Can I use floor underlay to soundproof a room?

Make sure it's fireproof!

There is a product called Roxul Safe N Sound, which is a mineral-wool insulation product that is fire-resistant.

Roxul is good stuff but, needs to be put i the wall. Its easy to cut and install but, has to be put in the wall. Thanks....

Hi Ellis,

You could line your walls with Self extinguishing Polystyrene and panel over it.

There are two kinds of acoustical remediation: reverberation/absorption and sound transmission.

Upstairs sounds like it needs reverberation and absorption solutions. Ideally, upstairs needs to have the STC ( sound transmission coefficient) reduced there as well. Stop the sound from leaving the room.

Homosote Panels are the best solution for this problem.

You will find Homosote’s website quite interesting as they are The Source for pros who design sound booths, auditoriums and concert venues.

I specify their “systems” on some of my architecture projects.

Homesote panels.

You have a number of DIY, cheap options. One is Mass Load Vinyl (MLV).

https://www.google.com/search?q=Mass+loaded+Vinyl+(MLV)+for+sale&rlz=1C1SQJL_enUS800US800&oq=Mass+loaded+Vinyl+(MLV)+for+sale&aqs=chrome..69i57.3110j0j7&sourceid=chrome&ie=UTF-8

Other options include hanging packing blankets, soundproof curtains, bookcases against the wall filled with books,

https://soundproofliving.com/list-of-sound-absorbing-materials/

https://www.wikihow.com/Build-a-Sound-Proof-Room

https://www.amazon.com/12-Acoustic-Panels-Studio-Wedges/dp/B00TP7C9YY/ref=as_li_ss_tl?creativeASIN=B00TP7C9YY&imprToken=hqIM3v6gbJe1v8jL9Yv.qg&slotNum=1&s=musical-instruments&ie=UTF8&qid=1529848886&sr=1-4&keywords=soundproof+foam+panels&linkCode=w61&tag=soundproofliv-20&linkId=aba841f3aef422511927501deba04d8e&language=en_US

https://homeguides.sfgate.com/soundproof-wall-cheaply-43537.html

You can also have insulation blown into the specific walls.