Insulating Loft Soundproofing


New Member
Hey Folks,

Hope you are well.

I have alot of noise coming from the neighbors property through the loft and back through the ceiling into my bedroom. I am therefore wanting to insulate the loft and have been advised by an acoustic company this would be the way forward, as this is a weak spot.

I am going to use this form of mineral wool insulation, Knauf Earthwool Loft Roll 200mm. Does anyone know anything else i can combine with this such as carpet underlay or anything further that might help to reduce sound further? I have heard that QuietFloor Plus carpet underlay is good for sound reduction, can i lay this on the loft ceiling joists to hopefully help with sound travelling?

I am also going to use Green Glue Noiseproofing Compound, for any holes i find in the brickwork on the wall at the back of the loft that connects to the neighbors property. Is this sealant okay, or can anyone recommend anything better?

Thanks very much for all your help. I look forward to replying to your posts soon, as ideally i want to start this job in the next 7 - 10 days.

Many thanks,


new build inspector

snagging inspections 01788 494400
sound insulation problems

Hi paul

Building regs require 2×150mm cross layered mineral wool or equiv ....
So your additional 200mm would make it very toasty but have little effect on the noise

The problem with most mineral wool installs is the intersection of the roof and the wools...often the detailing is poor
And this where heat losses occur

Remember that the mineral wool is not designed to be an accoustic layer

Most noise comes through 'ventilated soffits in my experience

Yes there are accoutic mats or layers you can install ..and i am sure that they will help if fitted well and between trusses


New Member
There are insulation batts which are highly compressed insulations which do assist reduction in sound travel. A little heavier than the normal rock wall and more expensive and being compressed to not take up the loft or ceiling volume. I did
use acoustic layers in addition which is heavy to lay. Defiinite sounds reduction for the investment however the sound reduction on the compressed rock wool gets less impressive the higher the sound deadening level used ie choose the best deadening level for the buck invested.