Replies

1. 
   DanH | Mar 22, 2015 09:12pm | #1

   The three techiques for sound reduction are mass, isolation, and damping.

   Mass means adding weight.

   Isolation means adding layers which are not (rigidly) connected together.

   Damping means adding (essentially rubber-like) materials which absorb sound and convert it to heat.

1. 
   kavu | Mar 22, 2015 11:59pm | #2

   Three techniques

   Thanks for the resonse.  I think what I'm really looking for are actual techniques that I can use to reduce sound transmission into the house.  For instance, is is easier to approach the problem from inside the house, or outside?  I've seen acustical panels for inside wall and ceiling  installs, but I am also wondering about other methods to reduce sound.  Thanks again.

1. 
   DanH | Mar 23, 2015 08:02am | #6

   Hypothetically (my only work in this area was in the early 70s on jet aircraft):

   You could apply something like fake brick to the outside.  The mass of the "brick" (assuming you used the "real" stuff and not plastic) would add needed mass, the irregularity of the surface would help disperse the sound, the mastic used to apply it would provide viscoelastic damping.

   You could laminate, say, 1/8" Masonite to the inside or outside, using a mastic that would remain slightly soft.  This would provide damping.  One would probably want to do 2-3 layers for most effectiveness.

   You could build another wall, separated from the existing by an inch or two (NOT using "studs" attached to the existing SIPs) and loosely stuffed with fiberglass.  This would provide isolation.

   But I have no way of knowing which approach would be most effective, or even effective enough to be worth the effort.

   (And, as others have said, windows are often the main route for sound conduction.)

2. 
   calvin | Mar 23, 2015 06:29am | #3

   Plumb

   how much glass is on the house?

   vaulted ceiling?

   roofing material?

1. 
   kavu | Mar 25, 2015 12:17am | #12

   Glass, Ceiling, and Roofing

   1 of the 4 walls is almost entirely double pane glass (~80% Glass)

   Vaulted tounge and groove ceiling

   Metal roofing over SIP

3. 
   hammer1 | Mar 23, 2015 07:20am | #4

   Dosen't make much sense, The foam in the SIPs is far superior to standard stud and fiberglass insulation for reducing sound. It won't do anything for your windows and doors, which will let plenty of noise through. Noise is one thing, shaking the ground is another. Jets and large trucks can shake the ground. 

1. 
   DanH | Mar 23, 2015 07:52am | #5

   Actually, foam is lousy at sound insulation -- too stiff, with very little damping -- and the way SIPs are constructed they're too homogenous and act like drumheads.

1. 
   hammer1 | Mar 23, 2015 08:10pm | #9

   Don't know how many houses you have built with SIPs but the owners of ones I have often comment about how quiet the house is. I've built many more conventional stud and fiberglass houses and many conventional with foam board under the sheetrock. I live in one I built in 1980. My house is extremely quiet, very energy efficient, too. Foam absorbs the sound waves so they don't carry through with any strength. I'm also a drummer. SIPs is the opposite of a drumhead but might make a nice practice pad. Foam is widely used for sound control. Less sound transmission is immediately evident when installing roofing or siding over SIPs, more so if you are in the house. 

4. 
   wmheinz | Mar 23, 2015 02:07pm | #7

   Compare to other nearby houses?

   Perhaps the first step might be to compare your house to nearby conventionally built homes.  I think you will find the SIPs house to be much quieter. 

   If it were me, I would first look at the other parts of the house...the windows, skylights, doors, ect.  They are much more likely to be the culprit.  We've done several structures that needed isolation from exterior noise...and low frequency sound like you describe is the toughest to deal with.  We've had acousticians recommend everything for using different thickness of glass in the insulated units to using a layer of laminated safety glass (has a plastic film between the two layers of glass - like car windshield) in one of the layers, to storm window type third pane that would add another dead air layer. 

   In addition...seal every possible entry place - spaces around the windows, duct work, exhaust fans, plumbing vents. spaces between the logs, all of the surface intersections (ie: roof to wall), etc - that will allow sound to move through the exterior envelope. 

   Beyond that, you will be getting into some major expenses to modify the exterior in some way...you could remove the roofing and install additional layers of material that would help further isolate the SIPs panels.  If you have a metal roof, you could remove it and install some other material with more density and weight,  But all of these seem a bit extreme for the intermittent issues you describe and would likey only marginally help - especially since you are now so aware of the noise. 

1. 
   DanH | Mar 23, 2015 05:48pm | #8

   Actually, if the problem is primarily low frequencies, adding structure to the SIPs to stiffen them would help.  Eg, wood or metal "ribs" every 3-4 feet.  The SIPs will act as a large diaphragm to low frequencies, and stiffening the diaphragm will raise it's resonant frequency.

2. 
   kavu | Mar 25, 2015 12:31am | #13

   Compare to other houses...

   We haven't compared locally, but we have compared sound from jets going overhead at our inlaws. We've noted the outside noise level vs. the noise inside with their convention framing techniques (2x4 walls built in the 70s, vs our 2x6 SIP built in the early 2000s), and our SIP house is always louder inside for roughly the same noise level outside.

   I think you are onto something with the glass.  We have a lot of it, and I understand it allows more sound through, compared to a thick wall - SIP or fiberglass.  But I don't see us reducing the number of windows as it would totally ruin our beautiful views, and modifying them would be very spendy since they are non-standard sized and very large panes.

   I agree we are looking at a major expense to work on the exterior, but we might have to bite the bullet because the noise is pretty distracting at times, and we really want to stay here.  It's a nice location.  Thanks for the reply.

5. 
   wmheinz | Mar 24, 2015 02:37pm | #10

   Definitive study on this exact problem
   Gotta luv Google. The following extensive study was performed because of excessive noise in SIPs houses next to a highway....There was a specific frequency range where they do not perform well. They made modifications that substantially reduced the sound transmission thru the SIPs...very interesting for any potential SIPs users...

   
1. 
   DanH | Mar 24, 2015 10:50pm | #11

   Yeah, that study pretty much demolishes the claim that SIPs are quieter.

2. 
   kavu | Mar 25, 2015 01:00am | #14

   Yes, exact problem with one catch...

   This is an excellent article.  Thanks for sharing.  My take away...  Add resilient channel to the outside of the house.  Insullate in between the channel with fiberglass.  Put OSB over the channel and fiberglass. That seems like a really good solution...

   Question:  Remember this is a log post and beam, and if we increase the thickness outside with resilient channel and then add OSB ontop of that, we may increase the thickness of the exterior wall so that it is wider than the log posts and beams, which are not only structural, but also part of the architectural appeal. As an FYI thickness of the outside wall could be about 1 inch thicker before it exceeds the produding logs. Looks like the OSB is 5/8, but I can't tell from the article how thick the resilient channel is.  Do you think this solution is still possible if I only have 1' to play with?

   Also, the November 2014 issue of FHB, #246, has an article by Martin Holladay on Air-Sealing SIP Seams, which made me think this would be a good place to post my question.  Could we get him or someone similar from FHB to weigh in here?

1. 
   DanH | Mar 25, 2015 07:35am | #15

   You could, of course, do a similar treatment on the inside.

   Or do something akin to their "plan B" treatment, which only adds about an inch.

   Or do the full treatment on the outside and add a "veneer" to the beams to maintain their "proud" appearance.