

With frames, by far the biggest contributor to passing noise is air gaps either around the frames or between components such as the sashes and the frames themselves.

A lot of people try to reduce noise and drafts by simply plugging all of the gaps. However, glazing systems rely upon a certain amount of natural ventilation to keep condensation low. This is the principle of the trickle vent.

If you upgrade all of the wedge gaskets, close over trickle vents, change the rubber sash gaskets for, say, QLON and renew all of the hinges you will reduce noise but you will introduce a host of other issues instead. Some of these are down right unhealthy (mold, condensation, etc)

Double glazing, from an engineering perspective, is very much a balancing act - maximise one objective and it has a detrimental affect upon another. Double glazing salesmen never admit to that and simply focus upon factors that they think will get a sale.

[switch107]

Option 1:
Noise isolation you can achieve by different thickness of glass panes (eg. 10&6mm or 10&8mm). Additionally as internal pane use laminated glass with noise reduction foil. 44.2 laminated glass with acoustic foil will do job. Such combination of glass has on the top of my had noise reduction 59dB. It would be recommendation if you leave at the front of motorway and over a head you landing tunnel for airplanes. Reduced space to 12mm increase sound isolation but reduced energy efficiency. Frame doesn't matter. Sound is transmitted by resonance of glass and by differentiate thickness you differentiate resonance frequency.

Option 2: waste of money but highly recommend by all glass/windows sellers

[leahorsfall]

Just be a little careful:

there are several elements to a double glazing system - two most obvious being the glass and the frames.

There are various forms of acoustic isolation glass materials and I'll skip over these.

With frames, by far the biggest contributor to passing noise is air gaps either around the frames or between components such as the sashes and the frames themselves.

A lot of people try to reduce noise and drafts by simply plugging all of the gaps. However, glazing systems rely upon a certain amount of natural ventilation to keep condensation low. This is the principle of the trickle vent.

If you upgrade all of the wedge gaskets, close over trickle vents, change the rubber sash gaskets for, say, QLON and renew all of the hinges you will reduce noise but you will introduce a host of other issues instead. Some of these are down right unhealthy (mold, condensation, etc)

Double glazing, from an engineering perspective, is very much a balancing act - maximise one objective and it has a detrimental affect upon another. Double glazing salesmen never admit to that and simply focus upon factors that they think will get a sale.

Much of this is true.....if you have air bricks then sealing up trickle vents shouldn't be a problem.....

Q-lon gaskets are really I better than neoprene ones. Everest do q-lon and have an "effective air leakage" of more than 0 which means they generate a draught!

[ach5]

Option 2: waste of money but highly recommend by all glass/windows sellers

Really?

This goes against some of the comments above.

I am beginning to feel that a second full windown frame unit fitted into the recess will be better at sounds reduction than just replacing the existing frames glass with stadip, though it might not look the best. For various reasons, if I do this, it wont be the metal "secondary glazing" units you see, but a full UPVC frame fitted about 12" back from the main window, within the deep recess.

[Mr.D]

Had secondary glazing fitted to the original victorian sash front windows in my previous house.
Benefits were no visual change to the exterior of the house or modification to the sash windows (secondary frame fitted around them).

Noise isolation was mesmerising , wished I'd had it done years ago.

[stooo]

Thick secondary glazing. Works wonders.

[soundood]

just brick up the windows, its the only way to be sure.

[treebirch]

I have triple glazed windows that don't have any kind of noise reducing system incorporate but they do reduce the noise significantly. It was an option however. I am lead to believe that although the glazing unit is critic to this the frame also pays a large part, making sure that the seals are 100% and that there are 3 or more sealing beads around the window. If you can take a look at some of the German a Scandinavian manufactures, they are decades ahead in terms of technology than the UK.

[leahorsfall]

Order of usefulness
1 Secondary (faffy)
2 triple (Anglian do a draught pruf version)
3 laminated outer pane
4 normal double