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

[R Philip Dowds (rpdowds]

All right, all right.  I've been staying out of this, but as a practicing 
architect, I will now pitch forward some tech info.  Sound management in 
residential structures has four components:

    (1) FUZZ:  Especially in large rooms accommodating many people having 
diverse conversations, FUZZ counts for a lot.  Carpet, curtains, tablecloths, 
upholstered furniture, and sound-absorbent ceiling tiles will all interact to 
diminish ambient noise and reverberation, making multiple conversations among 
small groups easier to handle.  However, FUZZ will do very little to mitigate 
noise transfer between different rooms, floors or dwelling units.  For that, 
you need ...
    (2) MASS:  From a sound transmission standpoint, your building should be 
built of concrete plank carried by cement block walls.  But you've built as 
wood frame (what a surprise!)?  In this case, there are some things you can do 
to add mass.  One of the best is about 1.5" of cementitious floor underlay, 
like Maxxon GypCrete, which does a dynamite job of dampening floor-to-floor 
sound transmission.  Needless to say, this has to be planned for ahead of time, 
and is not easily retrofitted once the building is occupied.  Now for your 
walls ...
    (3) DE-COUPLING:  Even with wood framing and drywall (inexpensive, but no 
mass), there are a variety of systems for mitigating sound transfer between 
adjacent  rooms or units.  One of my favorites is: Build a regular wall — wood 
studs with drywall on both sides — but then, to just one side of this wall, add 
some resilient metal z-track and one more layer of drywall.  This kind of 
construction "de-couples" the drum head, and significantly reduces sound 
transmission in both directions.  If you forgot the GypCrete, this same system 
can be retrofitted with good effect (and with money) to existing ceilings.
    (4)  BREACH PREVENTION:  Tiny cracks, seams, holes, or gaps allow vast 
quantities of sound to migrate, and can defeat the most carefully designed 
sound management construction.  One common example is convenience receptacles 
in the same stud pocket; sound will go into one box and come out the other, no 
matter how clever is the wall construction.

Note that I did not advocate strongly for sound batt insulation in the walls, 
which will help a little tiny bit, but not nearly as much as my other 
recommendations.

R Philip Dowds AIA
Cornerstone Cohousing
175 Harvey Street, Unit 5
Cambridge, MA 02140
617.354.6094


On Feb 25, 2012, at 12:30 PM, Bryan Bowen wrote:

> 
> Just a comment:  the technical detailing to solve these problems is very
> well established these days, so in new construction this should never be an
> issue.  
> 
> -b  
> 
> bryan bowen architects, p.c.
> 1510 ZAMIA AVENUE #103   -  BOULDER, CO  80304  -   (303)443-3629
> www.bryanbowenarchitects.com
> 
> 
> -----Original Message-----
> From: cohousing-l-bounces+bryan=bryanbowenarchitects.com [at] cohousing.org
> [mailto:cohousing-l-bounces+bryan=bryanbowenarchitects.com [at] 
> cohousing.org] On
> Behalf Of S. Kashdan
> Sent: Saturday, February 25, 2012 10:14 AM
> To: Cohousing-L
> Subject: Re: [C-L]_ Soundproofing between stacked units in cohousing
> 
> 
> Here at Jackson Place Cohousing in Seattle, Washington, we have some units 
> in our common house. Some of those units are located on the floor below our 
> common areas, and the soundproofing between the common areas and the units 
> underneath is not that good. The residents can hear people walking, chairs 
> moving, etc. We also have some units that are connected side-by-side in 
> other buildings. The soundproofing between them is also not that good. One 
> neighbor complains about hearing her next-door neighbor's children running 
> on the stairs inside that neighbor's unit. The stairs inside that neighbor's
> 
> unit have rug material on them. But, the sound of the children's feet 
> pounding comes through the wall. Another neighbor recently told me that she 
> is sometimes awakened by her next-door neighbor snoring... The sound comes 
> through the wall.
> 
> I think that every new cohousing community should put a lot of effort into 
> soundproofing for both making sure that common areas are comfortable for 
> people with hearing difficulties to be in and for giving people more quiet 
> in their individual homes.
> 
> Sylvie Kashdan
> 
> Jackson Place Cohousing
> 800 Hiawatha Place South
> Seattle, WA 98144
> www.seattlecohousing.org
> info [at] jacksonplacecohousing.org
> 
> ----- Original Message ----- 
> From: <rhmorrison [at] aol.com>
> To: <cohousing-l [at] cohousing.org>
> Sent: Saturday, February 25, 2012 8:06 AM
> Subject: [C-L]_ Soundproofing between stacked units in cohousing
> 
> 
> 
>  This is a tangent on Sharon V's recent posting about the very hard time 
> they had getting expert help on retrofit sound deadening for their dining 
> room.
>  For cohos that have stacked units (that is, one unit over another), how is
> 
> the soundproofing between these units? Here at Mosaic Commons we have two 
> pairs of stacked units and the soundproofing between the stacked units is 
> very poor. Sharon V wrote recently that there is a similar issue with 
> soundproofing between their stacked units (at Takoma Village).
> 
> Bob Morrison
> Mosaic Commons Cohousing
> Berlin, MA
> 
> _________________________________________________________________
> Cohousing-L mailing list -- Unsubscribe, archives and other info at:
> http://www.cohousing.org/cohousing-L/
> 
> 
> _________________________________________________________________
> Cohousing-L mailing list -- Unsubscribe, archives and other info at: 
> http://www.cohousing.org/cohousing-L/
> 
> 
> _________________________________________________________________
> Cohousing-L mailing list -- Unsubscribe, archives and other info at: 
> http://www.cohousing.org/cohousing-L/
> 
>