Soundproofing solutions please?

viki83viki

Hi,

we live in an old Victorian house that some years ago had the basement level converted into a separate flat. They were always owned by the same people until we purchased the house part 6 months ago.

The sound insulation between the 2 units is terrible! We can hear conversations, doors closing etc, not to mention loud music on the occasions that they have parties. It is currently empty and we have a key so experimented and found that they can hear pretty much every footstep we make - who knows how much of our toddler's noise is inflicted on them as she runs around and drops things etc.

What is our best option for soundproofing, does anyone know? We will probably only do our lounge at this stage, as that is over their lounge and hallway. It is about 19 square meters.

We were thinking that we would need to get up the floor to put something down between the joists? Also, we presume that changing our laminate floor for good quality underlay and carpet will help both us and them?

Thank you in advance!

Viki.

cyclonebri1

You need to thicken the walls, by adding a secondary wall if there are no fillable voids already. All cavities need to be closed and filled to achieve what you desire

Yep, exposing the joists and using a superior insulator, not rockwool etc, will be needed.

Carpet is always quieter than a hard surface, also adds a degree of sound proofing from indirect vibration.

andycrichton

A sound proofer explained to me that retro fitting is not exactly pointless but unless you have very deep pockets, don't go too much beyond carpet and underlay, because sound travels through joists and down the walls they are connected to and - a bit like leaking water, unwanted sound is cleverer than most humans.

viki83viki

We have solid granite walls, so no voids to fill?! (There may be some in one of the internal walls which we think is stud, so will look into that once we move some kitchen units.

Andy, that does make sense. I am guessing we have a fair space between their ceiling and our floor, and also, we found these things online that you lay over the joists before putting your boards down, and they absorb any impact shocks etc and then also a membrane you can put down over the floorboards and then seal in with acoustic sealant. Would this get around these issues? Perhaps we need both of these as well as the acoustic insulation stuff between the joists?

I would just rather do it properly now than take short cuts and then wish we had done more later on. If Im getting up the flooring I only want to do it once.

NewtoDIY

The only materials that are suitable for sound-proofing are extremely dense and very heavy also. Sound travels like water so you have to fill all gaps, otherwise it will just find the path of least resistance. If the noise issue for you is underneath, then you need to build a raised floor. Presumably in a Victorian house you have lots of ceiling height so it's not going to be too noticeable.

That's the way that professionals in the acoustics industry would deal with this. You'd probably need to involve a structural engineer and builder, and you'd be looking for extremely high density flooring, then some kind of acoustic sealant at the seams. You could do one room at a time for sure.
If it's that annoying, then it is worth doing it.

Norman_Castle

As you have access to the flat below putting damping on the door frames to lessen the noise is cheap and effective. Foam draught excluder or similar will work. Fitting a floating ceiling in the flat below could be very effective.

hamster2013

not sure what these type of solutions are worth
maybe get a quote from one of these 'thin' acoustic walls and have it tested in one room first
http://www.noisestopsystems.co.uk/thin-wall-soundproofing