I'm building our "forever house" for my family in So Cal. SIPs for the envelope (or K-Tect) and ICF basement.

The issue is Acoustics. I need to acoustically isolate the full basement from the main floor. The finish on the main floor will be bare concrete with a handful of area rugs, so IIC rating is big. I don't want to hear every foot step in the main part of the house. Where the music studio is beneath, I want to get to an STC of 60. I'm open to getting "enough" of an acoustic solution for the main part, then going the extra mile for the studio.

Acoustically, it seems like the Hambro/FastFloor type of floor, would be really noisy. To get decent STC it seems that you have to stuff the joist cavity full of insulation and de-couple the ceiling drywall in the basement - maybe add mass loaded vinyl or something, too. Is that accurate? It seems the same could be said of WarmBoard. Correct me if I'm wrong. Lot's of steps.

Another thought was to use a standard joist and plywood sub-floor, but use two layers of sub-floor with an acoustic blocker between, concrete on top. Has anyone done that? I'm wondering if that would get me to STC 50?, then add insulation and a de-coupled ceiling for the studio.

The best solutions seems to be a monolithic pour using ICF basement walls and Lite Deck. It's got mass, no open cavities and insulation. I have a 9 year old pounding on drums. How much of that low freq is going to get passed a Lite Deck floor with 3" of concrete on it? Can anyone out there testify!

I'm the owner/builder, so creative solutions are welcome!

Thanks.

Thomas. Your most certain noise-stop is mass, and no air channels. IMHO Insul-Deck is FAR better than Lite-deck (just heard from a contractor friend who finished a Lite-Deck job last week, who said he hoped he'd never have to do that again) go to http://www.insul-deck.org/ and ask for local dealers. If you are really concerned about the noise situation, and you want an STC of 60 I think you'll need a 5" slab or better; understand, I am NOT an acoustical engineer. I live in a SIP house, am building an ICF house (almost finished) and the data I have from the two demonstrate that the ICF house FAR outperforms the SIP house; don't shoot yourself in the foot. Have fun. FM

I'm interested hear the differences in Insul-Deck v. Lite Deck. Did the smaller pieces of Lite Deck make for difficult shoring and install? When you speak of ICF outperforming the SIPs, what's the metric? R Value, acoustics, etc?

Appreciate your opinions.

i cannot speak to differences in STC for the two systems - i would think they would be similar but do not have data one way or the other. I don't know what you mean by smaller pieces as they both have similar span capabilities, etc. On the install side, Insul-deck requires less shoring and consequently can be installed for less dollars. I do not know what the price difference between them is. Regarding SIPs vs. ICFs you can achieve the performance of ICFs with SIPs (but at a greater cost).  What are your goals for thermal performance?   What is the configuration of the SIP?   Regards.

Thomas, I wasn't interested enough in the contractor's woes with Lite Deck; next time I see him I'll ask. SIP vs ICF metric? 1- Heat retention, and 2- warm walls, Depending on outdoor temperatures we have a drop of 6-10˚F every winter night in the "great area" of our SIP house (and the house is put together very tightly with excellent roof insulation + good triple pane windows). 1- Over a six day period in the ICF house, mid December, while waiting for the pump to be replaced in the hydronic heating system the whole house temperature dropped only 3˚F. 2- When building the ICF walls we cast thermocouples in place, then drilled into the center of the SIP structure and inserted a thermocouple there. Again in winter, February, an energy auditor & I read the thermocouples in the ICF house to discover an average temperature of 48˚F; the readout on the SIP thermocouple was 34˚F. The wiring up-charge for SIPs can be serious. The only benefit to SIPs in my mind is the 100% nail base on the exterior walls; if you need this in an ICF house you can, for additional cost, apply OSB or plywood prior to installing drywall. Another way to look at the difference is you NEED the concrete foundation, so if ICF is good enough for that, why not the whole building? FM

thomas
i live in an icf/insuldeck house, and have been building like this for 15 years.
call me at 772 225 5404 or email me [email protected]
wir koennen auch auf deutsch darueber sprechen.
peter

Thomas,

The basic principle of soundproofing are Mass Air Mass. Do mass on both sides, seperated by an air space.

I our last studio we did using ICF, the ceiling was contructed as a double joist system with an air space between the joists. It worked out well. 2 layers of drywall on the ceiling site. Upstair flooring was a plywood subfloor with 1/8" layer of lead then 3/4" hardwood.

It worked pretty well. We absolutely never heard anyone upstairs.

The mass you migh achieve with the insuldek proudct would probably be around 44.. To get to 50 you will need 10" ceilings.

a 12" insuldeck floor (9" panel and 3" concrete) with 2 layers of 5/8 drywall on ceiling is stc53.
one layer of drywall is stc 50.

Thanks for the Insuldeck info. Is that assuming that the 5/8 drywall is de-coupled (floated) from the underside of the Insuldeck, or mechanically fastened to the integral stringers? I'm asking, because if I were going to attach drywall to the underside, I think I'd likely use a spacer to de-couple.

Thomas,
As far as I am concerned, a sound proof drywall can be used to eliminate all of your issues.  This drywall has a STC of 70, and is equivelent to 8 layers of regular drywall.  A link below takes you to a decent write-up.  The drywall is typically 3-4 times more expensive than regular drywall though, $30-$40 vs. $10-$20 per sheet.  But you get what you pay for.
 
You would need only insulate the basement ceiling with a cellulose insulation, or spray foam to further prevent transmission of noise.  There is links for both below as well.

I have a tremendous home theatre setup, and plan to build a new home in the next 6 months, and these are the supplies I am looking at to keep from waking my newborn child while watching a movie.  I am building the entire envelope in ICF, adding wall enclosures in ICF to contain the theatre room, and then sprayfoaming or cellulosing the ceiling and wrapping it all in soundproof drywall.


Sound Barrier Drywall


Sound Barrier Insulation


Spray Foam Insulation

Just curious Eli, where are you geographically? FM

I'm glad you brought up Quiet Rock. They're one I've been considering. I've used spray foam insulation on roofs and have to say that our spray foam roof, on a plywood deck with 12" of fiberglass insulation and Brand X drywall, is pretty noisy in heavy rain.

I think my solution is to use Insul-Deck or Lite Deck for the ceiling of the studio space, adding Quiet Rock to a iso channel on the basement ceiling side. The walls will be isolated ICF and the floor will be floated concrete. I think that's about as good as it'll get.

thomas
in the stc tests the drywall was fastened directly to the 22 gauge galvanized furring strips.
these in turn are molded into the eps foam and are therefor isolated from direct concrete sound transmission, i think you could say de-coupled. they are also pre-punched to let the eps mold through the channels, which further reduces sound transfer. i live in an icf insuldeck house with all roofs and floors made of 10" panels plus 3" concrete. the loudest noises during the night are my icemaker kicking out the ice, and my cats chewing the dry cat food.
peter

My first post

Hi Thomas,
Your final solution sounds good. Here is my suggestion.
For the floor you can use a layer of foam to reduce football and other impact noise. Then add a layer of sound dampening wood or quietrock and finally a layer of carpet or tile.

The foam layer should provide good decoupling. This will give good results up to STC 50. You can get more by adding another layer of QuietRock in the basement ceiling, its a good choice for drywall.

Lite Deck publishes a STC rating of 51. I believe that their STC rating is only one of the advantages. Their website is very informative, check it out.

You sure don't want drywall on your floor. And you can't directly damp ICFs. We've tested this in an acoustic lab back in 2005.

David, you work for that company, you should research what you say.