I am in the process of building an addition using IFC. We are looking at SIP's for the roof. Can anyone comment on how well SIP's work to deflect the noise from Navy Fighter Jets that practice in the near distance and sometimes fly overhead. As a vaulted ceiling, I am guessing a 10" - 12" SIP's roof will be warm, but are they quiet? Any comments? Also, How about SIP's for exterior walls against the sound of Fighter Jets? Any comments?

There has been some debate about SIP and noise transfer. I believe SIPS by themselves have a STC of 28. There are two sources of noise; one being the SIP itself from thermal expansion & contraction rates and the other being from outside sources. Being that SIPs are sort of a monolithic form the SIP itself can make noise during the external temperature changes. One way to stop the noise transfer is to decouple the SIP from the sheet rock wall. This is done with using resilient hat channels with rubber isolators as seen here: Resilient Sound Clips

You are creating an (1) air space and decoupling the SIP from the drywall by using rubber isolators (2), this stops noise by using those two methods.




Here is an older GBA THREAD on this exact topic. It is my opinion that resilient decoupled hat channels are MANDATORY to stop unwanted noise when using SIPs. The above product when installed correctly can improve sound by 20 STC points or a 8-10 db. drop.

I have a full SIP envelope, 6" thick walls, and 8" roof with a metal skin on top, and I find it very quiet. However, I live out in the country so I have very low ambient noises. I have found the windows to be the main noise generator. We just had a very heavy rain shower, and I do hear the rain but it is muted and mostly from the metal roof. If my windows are open ( most of the time) I can hear the highway traffic noises which are about 1/3 mile away. Dan

Posted By Lbear on 01 Jul 2013 02:39 AM
There has been some debate about SIP and noise transfer. I believe SIPS by themselves have a STC of 28. There are two sources of noise; one being the SIP itself from thermal expansion & contraction rates and the other being from outside sources. The above product when installed correctly can improve sound by 20 STC points or a 8-10 db. drop.

Great suggestion - Thanks! Would you use these for the sheetrock on the walls also?

Posted By dr99dragons on 01 Jul 2013 10:42 AM
I have a full SIP envelope, 6" thick walls, and 8" roof with a metal skin on top, and I find it very quiet. We just had a very heavy rain shower, and I do hear the rain but it is muted and mostly from the metal roof. If my windows are open ( most of the time) I can hear the highway traffic noises which are about 1/3 mile away. Dan

Dan, Thanks for the info. Did you put a sheet of styrofoam between your roof SIP's and your metal roof - or just install the metal over the OSB?

I don't know anything about it, but perhaps this would help?

http://www.homedepot.com/p/440-1-2-in-x-4-ft-x-8-ft-R1-2-Sound-Board-206136/202090212

Also consider foam furring strips and a cellulose or mineral wool filled gap under the interior drywall. It will help for sound and add insulation.

A double layer of 1/2" drywall definitely helps. "Green Glue" between them helps even more.

Posted By Roger R on 01 Jul 2013 01:00 AM
I am in the process of building an addition using IFC. We are looking at SIP's for the roof. Can anyone comment on how well SIP's work to deflect the noise from Navy Fighter Jets that practice in the near distance and sometimes fly overhead. As a vaulted ceiling, I am guessing a 10" - 12" SIP's roof will be warm, but are they quiet? Any comments? Also, How about SIP's for exterior walls against the sound of Fighter Jets? Any comments?

Roger,
in2004 we built a SIP home 6" walls and roof near MacDill AFB (job was at corner of MacDill & Wyoming) there were never any issues with jet noise, but I can say that lower piched sounds like helicopters, prop engine planes and Harleys are more noticable in a SIPs roof
high pitched jet engines are not noticeable at all,
the thicker the panel the less sound transferrance, I would recommed at least a 8" thick roof

Posted By Roger R on 01 Jul 2013 12:24 PM

Posted By Lbear on 01 Jul 2013 02:39 AM
There has been some debate about SIP and noise transfer. I believe SIPS by themselves have a STC of 28. There are two sources of noise; one being the SIP itself from thermal expansion & contraction rates and the other being from outside sources. The above product when installed correctly can improve sound by 20 STC points or a 8-10 db. drop.

Great suggestion - Thanks! Would you use these for the sheetrock on the walls also?

Yes, most definitely.

A typical wood frame 2x6 wall has an STC (sound transmission class) rating of 32. A SIP by itself is around 26-28 STC. Once you utilize a decoupled hat channel and drywall, you can bump that easily into the high 30's or low 40's for the STC. Probably the highest STC rating is going to be a mass concrete wall like ICF. A 6" core gets around a STC rating of 53.

I emphasize the decoupled part because according to the sound engineers I spoke with the decoupling of the panel must be done to prevent certain frequencies from being transmitted. Remember, sound is just vibration and the rubber isolator stops the vibrations from being transmitted from the SIPs to the hat channels.

Do you think a metal roof should utilize these rubber channels, or would a 2" styrofoam sheating suffice? I have used the styrofoam sheeting before, to cut the sound of rain on the metal roof - but that's as far as my knowledge of styrofoam and sound goes. The rubber channels would "raise" the metal up off the OSB, which could be problematic when someone walks on the roof, etc...

Posted By Roger R on 01 Jul 2013 07:05 PM
Do you think a metal roof should utilize these rubber channels, or would a 2" styrofoam sheating suffice? I have used the styrofoam sheeting before, to cut the sound of rain on the metal roof - but that's as far as my knowledge of styrofoam and sound goes. The rubber channels would "raise" the metal up off the OSB, which could be problematic when someone walks on the roof, etc...

Are you talking about an OSB SIP roof or a Steel SIP roof?

I would NOT use hat channels on the outside of a roof. It's not designed to be used in that way.

If it's an OSB SIP roof, I would use the following Building Science Detail on the roof for two reasons; one to prevent SIP rot and the other to help with noise suppression:

Building Science Wood SIP Article

OSB SIP roof - not metal. Great article, thanks.

I put down 1x2's to screw into, and I used a standing seam metal sheet (either 5 or 7 crimps, I don't remember). I wanted an air space between strand board and the metal. Correct, you do need to be careful where you put your feet up there. With 8" of foam I did not feel I needed more insulation, and except for the 2 cold and 2 hot months, my electrical bill runs in the mid $30's per month, and I'm all electric. For the 4 odd months I run about $85/mo. The footprint is 2,788 sq. ft. on one level. I used as many passive heat/cooling techniques to keep the monthly bills as low as possible like triple pane windows, window quilts, air-locks for the exterior doors, and adequate roof overhangs. With such a "tight" house I read articles warning me against any kind of open flames that would cause lower oxygen levels and/or carbon monoxide in the house. One tip, I could have saved around $25,000 on the cost of stone floors (radiant floor heat) by simply using colored cement. GL Dan

My house seems pretty quiet with a roof detail similar to the detail Lbear shows, although I don't have a noise problem such as you describe. You might consider the use of "Green Glue" under your drywall. I cannot give you any real evidence that it works but google it and see what you think.

Dan, 5-V crimp and standing seam are two different roof types

Hey cmkavala you're right, I wasn't thinking. My roofer and I had discussed both types. I looked at the roof this morning and it is a 5 crimp. Thanks for catching that for me. Dan

I talked to the salesman at the SIP factory yesterday and he told me that the problems in the article http://www.buildingscience.com/documents/insights/bsi-036-complex-three-dimensional-air-flow-networks
can be solved by:
Correctly using plenty of glue and spray foam when attaching the SIP roof panels and by covering all interior ceiling SIP joints with "SIP" tape. He said the problems come from joints that let ceiling moisture sneak through and condensate under the roofing materials.

Posted By vb on 02 Jul 2013 09:09 PM
My house seems pretty quiet with a roof detail similar to the detail Lbear shows, although I don't have a noise problem such as you describe. You might consider the use of "Green Glue" under your drywall. I cannot give you any real evidence that it works but google it and see what you think.

I will use "Quiet Rock" on the interior with the rubber clips. I think 'Green Glue' needs to adhere to the bottom OSB. I'd take the rubber clips over glue - in this case. My son has used Green Glue, and thinks it's good, but I think the clips would be better and less money, as Green Glue is spendy.

Posted By dr99dragons on 02 Jul 2013 11:26 AM
One tip, I could have saved around $25,000 on the cost of stone floors (radiant floor heat) by simply using colored cement.

Dan, We have colored cement in the existing structure and were going to do the same in the addition - although the price of concrete coloring nearly doubles the price per yard for the concrete. What did you mean by "stone floors"?

Green Glue is spendy

Some have reported that it still works well with as little as 1/2 tube between two 4x8 sheets of drywall.

Posted By Roger R on 04 Jul 2013 02:16 PM
I talked to the salesman at the SIP factory yesterday and he told me that the problems in the article http://www.buildingscience.com/documents/insights/bsi-036-complex-three-dimensional-air-flow-networks
can be solved by:
Correctly using plenty of glue and spray foam when attaching the SIP roof panels and by covering all interior ceiling SIP joints with "SIP" tape. He said the problems come from joints that let ceiling moisture sneak through and condensate under the roofing materials.

The one problem still remains is that if the top layer of roof OSB SIP gets wet, it cannot dry properly due to the EPS underneath it. When one puts up a layer of OSB sheathing on a homes walls, they will furr or strap the siding, this leaves an air venting channel gap between the OSB and siding to let it dry out. With an OSB roof sheathing, if the roof gets wet, the bottom of the OSB can still dry as it's exposed to the attic air.

I'm not sure what he meant by using "plenty of glue and spray foam" as all SIPs should have a precisely metered amount of adhesive placed on to the panels. Increasing it does not stop SIP rot due to entrapped moisture. The SIP tape will help the joints.

When wood gets wet it needs to dry out or rot will ensue. That is why they vent walls and roofs. They know that the wall and roof cannot be made 100% waterproof and whatever water/moisture gets on it, that it needs to dry off. Hence the venting.

Here is a wood SIP wall with a poorly designed drainage plane and overhangs. If not allowed to dry out, all wood walls will rot, SIP or not.