For a MIL siute, 1/4" steel plate works well.

Sound insulation is a complex topic.

I hope you are doing a separate heat/AC system in the basement or one of you is going to be uncomfortable living in the house. Separate systems/ducts will also eliminate the sound transmission that occurs through the ducts.

Very complex topic.

TV, music and talking are pretty easy. Music that has deep bass is a very different animal (and harder) than talking. So you first need to define the music.

The simple and relatively economical way to reduce sound transmission is with specialized drywall. Quietrock is a brand. Green glue is a product between 2 layers of drywall. The green glue and double drywall is a bit cheaper but more labor. Resilient channels is even better but requires careful install. Even thermal style insulation between floors will do something for voices - and is the cheapest option. But the drywall options are more effective.

The other inexpensive and effective option is air sealing. No can lights. foam/caulk all penetrations in ceiling and floor. This makes a surprising difference. And of course, separate HVAC systems between floors.

Door on stairwell?

If you are worried about sound transmission in a new construction house, beef up the flooring and not the ceiling.

Honestly, sealing all openings and doubling up on a thick subflooring with a resilient layer in between will be much better than anything else you can do.

I believe my subfloor was like a 7/8" Advantech over rubber mats over 7/8" Advantech. I run four SVS subs in my theater and you can't hear anything on the floor above. You don't need to use any special rubber material, just find any no-VOC rubber mats and use them.

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Rarely are fancy products worth the money. Quietrock is two thin sheets of drywall with acoustic paste in between them, it is cheaper and better to use two regular drywall sheets and acoustic paste. Assuming you have the extra 1/2" to give.

Thanks everyone! I will review the information you shared with the hubs.

Yes, there will be a door on the stair well, at the top. And the door in the tenant's 'utility space' will also always be closed.

HVAC - the house, with basement, is going to be 3 story. I know the top floor will have it's own thermostat / hvac. I'm not sure what is going on with the basement & main floor. The builder did say that the walkout basement is easy to keep at a steady temp due to it only having 1 external wall. I'll certainly ask them for more information though.

BASEMENT CEILING HEIGHT - is 8 ft. I don't know anything about code or how much 'thicker' the ceiling in the basement can be.

The person that is going to occupy that space actually lives in the MIL in our current single story on-a-crawl-space ranch house. We are all very respectful, quite time after 9:pm on week days and certainly by 11 pm on weekends. No one parties. No one stomps around. I think the biggest offense would be movie nights. But again, it's one of those things that in this tenant-room-mate-land-lord relationship you know a movie is going to end in about 2 hours so we are all fine with it. I just want to feel comfortable having a normal volume voice conversation, and not having to try to be quiet in our kitchen making breakfast on Saturday and Sunday mornings, or doing kitchen clean up in the evenings.

I actually re-thought carpet and pad in the living room... UGH but with two dogs and our horses on the farm (and that life style in general) I think we'd regret the carpet pretty quickly. I really think we would. Hmmm. I'm also not sure we'd love the look of having carpet JUST in the living room. We have wood-looking sheet vinyl in our entire house right now and we really like the way it looks going from room to room.

I did the math for using something like Rockwool Safe N Sound in the basement ceiling and we'd only need 7 bags of it to go just beyond the tenants ceiling space, at a cost of about $300. To me that isn't bad at all.

Sealing all holes between basement ceiling and main space floor with caulk or spray foam wouldn't be expensive or a huge labor so that is another item on the 'easily doable' list.

I read an article that talked about a padding that could go under luan / underlayment (which will go on top of the sub floor so that the OSB doesn't show through the sheet vinyl). I also read that using plywood vs luan is helpful. Hmmm.

I just sent an email to the builders (who are fantastic, they really have been great with us) asking if we could have a conversation about attempted sound buffering:

*************

A few things I was reading up on made these (seemingly doable) suggestions:

1. Seal all holes in ceiling / floor with caulk or spray foam

2. Do not use canned lights in the basement ceiling

3. ‘Insulation’ type sound proof products in the ceiling joists of the basement (We looked up Rockwool ‘Safe And Sound’ and did the quick math for the area of the tenants apartment and for 7 bags of it would cost us $300)

4. Use a sound deadening underlayment product suitable for sheet vinyl (I did read ½” cork is not usable with sheet vinyl but that there are other products that are) and plywood not luan.

And… perhaps not as easy to do anything about but…

5. Consider the duct work / returns in a shared HVAC system

6. Sound proofing ceiling material / drywall

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We'll see what we come up with. :)

The basement needs a separate HVAC system. If you are only going to have a 2 zone system, in the summer when you run the AC on the first/main floor, there is a very good chance the person in the basement will be too cold.

Maybe do a mini-split system in the basement so your tenant can control their own heat and AC.

Sound proofing - First things first... get rid of the vinyl. Vinyl does NOT like to have underpad used with it. I would say 99% of ALL VINYL products do NOT allow underpad to be used with it. You have just discovered the MASSIVE DOWN FALL of vinyl (condo owners have been learning this lesson by the HUNDREDS on a daily basis).

I like the idea of a water proof LAMINATE like Aquaguard. It allows 1/4" or even 1/2" cork underlay to be used. The 1/2" cork underlay kills 22 dB of sound ALL BY ITSELF! That is EQUAL to a REGULAR subfloor+ceiling! That's some SERIOUS sound deadening!

Secondly, (after you have chosen to work with Aquaguard and cork) I like to recommend DOUBLE STUFFING the ceiling with the Roxul Safe N Sound. So instead of 7 bags....purchase 14 and CRAM the ceiling full of this stuff. That makes a HUGE difference. A single layer is worth 5-7 dB. A double layer is 10 - 12 dB (notice how the cork is BETTER than the Roxul????).

Between the cork (22 dB) and the Roxul (12 dB) and the regular floor-ceiling assembly (25 dB) you will have created 59 dB worth of insulation....just by working with two items (1/2" cork and double layer Roxul).

To be clear, a 12 inch CONCRETE SLAB is roughly 55 dB!!!! You find those in luxury apartments in New York over looking Central Park (with a purchase price of $5M).

If you use an acoustic tile for the ceiling, you will add another 5-7 dB...but the cost will be much higher than the cork or the Roxul combined.

Yes, wrapping your HVAC and your plumbing will do wonders. Some of the best sound sharers are metal ducts/pipes. Remember playing "telephone" with soup cans and string? Yah. Soup CAN = metal.

Personally, I would move away from vinyl and look at water proof laminate. It will give you the same options (tough, easy to care for...doesn't mind "wet" or mud) and it offers MASSIVE advantages as to the ACOUSTIC underlayment (underpad) that vinyl does NOT let you play with.

Good luck. I've had people use this system above and LOVED IT! It's cheap, fast, easy and doesn't require special analysis to get things into place. A regular building crew can do this without any issues. There is no special training or need for specialized crews to come in and do the work.

In essence, if you need sound proofing, stay away from vinyl flooring.

Between the cork (22 dB) and the Roxul (12 dB) and the regular floor-ceiling assembly (25 dB) you will have created 59 dB worth of insulation....just by working with two items (1/2" cork and double layer Roxul).

STC's are not additive, so you can't simply add together 22+12+25 and get a rating of 59.

First, let's talk about what the ratings are and what they mean. The STC (Sound Transmission Class) assigns a number that represents the transmission loss, or decibel reduction of sound, through a material. However, in reality every material dampens certain frequencies better than others. So the STC uses attenuation across 16 frequencies to come up with an average attenuation, in other words an average decibel reduction.

Two materials might attenuate the same frequency well but be worse at other frequencies and do little to add to each other. Also, every additional decibel reduction requires a little more effort as the curve is not linear. So even doubling up on the same material doesn't double the attenuation even at specific frequencies.

Many materials perform well in the mid range, and the STC rating doesn't go below 125Hz and is biased towards voice level frequencies. The dB reduction given by testing is complete garbage when it comes to amplified sound and or movies, especially, if you have any type of subwoofer. For attenuation of low frequencies mass is king.

Finally, you are not going to get anywhere near 60 decibel reduction on any stick built construction barrier that isn't decoupled. You can double and triple stuff insulation all day long but you are still going to move sound through the joists.

The above cork + Roxul + floor assembly is probably going to get you around a 45-50 dB reduction. For reference the floor assembly alone is probably around a 35-40 dB reduction without any insulation or cork. A decoupled 4" wall with standard materials and fiberglass insulation is going to approach 55 dB reduction.

Some of the best sound sharers are metal ducts/pipes. Remember playing "telephone" with soup cans and string? Yah. Soup CAN = metal.

But it works better with paper cups. When the string is tight, the vibration of the speaker's cup is transferred through the string to the other cup. It doesn't work unless the string is tight. The vibration of the string transfers through to vibrate the receiving cup. Materials that vibrate easier (are less dense) work better. This is exactly what happens without decoupling.

This is a common subject, but unfortunately many of the responses are "solution-oriented" and don't understand the acoustic issues involved.

Sound transmission in a building can occur in one of three, or a combination, of ways:

1. Airborne

2. Impact, or

3. Flanking transmission

If you are serious about reducing or mitigating sound, you will have to address all three methods of transmission.

@bry911 - Those aren't STC....those are DELTA IIC ratings (that's why they are "so low"). And because they are Delta IIC ratings they are SUPPOSED to be additive...that's the advantage of them. Delta IIC does not relay on the SYSTEM...it only relies on the MATERIAL (cork+floor). That's why it is additive.

And cork rates HIGH in the HIGH frequency levels (airborne vocal range and TV noise). It is 'average' when it comes to lower frequency noises. Foot steps are dampened by only 1 thing: carpet pad. If subwoofers are in play then having them decoupled from the wall or moved away from the floor (for the upper unit) will help immensely. By the sounds of the OP, I don't think subwoofers are going to be the issue.

And yes, the TYPE of noise intrusion (flanking transmission, etc) will create pockets of vulnerability - such as pipes and duct work and underneath doors. Those are the toughest things to diagnose. If you simply go ahead and do your best and wrap everything you can think of with acoustic pipe insulation, you will get rid of 90%. The other 10% will simply have to be lived with because that's what happens in a multiple family dwelling.

those are DELTA IIC ratings (that's why they are "so low"). And because they are Delta IIC ratings they are SUPPOSED to be additive...that's the advantage of them. Delta IIC does not relay on the SYSTEM...it only relies on the MATERIAL (cork+floor). That's why it is additive

Yes but the OP notes, "We are not overly concerned about physical noise (walking) as there are no children or rambunctious pets (or people) living on the main floor. We are more concerned with noise from the TV, music or talking."

Delta IIC literally means the Change in Impact Insulation Class. It is designed as a metric for impact noise (footfalls), it is not designed to measure amplified sound as the OP wants. As bad as STC is, and I agree it is bad, it is still a lot better for television, music and talking.

Delta IIC also assumes no floor movement. The test is done by putting various subfloor materials over six inches of concrete and measuring the noise of steel hammers striking before and after subflooring is added. In a stick built residential structure the flooring will behave differently.

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If you want to know how to control sound coming from televisions and stereos read the AVSforum soundproofing master thread. It is a lot of people, some with significant acoustic credentials, discussing this very topic.

SJ McCarthy - I hesitate at anything other than sheet vinyl due to our life style. Horses (yes they live outside but we don't stop at the door to remove muddy boots) and two large farm dogs (that also don't stop at the door to wipe muddy paws), and a cat that likes to puke frequently. :-\

In our current house (on crawl space) we got rid of the carpet and did sheet vinyl with luan over the OSB sub floor. 4 years later and for the money (about $3,500 for 1750 sq ft) we LOVE this floor. It has been so durable and easy to care for, and looks great. I even dropped a book shelve and cut the floor and we took a knife, cut out the plank 'plank' on the pattern's seam and put a replacement in with glue. You really can't tell unless you know.

I was reading up on some products that can be used with vinyl sheet flooring... in kind of a sub-floor - product - plywood - vinyl floor sandwich. Could cork be used between sub-floor and plywood (that is if it is cheaper than the other rubber based products)? The space on the main floor is about 840 sq ft.

And no, we're not having dub-step parties. We usually wind down in the evenings watching an episode or two of The Office and get up on Saturday and Sunday mornings and make breakfast rather early (ie normal noise in the kitchen).

Yes...cork can be used between plywood/luan as an acoustic sandwich. You will glue the cork to the subfloor plywood. Let it cure (24 - 48hours). Then glue the luan to the cork (let cure 24-48 hours) and then glue the sheet vinyl to the luan (let cure for 24-48 hrs).

Again, so long as you work with 1/2" cork, you will be adding 22 dB of acoustic insulation for a mere 1/2" (12mm) of floor height. The same acoustic insulation for rubber = 8mm. Cork and rubber have the same acoustic profile. Rubber just does it with slightly less thickness. I've figured out that it is a 3:2 ratio. You need 3mm of cork to achieve the same as 2mm of rubber.

Therefore 8mm of rubber (at $5+ per square foot) = 12mm of cork ($1.49/sf from iCork Floor LLC). Both will offer 22 dB (or so) of acoustic insulation.

Cork does not off gas whereas Rubber can get pretty nasty when it gets warm...as in people with asthma have been known to be hospitalized because of rubber underlayments. People with chemical sensitivies are also affected by rubber's off gassing. To get rid of the off-gassing with rubber you need to move to the HIGH END product that is around $8/sf....which is roughly the same price as a rubber floor.

Canada's National Research Council's report

Your information on cork is simply not correct. This is a well researched and thoroughly tested topic. Cork does almost nothing at all for airborne sound.

It isn't even that great for impact sound reduction as you can clearly see from above.

If you are worried about transmission of voice, television and music, cork might be the worst product there is. You might as well throw money on the floor and save the time and trouble of using cork. One reason I like the AVS forums is that there are lots of links for technical data and real unbiased test results in a variety of environments, it is one of the best starting points for sound control information that I have found.

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I've figured out that it is a 3:2 ratio. You need 3mm of cork to achieve the same as 2mm of rubber.

Therefore 8mm of rubber (at $5+ per square foot) = 12mm of cork ($1.49/sf from iCork Floor LLC). Both will offer 22 dB (or so) of acoustic insulation.

Actual results from a real unbiased test on impact sound (note still not talking voice, television and stereo)...

Increasing the thickness of a resilient material increases the compliance and decreases the frequency where the improvement in impact sound pressure level begins. This behavior is exhibited by the shredded rubber mat in Figure 16; generally, the thicker the layer the greater the reduction in the impact sound pressure level at any frequency.

Figure 16: Reduction in impact sound pressure level for four thicknesses of shredded rubber mat on 100-mm concrete slab.

The two thicknesses of cork tested behaved quite differently. In this case, there is no difference in improvement between the 6-mm layer and the 12-mm layer (Figure 17)

Figure 17: Reduction in impact sound pressure level for two thicknesses of cork on 100-mm concrete slab

Can we finally put the soundproofing of cork to bed?

Sure....but you realize that cork is one of the most cost effective materials on the market. It is easily renewable resource without off gassing.

And cork does AWESOME at airborne sounds...I've already stated it is 'average' when it comes to impact noise. It starts to get "efficient" about the 2000hz range. All of that range is airborne. In fact the most annoying sounds (ranked around the 4000hz range) are the "sweet spot" for cork. Cork will "kill" the annoying noises (think fingers on a chalk board, jackhammers, telephone "busy signal", etc) that are airborne.

I've seen the raw data for 12mm cork (remember cork comes in different densities and granulation size so not all cork underlay is created equal) with a 220kg/meter cubed density. It is impressive.

I've seen the raw data that concludes that anything above 2600hz is "killed" by high density cork. In fact it reduces the 72 dB noise to 9 dB....which is the background ambient noise for the testing chamber. Which is to say....those frequencies didn't make it through to the test chamber.

Argue all you like....but cork's ability to insulate against sound is ranked #2 in the world (#1 being rubber). It's ability to insulation for thermal loss is ranked as #2 in the world (#1 being felted wool). There is no other single substance that we know of that carries this level of thermal AND acoustic insulation ranking.

Many consumers like what cork can do as well as it's price tag. The two put together offer the consumer a decent option with a decent price tag with a decent or more than decent outcome. The price and the off-gassing alone are enough for consumers to choose cork.

Just to be clear, cork is double the cost of ultra low VOC Green Glue, is much harder to install, and really has no advantage at all. But please don't take my word for it. Look at the report, pay special attention to the part where sill gasket outperforms cork...

Then find other sources and do some reading. Just do your own research. Find studies that have actually measured the results, fortunately the sound industry has commissioned a lot of them. Look at recording studio sound isolation, there are hundreds of peer reviewed studies out there and none of them find cork quite as sexy as SJ McCarthy...

Everyone wants to argue about "solutions". No one wants to identify how to deal with all three of the sound transmission characteristics.

These threads always degenerate into the same confused rhetoric.

With respect Virgil you are simply not correct. I can only assume you didn't read the entire thread. We are not arguing about dealing with sound transmission, we are arguing about the effectiveness of cork as a dampening layer. In other words the ability for cork to convert sound waves into heat.

Sorry...the title of the thread threw me--"...Sound proof between floors, new construction..." It would have been clearer if the title had addressed flooring as the topic of concern, or even more specifically "...cork flooring as the concern"!

Ahh... Sass...

I do like a little bit of that.

I am encouraged by your newfound respect for the asked question. I am interested to see your future posts since you will no longer be encouraging posters to get an architect when that is not the question they asked.

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ETA: Just to be clear as I look back over the thread, all three methods have been discussed by most posters...

ONE OF MANY DISCUSSIONS ON THIS THREAD OF FLANKING TRANSMISSION

When the string is tight, the vibration of the speaker's cup is transferred through the string to the other cup. It doesn't work unless the string is tight. The vibration of the string transfers through to vibrate the receiving cup. Materials that vibrate easier (are less dense) work better. This is exactly what happens without decoupling.

ONE OF MANY DISCUSSIONS ON THIS THREAD OF AIRBORNE TRANSMISSION

The other inexpensive and effective option is air sealing. No can lights. foam/caulk all penetrations in ceiling and floor. This makes a surprising difference. And of course, separate HVAC systems between floors.

ONE OF MANY DISCUSSIONS ON THIS THREAD OF IMPACT TRANSMISSION

Increasing the thickness of a resilient material increases the compliance and decreases the frequency where the improvement in impact sound pressure level begins. This behavior is exhibited by the shredded rubber mat in Figure 16; generally, the thicker the layer the greater the reduction in the impact sound pressure level at any frequency.

So far as I can see all three items of sound transmission have been extensively addressed. Which one specifically do you feel was not?

I particularly like the discussion of cups and strings as it applies to residential acoustic principles and design solutions. I presume you are suggesting that cups and strings be abandoned in future residential designs...? But then, how will one contact the next floor for a bowl of Wheaties...?

Cups and strings are exactly how flanking transmission is demonstrated in physics classes.

Let's actually set this right.

There are NOT three different methods of sound transmission, that is either way over-simplified or over-complicated, depending on the view that you want to take.

Building designers have created a checklist to deal with building design and sound transmission. But that is because building designers have enough stuff to deal with without getting into the physics of mechanical waves when designing a building.

There is exactly one method of sound transmission in buildings, on earth, in space, etc. Sound is a mechanical wave, or energy that travels through matter by disturbing it. More specifically even, it is the displacement of matter from its equilibrium position and that displacement as well as the rebounding of material is what moves sound through all matter, including air and walls, it is also the lack of matter to disturb that stops sound from moving through outer space.

Sound is easy to understand as work, as sound encounters various forms of matter it expends effort to move through the material, even air, that is why decibels are lessened over distance. There are really only two ways to reduce sound, require more work and convert the work (technically there are three, but locate your basement in outer space seems a bit extreme). More mass means sound has to work harder to move the material, not unlike throwing a boulder compared to throwing a pebble. So one simple way to reduce sound transmission is to add more mass. The other is to convert sound to other forms of energy, usually heat energy. This is what resilient materials such as rubber and cork do. Think hitting someone with a bat versus hitting someone with a foam pole.

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Now all of this may seem immaterial to the discussion at hand but it really isn't. Building designers, especially when designing commercial buildings, have broken sound transmission into three very broad categories that they need to address in the design of a building. However, not every situation requires considering those things as they are presented, nor are those three things adequate in other situations. The final, and really more important point for homeowners, is the cost of effective design versus the cost of effective treatment.

No one who actually works in theater installation and design really spends their day looking after these "three sound transmission characteristics" of building design. And no one creating sound isolation booths for recording studios would think addressing those three things are remotely adequate.

I have both a home theater and a sound isolation booth in my house. There are thousands of installers, and hundreds of home theater and listening room designers who all use the same four steps for sound proofing: (1) sealing, (2) adding mass, (3) decoupling, and (4) dampening (note: that dampening is often separated into dampening and absorbing for ease of understanding). Any approach using these four steps, even in a cost effective manner, will adequately address sound transmission for most needs. Just to be clear it absolutely deals with airborne, flanking and impact transmission, it is well detailed in the material I directed the OP to. So any assertion that no one has dealt with that, is absolutely wrong.

If you are building a sound isolation booth for a home recording studio, this is a good start, but by no means complete. However, you are going to have to get into specific attenuation at that point, at which time I would advise visiting the gearslutz.com or SoundonSound.com sites to get more information.

If you seriously want to understand and design for acoustical privacy, hire an acoustical engineer.

If you want to understand accounting, hire bry911.

Don't rely on string and paper cups unless you are in a physics lab.

When losing an argument it is always easy to reach for the ad hominem fallacy, to many people it will appear as a victory. Whether someone is right or wrong is independent of their training. People who are not acoustical engineers effectively soundproof houses every day.

If you seriously want to understand and design for acoustical privacy, hire an acoustical engineer.

They want to block television noise from flowing too freely from the upstairs to the downstairs and you seem to think that they are constructing the Cone of Silence.

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However, if you would like to ask questions of acoustical engineers please consult any of the sites that I referred you to that actually have acoustical engineers.

When you are done. come back and let us know how many said anything about the "three sound transmission characteristics."

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If you want to understand accounting, hire bry911.

Since I am an accountant let me help the OP.

The Net Present Value of hiring an acoustical engineer to solve a problem that has been solved thousands of times already.

Don't rely on string and paper cups unless you are in a physics lab.

Please note the many times flanking transmission was talked about in this thread.

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You came to this thread not to offer any help or advice, but to play Sage and Wise Papa Bear. The problem being, your input wasn't sage or wise, it was simply the same tired song you always sing with a few new lyrics.

"They want to block television noise from flowing too freely from the upstairs to the downstairs and you seem to think that they are constructing the Cone of Silence."

Yes... that about sums it up.

We got the appraisal back from the lender based on our first draft house plans, and we close on our land last week.

We are having a pre-construction meeting this Friday. We did find out (from what was sent for the appraisal) that each floor (basement, main floor, 2nd floor) will have its own HVAC.

We're not constructing a sound booth and were not trying to mask dub-step or Romper Room parties. We just wanted to know of some easy-and-affordable amendments we could ask the builder to make to help dampen average household sounds (from respectable adults) between the basement and main floor (based on the floor plan I posted) without the builder looking at us like we grew a second head, or grinning like we're millionaires.

Thank you for the responses.

Have you considered 1.5" of light-crete between the floor sheathing and finished floor?

On the advice of acoustic engineers, what has worked well for me between stacked apartments, restaurants and offices or combinations of those uses is ceiling drywall supported by 1/2" deep resilient channels or a 1 1/4"+ proprietary resilient suspension system.

The former is cheaper and commonly used and probably adequate for your needs. The latter might accommodate Romper Room parties. I recommend 5/8" drywall with no penetrations. Blueboard veneer plaster or a double layer of 1/2" taped drywall helps too. 6" of rock wool acoustic insulation would also help.

Resilient Channel link

proprietary resilient suspension system link

IsoMax link