Soundproofing for walls and ceiling/floor

[coletteh]

Some suggestions for the following would be much appreciated:

First, we are moving an internal wall to widen one room and make another room narrower. As the rooms in question are a bathroom and a bedroom, we would like to make the wall as soundproof as possible. The rooms are upstairs. It is not a supporting wall, but simply a dividing wall, and therefore building a full-on metre-thick stone would not be an option (Wish it were though!) So, what would be the best options? Don't mind spending some cash if we actually achieve what we want.

Second, we have a bathroom on the floor above the kitchen and again we would like to reduce the noise that travels down to the kitchen (for presumably obvious reasons!). If it's relevant, the joists are old (maybe 100 years?). We currently have wood-effect laminate in the bathroom, although we plan to replace that. What would be the most effective way to reduce sound travelling down? Would a particular sort of flooring material offer good soundproofing? As we are working from scratch, we are open to all sorts of options - we could use ply, or chipboard, or laminate or proper pine floorboards, or ... in fact, we're probably happy to try anything except carpet.

All thoughts much appreciated. Many thanks in advance.

 

[Deluks]

For the dividing wall, build a staggered stud partition from 3x2 timber, on 4x2 baseplates. Fill the void entirely with rockwool slab insulation. Plasterboard both sides with 15mm plasterboard, or 2 layers of standard 12.5mm, with staggered seams. Then skim both sides.

Floor. Fill the floor void with rockwool, (be careful not to cover any light fittings) cover the floor joists with sheets of something, I'd recommend t&g flooring ply (not chipboard!). Then laminate with an acoustic underlay. Or vinyl.

Gaps around the edges and under doors will leak sound, so beware of this.

 

[coletteh]

Thank you Deluks for your very helpful reply. I note you specify 'not chipboard' -- what's the reason for this?

 

[Deluks]

It's crap! Especially in bathrooms, if it gets a soaking form a burst pipe or leaky tap, you'll be replacing the whole lot as it turns to weetabix. It's also not as strong as ply, you can punch holes in and break the corners off quite easily.

Ply is more expensive, if you can't track down t&g ply for flooring, then just use normal 15mm or 18mm WBP ply, which is durable. But cut the ply so that every edge sits over a joist, otherwise the gaps could cause sound leakage.

If you are planning on tiling bathroom floor, use 25mm ply.

 

[mikric]

Gyproc make a plaster product called sound coat, have seen it used on party walls , think it is only for masonary walls though but i could be wrong worth looking into though .