Sound proofing recessed window, (plasterboard sheets?) - please help.

[danton133]

I want to sound proof a bedroom window from loud road noise as much as possible (I don't need to see through the window).

Sound is not really coming through the walls since they are thick stone (it's an old building).

Window is about 1.2 meters square, and has a 0.5 meter interior recess.

Solutions would need to be temporary/removable.

From the research I've done possible options include; drywall/plasterboard or OSB board cut to the size of the recess and stuffed in, or acoustic/sound blocking blanket (with mass loaded vynl) draped over the window or fitted to the interior wall and covering the recess.

I'm drawn to the drywall option, using multiple layers, but I've read it requires insulation foam between the layers to work, I can't see how this would be possible though and hoped I could just use multiple layers (3, 4 or more?). Also I'd read it's not great for low frequency road noise, this true?

My budget is around £150/$200.

 

[Alice of Old Vincennes]

Acoustic panel

 

[Dunring]

Quietrock is a gypsum drywall that absorbs 7 times more noise than regular drywall. I've used it and it works. Closing off a window might just take 1-2 sheets.

 

[napfkuchen]

I faced the same problem a few years ago. As a measure, the windows in two rooms were replaced with triple-glazed ones with insulated roller shutter boxes. I also installed an additional “inner roller shutter” in each room. Before going to bed, I filled the space between the window and the interior blinds with foam blocks cut to size. I also experimented with an additional heavy curtain, but there was no positive effect. I think it's because the low frequencies can't be dampened so easily. After that I gave up, quite disillusioned, and resorted to ear plugs/NC headphones.
It was all very expensive, time-consuming and labor-intensive with pretty sobering results.

 

[sergeauckland]

A 100x50mm wooden frame, covered in two layers of gypsum board (Quietrock or equivalent is a good idea), separated by around 100mm and the cavity filled with rockwool, will make a removable one-piece solution. Just make sure that you caulk between the frame and the window recess, as even the tiniest of gaps will allow more sound through than the rest of the window. As your recess is quite deep, you can space the frame from the window and fill that cavity with rockwool.

Alternatively, and I know you said you don't need to see through the window, is to fit a sealed double-glazed unit at an angle to the main window, with a further single sheet of glass vertically, so you have two angled cavities. Again the edges must be completely sealed and the glass must be very clean inside as otherwise fingerprints will just irritate the hell out of you!

I've done something very similar to soundproof our local radio studios, in our case it's as much to keep the sound in as out.

Edit: If the room is upstairs in a conventional British two storey house, one issue will be the sound coming down through the ceiling from the loft space, and bypassing the window altogether. Very heavy loft insulation will help, but that won't do a lot for very low frequencies, but then very little does, except mass.

S.

 

[danton133]

Interesting, thanks guys. Im now thinking about making a removable frame and using weather stripping to plug the gaps although I had not thought about sound from the ceiling. I'll have to get up in the loft and have a listen to see how loud it is up there.