Possible to make some kind of faux secondary glazing using perspex?

ultimatenonhandyman · Post by **ultimatenonhandyman** » Fri Jul 16, 2021 7:36 pm

I want to do something for soundproofing about a window but it's large. Would it be possible to get some perspex and create some cheap kind of frame for it to go in to?

I'm just trying to come up with some ideas, so any comments and suggestions helpful.

kellys_eye · Post by **kellys_eye** » Fri Jul 16, 2021 7:54 pm

Yes, you can and yes, it does work (to some extent). It's not 'that' effective because you can't evacuate the gap (or replace the air with less dense gasses like nitrogen) so sound transmission is still there albeit reduced.

Downsides are the condensation between surfaces and cleaning it without scratching it.

Heavy curtains would work better for sound deadening - but in summer......????

big-all · Post by **big-all** » Fri Jul 16, 2021 9:44 pm

secondary glazing is very very poor unless it stops draughts
it needs to be easily removable for condensation and cleaning

Someone-Else · Post by **Someone-Else** » Fri Jul 16, 2021 10:31 pm

As I understand it, to deaden sound it needs to be absorbed by something soft (Curtains, foam on boards) rigid stuff like perspex will reflect it

big-all · Post by **big-all** » Sat Jul 17, 2021 8:29 am

yes heavy curtains or plant shrubs hedges and trees between sound source and window

Graeme from Tod · Post by **Graeme from Tod** » Sat Jul 17, 2021 9:07 am

It's probably best not to use perspex in a residential situation, it can be very nasty when it catches fire. ( I'm not totally current with this - there may be newer fire resistant variations ). Polycarbonate might be a better bet:

https://solutions.covestro.com/en/brands/makrolon

Both options will cost a few quid. Toughened glass might actually be a cheaper option.

The frame can be pretty simple, just four sides with a rebate routed out about 10mm wide & 1mm deeper than the thickness of the sheet that's going into it. Run a bead of silicone into the rebate & fit the sheet into it.

It might be easier to make two frames & join them - less cumbersome to manoeuvre around while you're fitting them. You probably won't notice the join if you line it up with the upright sections of your window frame.

Maybe you don't even need a frame - just screw the material directly to the window frame. ( Or figure a way to clip it on so it can be quickly removed in an emergency ).

I've no idea how well it will work as sound insulation.

ayjay · Post by **ayjay** » Sat Jul 17, 2021 9:52 am

A quick and simple solution for secondary glazing is "Easyfix". It's a U shaped plastic trim that fits around the edge of a pane of glass, use a sharp Stanley to mitre the corners (just the uprights on the U shape) and it remains in one piece and is then secured to the frame via small plastic clips resembling a simple turn button that fix with one screw, (when measuring, don't forget to allow for the clip to be fitted).

https://www.theplasticpeople.co.uk/easy ... y-glazing/

ultimatenonhandyman · Post by **ultimatenonhandyman** » Sun Jul 18, 2021 6:29 pm

Thanks all, very helpful.