Sealed units - maximising sound insulation properties

Dear Group,

I am in a situation where I need to minimise sound transmission into a room (noises such as sirens and raised voices, not low frequency or road noise).

There is no option of secondary glazing due to the fact that there is a Juliet balcony. The only option is 'upgrading' the existing 24mm (4-16-4) sealed units. I appreciate this is not the ideal option.

So, what is the ultimate 24mm sealed unit for sound reduction?

Different thicknesses of laminated glass? Gas filled? Sound insulating spacer bars?

Many thanks for any advice/experience that anyone can share.

Regards,

Alex

Reply to
youmustguess
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I don't understand that. Secondary glazing goes *inside* the existing windows.

Any difference is likely to be negligible and wholly out of proportion to the cost expended. Secondary glazing is what you need.

Owain

Reply to
Owain

The thickest glass possible with the greatest gap.

Reply to
Dave Plowman (News)

I believe it's best to have several inches of space between the panes, also to have them not quite parallel to one another, to avoid standing waves in the space.

Reply to
Frank Erskine

Also, bear in mind there may be trickle vents letting sound in, in which case improving the glazing may not help. Simon.

Reply to
sm_jamieson

Presumably it's because due to the Juliet thingy, the windows are casement-type, opening inwards, so if the OP wants to ever open his windows again, secondary glazing is out (I've only ever seen sliding or fixed secondary glazing).

David

Reply to
Lobster

Comprehension dawns. Another reason to dislike those Juliet tings then.

It might be possible, if the opening part is less than half the width of the window, and the sliding is carefully arranged.

Hinged sec glazing is obtainable, I've seen it, or could be made up with wooden frames.

Owain

Reply to
Owain

In article , snipped-for-privacy@hotmail.com writes

Pilkingtons had some great pages on their Asia/New Zealand site with tables of construction vs attenuation but the page is no more.

From memory, the best of the DG options was 6.4mm laminated inner,

4mm plain glass outer with appropriate spacer to make finished thickness, the dissimilar glasses broke up resonant transmission. I think the claimed reduction was 50%+. I see Pilks have introduced Optilam Phon which claims to absorb more sound by having a softer plastic layer than that of normal laminate so that would probably be the ideal inner.

There may be more info at

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but they don't half make it hard to find. If it bothers you I imagine they will do Optilam Phon in low-e as well. Be sure to buy from/as trade if you can.

As I'm sure you're aware, the window seals will need to be pretty airtight to get much of an improvement, if the noise doesn't already reduce by a dramatic amount as you close the window the last 5mm & latch it then you probably have a suspect seal.

If you have trickle vents, forget it unless you fancy filling them with builders' foam.

Reply to
fred

In article , fred writes

Ah, here we go:

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are 16mm gapped but I'm sure 6.8/12/6 would be just as easy to have made up.

Reply to
fred

Interesting that the total thickness of the glass is the important thing - it makes little difference if this is made up of a single or double glazed unit, sound wise. Unlike secondary glazing the width of the wall away from the main which provides a very real improvement.

Reply to
Dave Plowman (News)

Dear all,

Many thanks for the various replies.

Lobster was correct in the assumption that the Juliet balcony consists of (large) inward opening casement doors, making secondary glazing impractical.

I have already replaced all the suspect seals and there are no trickle vents, so I think the next step is to get a few quotes for the cost of new sealed units featuring the Pilkington glass mentioned. I'm sure it will be eye-wateringly expensive!

Many thanks again,

Alex

Reply to
youmustguess

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