Sound Insulation in between joists and studs

[Jupiter01]

Hi All,

I am renovating my place and as part of this, ceiling boards are coming down and there are a few new partitions separating bedrooms. I thought that it was a good opportunity to introduce some sound protection. I have done some research and can see that there are extreme lengths (and cost) that one can go to. I can't afford this but would like to know what is sensible and effective in my situation.

I have already decided that i will use sound boards on the studwalls so the question really relates to what I stuff the stud walls and floor joists (separating upstairs and downstairs) with. I can see that there are special sound slabs too but the other option seems to be to use loft insulation and pack out the voids with this. I appreciate that this may not be as effective but I am unsure on the cost v value argument.

Thanks in advance.

 

[endecotp]

You could look at what the building regs require for new builds, as a guide. For example, for internal walls they say either:

(A) min 2 layers plasterboard of density at least 10kg/m^2 each side, min 75mm studs, no insulation.
(B) min 1 layer plasterboard of density at least 10kg/m^2 each side, min 75mm studs, and min 25mm of mineral wool with a density of at least 10kg/m^3 (i.e. "loft insulation").

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/468870/ADE_LOCKED.pdf
Section 5.

You can find their requirements for floors & ceilings there too.

If you want to improve on that you need to maximise the mass of material, so regular loft insulation will be significantly less effective than acoustic insulation; typical densities are around 12 kg/m^3 for regular vs. 60 kg/m^3 for acoustic. One alternative to acoustic mineral wool is wood fibre batts. I've not looked at proces recently.

You will quickly reach a point where doors, cut-outs for sockets and switches, and details at floor/wall junctions, become more important than the main construction.

Good luck!