Does secondary glazing make much difference to noise?

[lemonpi]

I have double glazing, but am woken at night by aeroplanes. I’m wondering whether to get secondary glazing, but don’t know how much difference it would make. Would be great to hear anyone’s experiences of it!

I have it, but on single glazed buildings as the original windows aren't allowed to be removed in my house. I find it makes a BIG difference! My living room and bedroom windows facep onto a main road, my secondary glazing slides back to allow access to the blinds, for the few moments it's open the difference in noise level is really noticeable.

Single glazed windows* not buildings 🙄

Ah, that’s interesting! Thanks for that info! When you say it slides back, do you mean it’s a sash window style (or the horizontal equivalent of that, if you see what I mean? If I got secondary glazing, it would need to be with a vertical slider, like a sash window, as I have sash windows. I’m told that secondary glazing with sliding panes, rather than one pane covering the entire area, let’s more noise through.

Also, did you get any especially fancy/super expensive secondary glazing, or just standard (maybe with acoustic glass)? Thanks!!

Wondering whether anyone else has experience of secondary glazing?

I used to live in a flat with single glazing, on a busy road, and installing secondary glazing made a massive difference to the noise.

My ILs reinstalled their secondary glazing when they replaced their windows with double-glazing. They live on a not-very busy 40mph road. Cars are completely inaudible and you can barely hear passing buses and lorries. I don't know what it was like with just the double glazing, but I would have expected there to be some noise getting through.

However, where I live now had very poor, drafty double glazing. When we replaced the windows with better quality double glazing, we realised that the old ones had been letting in sound as well as drafts. So before you add secondary glazing it may be worth checking whether your existing double glazing is actually doing its job.

I put it in when I lived in an old flat with original Victorian windows. Made a massive difference to bo the sound and my quality of life. Regret not doing it years before!! Go for it.

I had a house with secondary glazing upstairs, the house was situated next to a military airbase operating helicopters. It made a massive difference to the noise and enabled the household to get a good night sleep when they were out night flying (which was frequently)

sliding sash windows are harder to seal where they meet. You can get a "furry pile" draught strip which allows one to slide over the other, but this is the weakest point. It is often notched to avoid rubbing on the flitch, but there may be a modern design that I don't know about. If there is a gap that a draught can get through, noise can penetrate, but a small crack will admit little. Some modern hotels have sideways sliding sashes, which seal together in the middle very effectively. It is quite expensive having a joinery works make up retro-styled sashes in odd sizes to suit an old house. Single large glass panes are less visible than small panes. Net curtains will hide them, if acceptable.

The tech of secondary glazing says that thicker glass is better for deadening sound, and that the secondary pane should be a different thickness from the original, as it will have a different resonant frequency. A deeper gap between the panes is better than a shallow one. I have been in older buildings with separate opening casements or french doors, opening inwards and outwards, which were excellent at deadening noise.

In some cases it is done with laminated or "bullet-proof" glass for added security. These are very heavy.

Yes. Listed house so not allowed to replace the single pane windows (and they'd be crazy expensive to replace too!) and yes it makes a great difference not only to noise but also to warmth.

Thank you so much for the replies - really helpful.

i have sliding sash secondary glazing with original 1880s single glazed sash windows. They tilt in for cleaning and slide up and down easily and block sound and cold. I think they are more efficient that double glazing as the gap is wider between the 2 layers of glass but I have nothing to compare them to but they definitely make huge difference that anyone would notice.

That’s really good to know - thank you! Particularly good to know that the secondary glazing makes a big difference despite being a sliding sash design, which is what I would need to get.

I have sashes at the bedroom windows, and a horizontal slide in the living room. The most obvious noise reduction is in the living room, but obviously bedroom is further from the road as higher up so not sure it makes a difference! Both styles have a "lock in" type fit, once they're sealed they're excellent.

It's a rented house and was done before I moved in so can't comment on the cost, but it really does work well here.

Hello, I have Georgian listed windows so couldn’t afford to update them. I got secondary glazing instead and it was AMAZING!
However that was from single glazed to secondary glazing. Not sure if that changes when you go from double-glazed to secondary glazed?

@Duxiejhrhrvjz That’s good to hear!! Is yours a sliding sash design, or non-opening, or something else, please?!

@UndeadSlut Thanks for your reply! What is a lock in fit, please?!

@Duxiejhrhrvjz I would be adding the secondary glazing to the double glazing, rather than replacing the double glazing, so hopefully it would make a difference!

I had single glazed sash with secondary glazing and I live on the A4. Noise was OK but it was drafty so I replaced the windows. I originally wanted double glazing and the secondary glazing removed but the company said that what I had inplace was better for noise reduction. Instead I paid for double glazing with soundproof glass, it wasn't cheap but its been worth it, I still get noise but it's greatly reduced and I have been able to get rid of the secondary glazing.

@Phillipa12 That’s interesting. I looked at one company that does soundproof double glazing - Hugo Carter - and they quoted £5400 for my bedroom window, which is a fairly small window! Is that the type of cost yours was, if you don’t mind me asking?!

By contrast, for secondary glazing with acoustic glass I was quoted £730.

(The quite for secondary glazing was from a different company.)

*quote

Nowhere near that cost. I used a local company and I had 3 windows replaced and a front door. The windows are now not full sash as that was too expensive but look like sash. The total coat was 4k, all the windows are 180cm by 160cm so not small.

To have the soundproof glass increased my bill by 1k, its not totally soundproof but much better than what was previously there. It did take 3 men to lift the glass panels as the outside panels were about 1.5cm thick.

@Phillipa12 Wow, that’s much more reasonable! Thanks for that info. I will look into whether there’s a company near me that does soundproof double glazing for that sort of price - it sounds worth comparing with secondary glazing.

On the front of my house I have acoustic glass on secondary glazing and double glazed casement windows. Can’t hear any noise at all. Much quieter than back of house which has just double glazed casement wooden windows.
The bigger the gap between secondary glazing to original window the better the noise reduction. We have wide window boards so it really works. If you don’t and it is very close to original window it becomes a pain to clean as well.