Cohousing-L Mailing List: Re: Soundproofing between stacked units in cohousing

[Sharon Villines (sharon]

On 25 Feb 2012, at 11:06 AM, rhmorrison [at] aol.com wrote:

> Sharon V wrote recently that there is a similar issue with soundproofing 
> between their stacked units (at Takoma Village).

I'll add one thing. Most of the sounds we are aware of dampening are dampened 
by soft surfaces. But in my limited study of acoustics I learned that hard 
surfaces transmit sound and that it is the beams between the stacked units that 
need attention too. If I put insulation between my ceiling and the floor above, 
some noises would be dampened but other noises would not.

What helped a lot was people purchasing furniture, which was done over the year 
or two years after move-in. The noise at first was incredible.

Rugs help because sound is most easily stopped at the source. The heavy 
furniture helped stop the vibrations moving through the beams. 

The solution I found would have meant tearing out the ceiling and putting what 
I can only describe as braces between the beams. It's a manufactured system — 
not just installed by a carpenter — but I've forgotten the name. 

The more you can do before you move-in the happier everyone will be. The 
average construction grade, and we supposedly had better than average, means:

1. Heavy walkers will be heard every time they walk and you will know when they 
have had a bad day.
2. Running children, even babies, will sound like heavy walkers running fast.
3. Two running children will be like a percussion orchestra.
4. Dropped cans, dishes, containers of silverware in the kitchen will be sharp 
whaps.
5. Active lovemaking in the middle of the night will embarrass someone.
6. Sliding closet doors will be like chalk on a blackboard.
7. If you like to fight in the bathroom, don't. The hard surfaces, like 
porcelain, reflect more sound.
8. Don't lift weights or run laps at home.

This sounds horrible which it isn't. No one does all these things at the same 
time nor is everyone home to hear them at the same time. But I do live in fear 
that a child will move in upstairs and that my downstairs neighbor suffers when 
children visit me, as they often do.

Sharon
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Sharon Villines
Takoma Village Cohousing, Washington DC
http://www.takomavillage.org