soundproofing

starving_artist

Any idea if floor-to-ceiling built-in bookcases filled with books on either side of a chimney breast would be (as) effective as building a soundproofing wall in the alcoves in reducing noise (mainly voices) from next door?

Grenage

Possibly; mass is best for blocking noise.  It's impossible to know how effective either would be as retrospective sound insulation is a tricky business.

princeofpounds

No, but it could be effective. 

Sound is disproportionately transmitted through gaps in insulation. So for example, if you have a wall that is 99% closed and has a hole that takes up 1% of the area, you'll be able to hear quite clearly through it, 99% of the sound will not disappear!

So in a bookcase; anything covered by the books should be very effective insulation, but unless it's well-designed there will be some gaps in the books.

Also, multiple layers of different materials are more effective than a single layer (different resonance and acoustic mass, reflections of sound energy from material interfaces). So a bookcase with closed cupboard doors would be much better than a bookcase. Or a bookcase with a full layer of insulation, even if thin, behind it.

This is all for airborne sounds, which seems to be your issue - vibrations along structures are harder to deal with. 

saudimick

Is there any grants for soundproofing home from road noise?

FaceHead

It seems unlikely that a bookcase is going to be nearly as effective as materials designed for their acoustic properties. As above, getting a proper seams is crucial - you'll get this from e.g. acoustic plasterboard skimmed over, but books are unlikely to give you a nice seal. 

Better than nothing of course, and you might need somewhere to keep your books. 

FreeBear

Used to have shelves filled with books either side of a chimney breast here. I disposed of the books & ripped out the shelves a few years back when renovating that room. Anecdotal observation - There does appear to be a little more noise audible through the wall. So yes, I would say that a wall full of books will reduce noise transmission a little, not that I would go out and buy a pile of books just for that purpose.

Sandtree

Depends exactly what you are trying to achieve, stopping the neighbours noise coming into your room? Yours into theirs? Improve the sound quality in yours?

Floor to ceiling bookcases full of books will certainly help, you could look at low profile solutions to put behind the bookcases to further help. I know some in home cinema crowd swear by something that looks like heavy rubber matting and a specialist glue to attach it... looks ugly but fine being a bookcase