I have not looked into the sound resistance of steel SIPs so I cannot comment on the sound resistance of steel SIPs.  Apparently, it is a known fact by SIP manufacturers, suppliers and installers of OSB/EPS SIPs that OSB/EPS SIPs have been documented by scientific tests to have low resistance to sound transmission.  Below are two links to scientifically backed documentation on the sound resistance of OSB/EPS SIPs from two different manufacturer's websites that show the actual sound resistance/STC (Sound Transmission Class) ratings OSB/EPS SIPs.  Both of these SIP manufacturers are well known in the industry:

http://www.pbssips.com/Tech%20Bulletins/Tech%20Bull%2025a%20sound%20trasmission.pdf

 

http://www.rcontrol.com/downloads/brochure/RControl%20SIP%20Testing%20Summary%20Chart.pdf

One of the SIP manufacturers indicates that their SIP has an STC rating of STC 28 when finished with ½” drywall.  The other SIP manufacturer indicates that their SIP has an STC rating of STC 29 when finished with ½” drywall.  The manufacturers’ tests are backed by ASTM standard E90.  This ASTM test method covers the laboratory measurement of airborne sound transmission loss of building partitions such as walls of all kinds, operable partitions, floor-ceiling assemblies, doors, windows, roofs, panels, and other space-dividing elements.   

 

After considering the information above, note that the APA and other sources describe the sound resistance of STC 30 as “Loud speech can be understood fairly well.”  See APA Noise-Rated Systems Design/Construction Guide, form number W46ON at www.apawood.org for more information on STC ratings and ASTM E90.  There is more information on this subject in my June 5 post.  Here are descriptions of the sound qualities different STC ratings as described in the APA document I referenced above:  

 

STC 25            Normal speech can be understood quite clearly.

STC 30            Loud speech can be understood fairly well.

STC 35            Loud speech audible but not intelligible.

STC 42            Loud speech audible as a murmur.

STC 45            Must strain to hear loud speech.

STC 48            Some loud speech barely audible.

STC 50            Loud speech not audible.

 

“Normal speech can be understood quite clearly” and “Loud speech can be understood fairly well” perfectly describes my experience with exterior SIP walls without added soundproofing measures.  You can only imagine the potential for lack of privacy, noise from a highway, barking dogs, etc. if you have not experienced it for yourself.

Choward;

an 1-1/2" hi-hat furred space solves the problem

It would be good if the SIP industry would inform people of the "problem" before people make the decision to build with SIPs.  Obviously, the problem is not easily solved in a SIP home that has already been completed!  

I think that SIP manufacturers, suppliers and builders should publicly provide a clear and direct comparison between the sound resistance of traditionally framed construction and the sound resistance of SIPs (including actual STC ratings), an explanation of the meaning of an STC rating, an explanation of the significance of a low STC rating and descriptions of the measures that need to be taken during construction to compensate for the lower sound resisitance of SIPs.

Posted By choward on 29 Jun 2010 12:28 AM
It would be good if the SIP industry would inform people of the "problem" before people make the decision to build with SIPs.  Obviously, the problem is not easily solved in a SIP home that has already been completed!  

I think that SIP manufacturers, suppliers and builders should publicly provide a clear and direct comparison between the sound resistance of traditionally framed construction and the sound resistance of SIPs (including actual STC ratings), an explanation of the meaning of an STC rating, an explanation of the significance of a low STC rating and descriptions of the measures that need to be taken during construction to compensate for the lower sound resisitance of SIPs.

what is the STC rating of traditionally framed construction?

R-Control has the only published STC ratings for SIPs that I have seen (STC 29 with 1/2" drywall and 39 with resiliant channel and 1/2" drywall).  http://www.achfoam.com/ACH/media/do..._Chart.pdf

Based on the STC ratings I see at http://www.toolbase.org/PDF/CaseStu...atings.pdf  A SIP wall structure appears to be less sound resistant than a standard frame wall.  The STC rating of 29 is about the same as a single sheet of drywall by itself (1/2" drywall STC 28).

It would seem a standard SIP structure would be louder than a standard frame structure and much louder than a block or ICF structure.  I would assume the reason many SIP owners comment on their house being quieter is because the SIP structure is tighter than standard frame construction.  Meaning there would be less small openings where noise could bypass the wall structure.

I would be interesting to get an STC rating for steel SIPS with the high hat furring.  Since high-hat wouldn't provide as much decoupling as resiliant channel I would expect it to improve the STC rating by less than 10 points.  It appears increasing the drywall thickness may provide the most bang for the buck in making a quieter structure.  It would be helpful to have a listing of STC ratings for SIPS showing any differences for different drywall thicknesses & layering, high-ht versus resiliant channel, SIP thickness, skin type (wood versus, steel), and foam type (polyiso vs. EPS).  Unfortunately this is one area where SIPs don't outshine ICF so there is little motivation for SIP suppliers to have this information.

My stick-built house using 2x6 studs with 4 inches of foam added outside is very quiet. The great-room has a barrel roof (29X45 feet with a radius of 19 feet or so for the arches) , consisting of metal arch trusses on 60 inch centers with 2x6 T&G spruce as the ceiling, with 4 inches of polyisocynate foam covered with goodyear rubber roofing.

Twice a day, when it warms up and when it cools off, it makes a popping and groaning sound for 3 or 4 seconds. Very shocking the first time you hear it. But the roof would hold a JD-450 dozer easy.

Outdoor sounds come in through the windows, not the walls or roof. I think that's true of SIP and ICF buildings too. My shop is 24x48 ICF, really quiet inside.

I live in a 2nd floor condo. A contractor replaced the roof on the building at the end of the summer (new plywood and everything). When it gets very windy (wind gusts over 20-30mph), the skylight in the livingroom (I only have one skylight) makes very load moaning/groaning noises. It actually sounds like a large animal. In the master bedroom, it's almost as if there's no roof, I can hear the wind gusting through and making all sorts of creaking/squeaking and other noises.




_____________
roofing contractors

Posted By Brearley on 09 Jul 2010 07:47 AM
I live in a 2nd floor condo. A contractor replaced the roof on the building at the end of the summer (new plywood and everything). When it gets very windy (wind gusts over 20-30mph), the skylight in the livingroom (I only have one skylight) makes very load moaning/groaning noises. It actually sounds like a large animal. In the master bedroom, it's almost as if there's no roof, I can hear the wind gusting through and making all sorts of creaking/squeaking and other noises.




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roofing contractors

you have a bad seal at the skylight/curb when the wind blows hard enough it is the same as blowing across the top of an empty soda bottle

Okay . . . maybe I need to help clear up any misunderstandings or confusion on the SIP house exterior noise thing:
My comment about being able to hear birds WALK on the roof - totally true.
HOWEVER - we DO live in an extremely quiet house. This SIP house is quiet way beyond our old stick-built house. But I'm not able to tell you why we hear one exterior sound over another.
If I am in the house with all windows closed, I can't hear a car drive up our gravel driveway. I also don't even hear our garage door go up - or even hear my husband walking in the garage toward the door to enter the house. It always surprises me if I haven't SEEN his car drive up the driveway, and he walks in the door! And I have excellent hearing.
On the other hand - I can hear tractors and a passing train on some tracks about a mile away - across open fields. But I'm sure I could hear these things much better if I were in a stick-built house.
As for someone talking on the other side of a SIP wall - me standing inside - them standing outside - can't do it - unless they speak VERY loudly. It seems to be the sounds that happen right against the SIP panel that transfer so well into the interior.
We've gotten used to how loud rain is on the roof. Fluttering shingles on a super windy day is something that took us a while to figure out. We didn't know what the sound was at first. But I'm guessing it happens on all houses - it's just that with a stick built house that has attic space between the roof and the top ceiling, that buffered space doesn't allow the noise to convey to the interior nearly as well.
Thanks for all the responses everyone. I'm feeling a bit more at ease that my house isn't going to fall down around me

The unfortunate situation is that SIP panels are much less sound isolating than a standard wall. We've tested them, and reviewed test data from others. They are a lightweight panel with no air cavity. As such, they transmit sound readily (birds walking).

The only solution is what was referenced earlier. Decouple from the panel, insulate the new air cavity and add drywall. This significantly increases the wall depth, however.

This is a real shame, since the SIP concept is spectacular from a thermal and construction perspective.

Ted;

I have used all types of SIPs,  the panels we have been using the last 12 years do not come with a wire chase, instead we fur out the inside to create a wire chase, at the same time it creates the "dead" 1-1/2 air space and drastically  deadens sound, 6" walls are even much greater than 4" , but even the 4" are quieter than conventional homes

Chris, I'm sure they work fine for you. Part of the issue is that the SIP is filled and essentially behaves as a single mass. When we introduce a small air cavity next to a solid mass, we improve things in the upper frequencies (just as you describe) however there is also a loss in performance in the lower frequencies. See the data and graphics here: http://www.soundproofingcompany.com/library/articles/triple_leaf_effect/

An improvement to what you do would be to resiliently decouple the inner drywall from the SIP, rather than apply rigid non-decoupled furring. This would lower the resonance point of the assembly, giving you a bit more control over the low frequencies.

thanks for providing the useful information

Have these SIP issues been addressed/resolved and if so, what was the solution?:

** SIP roofs creating a very loud popping sound throughout the day (more prevelant in climates with large temperature swings in 24 hours)
** SIP walls transmitting a lot of sound due to the SIP wall being one structural element and not a very good acoustical break

I have read comments from some SIP home owners who swore they would never live in a SIP home again due to the above issues, it was that bad.

yes furring and de-coupling

Posted By cmkavala on 19 Dec 2011 07:56 PM
yes furring and de-coupling

Did they find out WHAT was causing the loud popping?

Is this applicable to steel SIPs or OSB SIPs?

Any pics or diagrams of the furring and de-coupling?

Just as a point of clarification, installing furring channels isn't true decoupling. Also, while the installation of furring may increase STC (a mid- high frequency measurement) it will make the low frequency isolation worse. Such is Mass Law.

The SIPs have this acoustic weakness because they behave as a single mass leaf. The missing functional air cavity defines this. A standard stick bult wall has an outer layer of mass, a middle layer of insulated air, and an inner layer of mass (drywall). This classic Mass-Air-Mass system will yield greater isolation, especially if decoupled.

I built my SIPs in 2007. After interior walls for a bath were added, and the walls attached to the vaulted SIPs ceiling, there was horrific noise with temperature fluctuation. The bath was the ONLY room on that floor - the only interior walls on that floor. The plumber just happened to know exactly what the problem was - the nails attaching the walls to the ceiling were rubbing up and down with heat and cold expansion and contraction. The contractor A) cut all the nails attaching the walls to the ceiling and B) used insulating foam as a kind of glue to attach the walls to the ceiling. The house is now SILENT. When the wind blows at gale force outside, I hardly hear it. The house is very quiet.

The vaulted SIP ceiling is your roof also? If so, I don't know that foam is going to do the trick. That is I don't think you should depend on the foam to hold your roof down. I probably missed something. Anyway, I have a friend that has a SIP roof with ICF walls and he said he attached the roof with long screws metal to metal. Metal anchors in concrete. He was careful to put some type of soft washer on screws to absorb sound should the roof move a bit and it worked great. Regards.

What exactly is 'popping' in a SIP roof?

The area I am in can see 30-40 degree temperature swings in less than 24 hours.

From BuildingScience.com, they claim one get achieve a R-50 or higher just utilizing modern insulation within a standard attic.